CopghtN COPYRIGHT DEPOSIT Market Dairying and Milk Products BY JOHN MICHELS, B. S. A., M. S. Professor of Dairying and Animal Husbandry in the Milwaukee County (Wis.) School of Agriculture and Domestic Economy Author of "Creamery Butter-Making" and "Dairy Farming" SECOND EDITION, REVISED AND ENLARGED ILLUSTRATED WAUWATOSA, WISCONSIN PUBLISHED BY THE AUTHOR 191 2 All Rights Reserved COPYRIGHT, BY JOHN MICHELS • 1909 and 1912 I CLA3 19603 Ml PREFACE. Dairy instruction has hitherto been confined chiefly to the economical production of milk and the manufacture of butter and cheese. Yet those who have thoroughly studied the subject must admit that market dairying deserves fully as much attention as either the econom- ical production of milk or the manufacture of butter or cheese. The subject of market dairying presents two very im- portant aspects : One is to educate dairymen to produce better and more wholesome milk; the other is to instruct them in all the economies relating to their business so as to insure maximum financial returns. For a number of years the author has been brought face to face with the problems relating to market dairy- ing. He has been actrvely engaged in the production and marketing of sanitary milk and cream, and in the manu- facture and marketing of ice cream, cottage cheese, and skimmilk-buttermilk. The markets and diiry conditions of the country have been thoroughly investigated and new methods and plans have been developed, some of which have already been published in bulletin form or otherwise. The production of this volume is, therefore, largely the result of the knowledge and experience thus gained, and the realization of the urgent and increasing needs along this line of dairying. An attempt has been made to so arrange the material that it might answer the needs of both the classroom and the dairyman who cannot attend a dairy school. John Michels. April i, 1909. PREFACE TO SECOND EDITION. In preparing the second edition of Market Dairying, an attempt has been made to cover the entire subject of market milk as completely as possible, and to include instruction in the various side-lines which milk dealers may engage in at considerable profit. The subjects of butter and cheese making have also been accorded con- siderable space in order to satisfy the needs of those who are looking for information not only on the sub- ject of milk but on the manufacture and handling of the common milk products as well. Practically every chapter has been revised and ampli- fied. This, together with the addition of fifteen new chapters, has nearly doubled the number of pages found in the first edition. The constant aim in the present revision has been to adapt the book for class instruction, but it is believed that the scope and treatment will also justify its use as a reference book by all milk dealers as well as butter and cheese makers. TABLE OF CONTENTS. Page. Chapter I. Chemical and Physical Properties of Milk 7 Chapter II. Bacteria and Milk Fermentations 20 Chapter III. Sanitary Milk Production 29 Chapter IV. Cooling and Aeration of Milk 39 Chapter V. The Babcock Test 48 Chapter VI. Composite Sampling 59 Chapter VII. Sampling and Testing Cream 65 Chapter VIII. The Lactometer and Its Use 75 Chapter IX. Acid Tests for Milk and Cream 83 Chapter X. Creaming 90 Chapter XI. Cold Storage 97 Chapter XII. Pasteurization 104 Chapter XIII. How to Secure a Good Market 117 Chapter XIV. Marketing Milk and Cream 121 Chapter XV. Profitable Side-Lines 132 Chapter XVI. Starters or Lactic Acid Cultures 135 Chapter XVII. Cultured Milk 147 Chapter XVIII. Skimmilk-Buttermilk 154 Chapter XIX. Ice Cream Making 157 Chapter XX. Modified Milk 170 Chapter XXI. Soft and Fancy Cheese Making 175 Chapter XXII. Certified Milk 183 Chapter XXIII. Relative Value of Milk and Its Products 186 Chapter XXIV. Detection of Tainted Milk and Cream.. 190 Chapter XXV. Detection of Preservatives and Dirt.... 195 Chapter XXVI. Judging Milk and Its Products 200 Chapter XXVII. Buying and Selling on the Butterfat Basis 211 Chapter XXVIII. The Care of Milk in the Home 216 Chapter XXIX. Keeping Accounts 220 Chapter XXX. Control of City Milk Supply 226 Chapter XXXI. Buttermaking 239 Chapter XXXII. Marketing Butter and Cheese 263 5 TABLE OF CONTENTS Page. Chapter XXXIII. Butter Overrun 274 Chapter XXXIV. Cheddar Cheese Making 278 Chapter XXXV. Creamery and Factory Dividends 287 Chapter XXXVI. Mechanical Refrigeration 296 Chapter XXXVII. Washing and Sterilizing Milk Vessels. .306 Chapter XXXVIII. Dairy Houses 312 Chapter XXXIX. City Milk and Ice Cream Plants 320 Chapter XL. Boiler and Its Management 326 Chapter XLI. Water and Ice Supply 337 Chapter XLII. Sewage Disposal 343 Appendix -. 349 Index 369 MARKET DAIRYING. CHAPTER I. CHEMICAL AND PHYSICAL PROPERTIES OP MILK. Milk, in a broad sense, may be denned as the normal secretion of the mammary glands of animals that suckle their young. It is the only food found in Nature con- taining all the elements necessary to sustain life. More- over it contains these elements in the proper propor- tions and in easily digestible and assimilable form. Microscopic appearance of milk showing relative size of fat globules and bacteria.— Russell's Dairy Bacteriology. Physical Properties. Milk is a whitish opaque fluid possessing a sweetish taste and a faint odor suggestive of cows' breath. It has an amphioteric reaction, that is, 7 8 MARKET DAIRYING it is both acid and alkaline. This double reaction is due largely to acid and alkaline salts and possibly to small quantities of organic acids. Milk has an average normal specific gravity of 1.032, with extremes rarely exceeding 1.029 an d 1-033. After standing a few moments it loses its homogenous character. Evidence of this we have in the "rising of the cream." This is due to the fact that milk is not a perfect solution but an emulsion. All of the fat, the larger portion of the casein, and part of the ash are in suspension. In consistency milk is slightly more viscous than water, the viscosity increasing with the decrease in temperature. It is also exceedingly sensitive to odors, possessing great absorption properties. This teaches the necessity of plac- ing milk in clean pure surroundings. Chemical Composition. The composition of milk is very complex and variable, as will be seen from the fol- lowing figures: Average Composition of Normal Milk. A com- pilation of -figures from various American Ex- periment Stations. Water 87. i£ Butter fat 3.9^ Casein 2.9^ Albumen 5# Sugar 4.9^ Ash 7# Fibrin Trace. Galactase Trace. 100. o£ The great variations in the composition of milk are shown by the figures from Koenig, given below : PROPERTIES OF MILK 9 Maximum. Minimum. Water 9069 80.32 Fat 6.47 167 Casein 423 1-79 Albumen 1.44 - 2 5 Sugar 6.03 2. II Ash 1. 21 .35 These figures represent quite accurately the maximum and minimum composition of milk except that the maxi- mum for fat is too low. The author has known cows to yield milk testing 7.6% fat, and records show tests even higher than this. BUTTER FAT. This is the most valuable as well as the most variable constituent of milk. It constitutes about 83% of butter and is an indispensable constituent of the many kinds of whole milk cheese now found upon the market. It also measures the commercial value of milk and cream, and is used as an index of the value of milk for butter and cheese production. Physical Properties. Butter fat is suspended in milk in the form of extremely small globules numbering about 100,000,000 per drop of milk. These globules vary con- siderably in size in any given sample, some being five times as large as others. The size of the globules is affected mostly by the period of lactation. As a rule the size decreases and the number increases with the advance of the period. In strippers' milk the globules are some- times so small as to render an efficient separation of the cream and the churning of same impossible. The size of the fat globules also varies with different breeds. In the Jersey breed the diameter of the globule 10 MARKET DAIRYING is one eight-thousandth of an inch, in the Holstein one twelve-thousandth, while the average for all breeds is about one ten-thousandth. Night's milk usually has smaller globules than morn- ing's. The size of the globules also decreases with the age of the cow. The density or specific gravity of butter fat at ioo° F. is .91 and is quite constant. Its melting point varies between wide limits, the average being 92 ° F. Composition of Butter Fat. According to Richmond, butter fat has the following composition : Butyrin 3.85 ) Caproin 3 .60 I Soluble or volatile. Caprylin 55 \ Caprin 1 . 90 Laurin 7 . 40 Myristin 20.20 Palmitin 25 .70 - Stearin 1 . 80 Olein, etc 35-00 Insoluble or ;:non- volatile. This shows butter fat to be composed of no less than nine distinct fats, which are formed by the union of glycerine with the corresponding fatty acids. Thus, buty- rin is a compound of glycerine and butyric acid ; palmitin, a compound of glycerine and palmitic acid, etc. The most important of these acids are palmitic, oleic, and butyric. Palmitic acid is insoluble, melts at 144 F., and forms (with stearic acid) the basis of hard fats. Oleic acid is insoluble, melts at 57 F., and forms the basis of soft fats. PROPERTIES OF MILK 11 Butyric acid is soluble and is a liquid which solidifies at — 2° F. and melts again at 28 ° F. Insoluble Fats. A study of these fats is essential in elucidating the variability of the churning temperature of cream. As a rule this is largely determined by the relative amounts of hard and soft fats present in butter fat. Other conditions the same, the harder the fat the higher the churning temperature. Scarcely any two milks contain exactly the same relative amounts of hard and soft fats, and it is for this reason that the churning tem- perature is such a variable one. The relative amounts of hard and soft fats are influ- enced by: 1. Breeds. 2. Feeds. 3. Period of lactation. 4. Individuality of cows. The butter fat of Jerseys is harder than that of Hol- steins and, therefore, requires a relatively high churning temperature, the difference being about six degrees. Feeds have an important influence upon the character of the butter fat. Cotton seed meal and bran, for example, materially increase the percentage of hard fats. Gluten feeds and linseed meal, on the other hand, produce a soft butter fat. With the advance of the period of lactation the per- centage of hard fat increases. This chemical change, to- gether with the physical change which butter fat under- goes, makes churning difficult in the late period of lac- tation. The individuality of the cow also to a great extent influences the character of the butter fat. It is inherent 12 MARKET DAIRYING in some cows to produce a soft butter fat, in others to produce a hard butter fat, even in cows of the same breed. Soluble Fats. The soluble or volatile fats, of which butyrin is the most important, give milk and sweet cream butter their characteristic flavors. Butyrin is found only in butter fat and distinguishes this from all vegetable and other animal fats. The percentage of soluble fats decreases with the period of lactation, also with the feeding of dry feeds and those rich in protein. Succulent feeds and those rich in carbo- hydrates, according to experiments made in Holland and elsewhere, increase the percentage of soluble fats. This may partly account for the superiority of the flavor of June butter. It may be proper, also, to discuss under volatile or soluble fats those abnormal flavors that are imparted to milk, cream, and butter by weeds like garlic and wild onions, and by various feeds such as beet tops, rape, par- tially spoiled silage, etc. These flavors are undoubtedly due to abnormal volatile fats. Cows should never be fed strong flavored feeds shortly before milking. When this is done the odors are sure to be transmitted to the milk and the products therefrom. When, however, feeds of this kind are fed shortly after milking no bad effects will be noticed at the next milking. Albumenoids. These are nitrogenous compounds which give milk its high dietetic value. Casein, albumen, globulin and nuclein form the albumenoids of milk, the casein and albumen being by far the most important. Casein. This is a white colloidal substance, possessing neither taste nor smell. It is the most important tissue- forming constituent of milk and forms the basis of an almost endless variety of cheese. PROPERTIES OF MILK 13 The larger portion of the casein is suspended in milk in an extremely finely divided amorphus condition. It is intimately associated with the insoluble calcium phosphate of milk and possibly held in chemical combination with this. Its study presents many difficulties, which leaves its exact composition still undetermined. Casein is easily precipitated by means of rennet extract and dilute acids, but the resulting precipitates are not identically the same. It is not coagulated by heat. Albumen. In composition albumen very closely re- sembles casein, differing from this only in not containing sulphur. It is soluble and unaffected by rennet, which causes most of it to pass into the whey in the manufacture of cheese. It is coagulated at a temperature of 170 F. It is in their behavior toward heat and rennet that casein and albumen radically differ. Milk Sugar. This sugar, commonly called lactose, has the same chemical composition as cane sugar, differing from it chiefly in possessing only a faint sweetish taste. It readily changes into lactic acid when acted upon by the lactic acid bacteria. This causes the ordinary phenom- enon of milk souring. The maximum amount of acid in milk rarely exceeds .9%, the germs usually being checked or killed before this amount is formed. There is there- fore always a large portion of the sugar left in sour milk. All of the milk sugar is in solution. Ash. Most of the ash of milk exists in solution. It is composed of lime, magnesia, potash, soda, phosphoric acid, chlorine, and iron, the soluble lime being the most important constituent. It is upon this that the action of rennet extract is dependent. For when milk is heated to high temperatures the soluble lime is rendered insoluble and rennet will no longer curdle milk. It seems also that 14 MARKET DAIRYING the viscosity of milk and' cream is largely due to soluble lime salts. Cream heated to high temperatures loses its viscosity to such an extent that it can not be made to "whip." Treatment with soluble lime restores its orig- inal viscosity. The ash is the least variable constituent of milk. Colostrum Milk. This, is the first milk drawn after parturition. It is characterized by its peculiar odor, yel- low color, broken down cells, and high content of albu- men which gives it its viscous, slimy appearance and causes it to coagulate on application of heat. According to Eugling the average composition of colos- trum milk is as follows : Water 71.69* Fat 3-37 Casein 4.83 Albumen 15.85 Sugar 2.48 Ash 1.78 The secretion of colostrum milk is of very short dura- tion. Usually within four or five days after calving it assumes all the properties of normal milk. In some cases, however, it does not become normal till the sixth or even the tenth day, depending largely upon the condition of the animal. A good criterion in the detection of colostrum milk is its peculiar color, odor, and slimy appearance. The dis- appearance of these characteristics determines its fitness for butter production. Milk Secretion. Just how all of the different con- stituents of milk are secreted is not yet definitely understood. But it is known that the secretion takes PROPERTIES OF MILK 15 place in the udder of the cow, and principally during the process of milking. "Further, the entire process of milk elaboration seems to be under the control of the nervous system of the cow. This accounts for the changes in flow and richness of milk whenever cows are subjected to abnormal treatment. It is well known that a change of milkers, the use of rough language, or the abuse of cows with dogs and milk stools, seriously affects the production of milk and butter fat. It is therefore of the greatest practical importance to milk producers to treat cows as gently as possible, especially during the process of milking. How Secreted. The source from which the milk con- stituents are elaborated is the blood. It must not be sup- posed, however, that all the different constituents already exist in the blood in the form in which we find them in milk, for the blood is practically free from fat, casein, and milk sugar. These substances must then be formed in the cells of the udder from material supplied them by the blood. Thus there are in the udder cells that have the power of secreting fat in a manner similar to that by which the gastric juice is secreted in the stomach. Simi- larly, the formation of lactose is the result of the action of another set of cells whose function is to produce lac- tose. It is believed that the casein is formed from the albumen through the activity of certain other cells. The water, albumen, and soluble ash probably pass directly from the blood into the milk ducts by the process -known as osmosis. Variations in the Quality of Milk. Milk from dif- ferent sources may vary considerably in composition, particularly in the percentage of butter fat. Even the 16 MARKET DAIRYING milk from the same cow may vary a great deal in compo- sition. The causes of these variations may be assigned to two sets of conditions : I. — Those natural to the cow. II. — Those of an artificial nature. I. QUAUTY OF MIUC AS AFFECTED BY NATURAL CONDI- TIONS. I. The composition of the milk of all cows undergoes a change with the advance of the period of lactation. During the first five months the composition remains prac- tically the same. After this, however, the milk becomes gradually richer until the cow "dries up." The following figures from Van Slyke illustrate this change: Month of Per cent of fat lactation. in milk. i 4 2 4 3 4 4 4 5 4 6 4 7 4 8 4 9 4 io 5 It will be noticed from these figures that the milk actually decreases somewhat in richness during the first three months of the period. But just before the cow dries up, it may test as high as 8%. 2. The quality of milk also differs with different breeds. Yet breed differences are less marked than those of the individual cows of any particular breed. Some breeds produce rich milk, others relatively poor PROPERTIES OP MILK 17 milk. The following data obtained at the New Jersey- Experiment Station illustrates these differences: Breed. Total Solids. Fat. Milk Sugar. Proteids. Ash. Ayshire Guernsey Holstein Tersey Per cent. 12.70 14.48 •12.12 14.34 Per cent. 3.68 5.02 3.51 4.78 Per cent. 4.84 4.80 4.69 4.85 Per cent. 3.48 3.92 3.28 3.96 Per cent. .69 .75 .64 .75 3. Extremes in the composition of milk are usually to be ascribed to the individuality or "make up" of the cow. It is inherent in some cows to produce rich milk, in others to produce poor milk. In other words, Nature has made every cow to produce milk of a given richness, which can not be perceptibly changed except by careful selection and breeding for a number of generations. II. QUAUTY OF MILK AS AFFECTED BY ARTIFICIAL CON- DITIONS. 1. When cows are only partially milked they yield poorer milk than when milked clean. This is largely explained by the fact that the first drawn milk is always poorer in fat than that drawn last. Fore milk may test as low as .8%, while the stoppings sometimes test as high as 14%. 2. Fast milking increases both the quality and the quantity of the milk. It is for this reason that fast milkers are so much preferred to slow ones. 18 MARKET DAIRYING 3. The richness of milk is also influenced by the length of time that elapses between the milkings. In general, the shorter the time between the milkings the richer the milk. This, no doubt, in a large measure accounts for the differences we often find in the richness of morning's and night's milk. Sometimes the morning's milk is the richer, at other times the evening's, depending largely upon the time of day the cows are milked. Milk can not, however, be permanently enriched by milking three times instead of twice a day. 4. Unusual excitement of any kind reduces the quality of milk. The person who abuses cows by dogs, milk stools, or boisterousness, pays dearly for it in a reduction oi both the quality and the quantity of milk produced. 5. Starvation also seriously affects both the quality and the quantity of milk. It has been repeatedly shown, in this country and in Europe, that under-feeding to any great extent results in the production of milk poor in fat. 6. Sudden changes of feed may slightly affect the richness of milk, but only temporarily. So long as cows are fed a full ration, it is not possible to change the richness of milk permanently, no matter what the character of feed composing the ration. 7. Irregularities of feeding and milking, exposure to heat, cold, rain, and flies, tend to reduce both the quantity and the quality of milk produced. PROPERTIES OF MILK 19 a RMmmllk. b. Milk. •• °0° :^roo^g*v ° ^° o°nS> o0 O. o °p< o°o CMJfY\-Mr447# Fig. 11.— Skim-milk bottle. D. Skim=milk Bottle. This bottle, shown in Fig. ii, is provided with a double neck, a large one to admit the milk, and a smaller graduated neck for fat reading. The entire scale reads one-half per cent. Being divided into ten subdivisions each subdivision reads .05%. The same bottle is also used for testing buttermilk. 52 » I ■it I \ Fig. 12. —Pi pette. MARKET DAIRYING Fig. 14.- Acid meas- ure. E. Pipette. This holds 17.6 c.c, as shown in Fig. 12. Since about .1 c.c. of milk will adhere to the inside of the pipette it is ex- pected to deliver only 17.5 c.c, which is equiva- lent to 18 grams of normal milk. F. Acid Measures. In making a Babcock test equal quantities, by volume, of acid and milk are used. The acid measure, shown in Fig. 13, holds 17.5 c.c. of acid, the amount needed for one test. The one shown in Fig. 14 is divided into six divisions, each of which holds 17.5 c.c. or one charge of acid. Where THE BABCOCK TEST 53 many tests are made a graduate of this kind saves time in filling, but should be made to hold twenty-five charges. H. A cream scaies is shown in Fig. 15. Also see Figs. 27 and 28, pages 71 and 72. Acid. The acid used in the test is commercial sul- Fig. 15— Cream scales. phuric acid having a specific gravity of 1.82 to 1.83. When the specific gravity of the acid falls below 1.82 the milk solids are not properly burned and particles of curd may appear in the fat. On the other hand, an acid with a specific gravity above 1.83 has a tendency to blacken or char the fat. The sulphuric acid, besides burning the solids not fat, facilitates the separation of the fat by raising the specific gravity of the medium in which it floats. Sulphuric acid must be kept in glass bot- tles provided with glass stoppers. Exposure to the air materially weakens it. Making a Babcock Test. The different indicated as follows : 1. Thoroughly mix the sample. 2. Immediately after mixing insert the pipette into the milk and suck until the milk has gone above the mark on the pipette, then quickly place the fore finger over the Fig. 16. -Show- ing manner of emptying pi- petle. steps are 54 MARKET DAIRYING top and allow the milk to run down to the mark by slowly relieving the pressure of the ringer. 3. Empty the milk into the bottle in the manner shown in Fig. 16. 4. Add the acid in the same manner in which the milk was emptied into the bottle. 5. Mix the acid with the milk by giving the bottle a slow rotary motion. 6. Allow mixture to stand a few minutes. 7. Shake or mix again and then place the bottle in the tester. 8. Run tester four minutes at the proper speed. 9. Add moderately hot water until contents come to the neck of the bottle. 10. Whirl one minute. 11. Add moderately hot water un- til contents of the bottle reach about the 8% mark. 12. Whirl one minute. 13. Read test. £ How to. Read Milk Test. At the top of the fat column is usually quite a pronounced meniscus as shown in Fig. 17. A less pronounced one is found at the bottom of the column. The fat should be read from the extremes of the fat column, 1 to 3, not from 2 to 4, when its temperature is about 140 F. Too high a temperature gives too high •8 Fie:. 17.— Fat column sho w ing meniscuses. THE BABCOCK TEST 55 a reading, because of the expanded condition of the fat, while too low a temperature gives an uncertain reading. MM ■ m Fig. 19.— Milk bot- tle tester. I. Be sure you have Fig. 18. Burette method. Precautions in Making a Test a fair sample. 2. The temperature of the milk should be about 6o or jo degrees. 3. Always mix twice after acid has been added. 4. Be sure your tester runs at the right speed. 56 MARKET DAIRYING 5. Use nothing but clean, soft water in filling- the bottles. 6. Be sure the tester does not jar. 7. Be sure the acid is of the right strength. 8. Mix as soon as acid is added to milk. 9. Do not allow the bottles to become cold before reading the test. 10. Read the test twice to insure a correct reading. The water added to the test bottles after they have been whirled should be clean and pure. Water containing much lime seriously affects the test. Such water may be used, however, when first treated with a few drops of sulphuric acid. As stated before skim-milk, buttermilk and cream are tested in the same way as milk, with the exception that the cream sample is weighed not measured. Cleaning Test Bottles. As soon as the test is read, the bottles are emptied by shaking them up and down so as to remove the white sediment. Next wash them in hot water containing some alkali, and finally rinse them with hot water. Occasionally the bottles should be rinsed with a special cleaning solution, which is made by dis- solving about one ounce of potassium bichromate in one pint of sulphuric acid. A small brush should also oc- casionally be run up and down the neck of the bottle. Testing or Calibrating Milk Bottles. Fill the bottle to the zero mark with water, or preferably wood alco- hol to which a little coloring matter has been added. Immerse the lower section of the tester, shown in Fig. 19, in the contents of the bottle. If the bottle is correct, the contents will rise to the 5% mark. Next immerse both sections of the tester which will bring the contents to the 10% mark if the bottle is correctly calibrated. THE BABCOCK TEST 57 It has been learned that the volume of the graduated part of the neck is 2 c.c. Each section of the tester is made to displace 1 c.c. when immersed in the liquid, hence the two sections will just fill the scale if the latter is correct. The method recommended below for calibrating cream bottles may also be used with milk bottles. Calibrating Cream Bottles. According to Hunziker,* the most satisfactory method of calibrating cream test bottles is as follows (see Fig. 18) : Fill the bottle to the zero mark with water. Remove any drops adhering to the inside of the neck with a coiled piece of filter or blotting paper. Now slowly add measured amounts of water from an accurate burette graduated to at least 0.1 c.c. Every 0.1 c.c. of water run into the neck is equiv- alent to 0.5% on the scale of an 18 gram cream bottle and 1.0% on a 9 gram cream bottle. That is, with an 18 gram 30% bottle, 6 c.c. of water would be required to exactly fill the scale on the neck. In calibrating milk and cream bottles, different parts of the neck should be tested as well as the neck as a whole. Calculating Speed of Tester. The speed at which a tester must be run is dependent upon the diameter of the wheel carrying the bottles. The larger this wheel the fewer the revolutions it must make per minute to effect a complete separation of the fat. In the following table by Farrington and Woll the necessary speed per given diameter is calculated: ♦Bulletin No. 145, Indiana Experiment Station. 58 MARKET DAIRYING Fig. 20.— Steam Babcock Tester. Testing Cream. The testing of cream is explained in detail in Chapter VII. CHAPTER VI. COMPOSITE SAMPLING. Where milk is bought on the fat basis, it is essential that it be sampled daily as it arrives at the creamery. It is not practicable, however, to make daily tests of the samples because this would involve too much work. Each patron is therefore provided with a pint jar to which samples of his milk are added daily for one or two weeks, the sample thus secured being called a composite sample. A test of this composite sample represents the average percentage of butter fat in the milk for the period during which the sample was gathered. Careful experiments have shown that quite as accurate results can be obtained with the composite method of testing as is possible by daily tests, besides saving a great deal of work. This has lead to its universal adoption wherever milk is bought by the Babcock test. All composite jars should be carefully labeled by plac- ing numbers upon them. These numbers should be writ- ten in large indelible figures as exhibited by the composite jar shown in Fig. 24. Shelves are provided in the intake upon which the jars are arranged in regular consecutive order. Numbers corresponding to those on the jars are placed on the milk sheet opposite the names of the patrons which should be arranged alphabetically. Taking the Samples. Whatever the method of sam- pling, all milk should be sampled immediately after it enters the weigh can, not, as is frequently the case, after it is weighed. 59 60 MARKET DAIRYING Most of the sampling is done by either of two methods: (i) by means of a half ounce dipper, shown in Fig. 21, or (2) by means of long narrow tubes, one of which is shown in Fig. 22. The dipper furnishes a simple and easy means of sampling milk. Where the milk is thoroughly mixed, and the variations in quantity from day to day are slight, the dipper method of sampling is accurate. The other method of sampling is illustrated by the Scovell sampler (Fig. 23). The main tube of the sampler is open at both ends, the lower of which closely fits into a cap provided with three elliptical openings. As the sampler is lowered into the milk the latter rushes through the openings filling the tube to the height of the milk in the can. When the cap strikes the bottom of the can the tube slides over the openings, thus permitting the sample to be withdrawn and emptied into the composite jar. This sampler has the advantage of always taking an aliquot portion of the milk, and furnishing an accurate sample when the sampling is somewhat delayed, because it takes as much milk from the top as it does from the bottom of the can. The McKay sampler (see page 66) works on the same principle as the Scovell and has proven very satisfactory. Preservatives. Milk cannot be satisfactorily tested after it has loppered owing to the difficulty of securing an accurate sample. This makes it necessary to add some preservative to the composite samples to keep them sweet. The best preservatives for this purpose are corrosive sublimate, formalin, and bichromate of potash. All of these are poisons and care must be taken to place them COMPOSITE SAMPLING 61 Fig. 22.— Fig. 23 •— Milk tWef. Scovell Fig. 21.— Milk sampling sampler. tube. where children, and others unfamiliar with their poison- ous properties, can not have access to them. The bichromate of potash and corrosive sublimate can be purchased in tablet form, each tablet containing enough preservative to keep a pint of milk sweet for about two 62 MARKET DAIRYING weeks. The tablets color the milk so that there can be no mistake about its unfitness for consumption. When colorless preservatives are used, like ordinary formalin and corrosive sublimate, a little analine dye should be added to prevent mistaking the identity of milk treated with these preservatives. During the warm summer time the bichromate of potash is not as satisfactory as either of the other two preservatives mentioned, because of its comparative weak- ness and liability to interfere with the test when too much of it is used. When the bichromate is used in the ordi- nary solid form not more than a piece the size of a pea should be used, otherwise a good, clear test is not possible. For spring, fall, and winter use, however, bichromate of potash is excelled by no other preservative, either in cheapness, or safety and convenience in handling. Care of Composite Samples. It is a duty which the milk buyer owes his patrons to keep the sample jars carefully locked up in the refrigerator when not in use so as to prevent the possibility of anyone's tampering with them. This will serve the additional purpose of excluding the light and heat from the samples, for they will keep but a short time when exposed to light and heat. When the sample jars are permitted to stand a few days without shaking, the cream which rises will dry and harden, especially that in contact with the sides of the jar, so that it becomes difficult to secure a fair sample on testing day without special treatment of the sample. This is prevented by giving the jar a rotary motion every time a sample of milk is added. It is important, too, that the covers of the jars fit tight, otherwise evaporation takes place, resulting in an in- creased test. In several instances the author has ob- COMPOSITE SAMPLING 63 served that the sampler did not cover the jars at all ! Can we wonder why patrons complain so frequently about the testing? Where the jars are kept uncovered for sev- eral weeks the cream is in a condition in which it can not be reincorporated with the milk and the Babcock test in this case becomes truly a snare and delusion. Should the samples show any dried or churned cream on testing day, the sample jars must be placed in water at a temperature of no° F. for five or ten minutes to allow the cream or butter to melt. When this is done the sample for the test bottle must be taken instantly after mixing, as the melted fat separates very quickly. Frequency of Testing. It must not be supposed that if enough preservative can be added to the sample jars to keep the milk sweet for a month or longer that it is just as well to make monthly tests as weekly. Far from it. Even if the milk does remain sweet, the tendency of the cream to churn and become dried and crusty is in itself sufficient protest against monthly testing. It is rare, indeed, that samples that have been kept for a month or longer can be sampled satisfactorily without warming them in a water bath, which means a great deal of extra work. The best tests are secured when the samples are tested weekly or at most every two weeks. When the tests are made weekly it rarely becomes necessary to warm the samples if they have been properly cared for. Then, too, if an error is made anywhere in the testing, there are three other tests for the month that help to mini- mize it. It is not strange at all that a sample jar should break occasionally. If the jar should contain a whole month's milk the patron is deprived of his test for 64 MARKET DAIRYING that month. On the weekly basis of testing there would still be three tests to fall back on. Composite Cream Samples. When cream is received in good condition, the method of composite sampling may be employed in the same manner as with milk. The best results are always obtained, however, by testing each delivery of cream, and this practice is strongly recommended. Only samplers which take samples pro- portional to the amount of cream, are permissible in mak- ing composite samples of cream. Fig. 24.— Composite test jar. Glass top composite jar. CHAPTER VII. SAMPLING AND TESTING CREAM. CREAM SAMPLING AND SAMPLERS. Taking an Aliquot Sample. This means that the amount of cream taken for the composite test jar, must always be proportional to the amount of cream furnished. If cream always had the same richness, or if always the same amount were furnished, the dipper method of sampling would give satisfactory results, provided the cream was thoroughly mixed before sampling. But since we rarely find two batches of cream alike, either in quan- tity or quality, the necessity of taking an aliquot sample becomes apparent. This may be made perfectly plain by the following illustration : Feb. i patron X furnishes 50 lbs. of 20% cream. Feb. 2 patron X furnishes 30 lbs. of 30% cream. Feb. 3 patron X furnishes 20 lbs. of 40% cream. Dividing the 'total butterfat furnished during the three days by the total pounds of cream we get 27, which repre- sents the correct average test. This test would be secured by taking aliquot samples. The test by the dipper method would equal the sum of the three tests divided by three. Thus 20-}-30+4CK-3=30, the average test by the dipper method, differing from the correct average test by 3%. By the dipper method the same amount of cream is taken for a sample, regardless of the amount of cream fur- nished. 65 66 MARKET DAIRYING Cream Samplers. While an aliquot sample is neces- sary only where composite samples are made, samplers taking an aliquot sample, like the Scovell, McKay and Michels, have the further advantage of securing a more accurate sample when the cream is not thoroughly mixed. These samplers take a uniform" sample from the top to the bottom of the cream in the can. The "milk thief," which also takes an aliquot sample, does not take as satis- factory a sample when the cream is not thoroughly mixed. Q ±? fes^ a^ Fig. 25.— Michels sampler. Fig. 26.— McKay sampler. McKay Sampler. This consists of two tubes, one of which slides into the other. One side of each tube is open so that the cream enters along the entire side of the SAMPLING AND TESTING CREAM 67 sampler. When the sampler is filled the tubes are turned with the openings qr slots at right angles to each other, thus closing the sampler and permitting the withdrawal of the sample of cream. See Fig. 26. Michels Sampler. This consists of a modified Scovell sampler heated in a tin heater as shown in Fig. 25. A is a steam and hot water reservoir with an inlet at B. The steam and hot water discharge through a circle of small openings at D. The condensed steam finds exit at C. £ is a Scovell sampler provided with a handle, G, and a circular piece of heavy tin, K, which holds the sampler in position and prevents the escape of steam. F is a strong wire attached to the cap which opens and closes the sampler. The wire ends at the top in a right angle turn, H, which rests across the top of the sampler when the latter is open. The construction of the heater prevents the entrance of water into the sampler and neces- sitates the use of but a very small amount of steam, which is admitted through the steam hose, /. The latter con- nects with the pipe, /, leading to the boiler. When ready to sample, remove the sampler from the heater, plunge at once to the bottom of the can of cream to be sampled, and remove quickly. While holding the composite sample jar in the left hand, discharge the con- tents of the sampler into it by pressing down on H with the thumb of the hand holding the sampler. Owing to the heated condition of the sampler, the cream discharges instantly and, what is equally important, all of it dis- charges. The sampler is accurate, quick, convenient and simple, and makes the sampling of heavy, rich cream, or thick, sour cream, no more difficult than that of milk. 68 MARKET DAIRYING The McKay sampler can also be heated in the tin heater and is probably to be preferred to the modified Scovell sample for sampling extremely cold or extremely rich cream. Scovell Sampler and Milk Thief. These samplers are illustrated and described on page 61. SAMPLING AND WEIGHING AT THE) FARM. In addition to< the regular supply of empty, sterile cream cans, the cream gatherer should be provided with a pair of scales, a cream pail, tubes or jars for carrying the cream samples, a Gream stirrer and a sampling tube or a small sample dipper. The dipper may be used when the samples are tested after each delivery. Where com- posite samples are taken the sampling tube must be used owing to the daily variation in the quantity and quality of cream. Thoroughly mix the cream before taking the sample. This is best accomplished by pouring it several times from one vessel to another. If the cream is lumpy, the lumps should be broken up with the stirrer. Immediately after mixing the cream, a sample is taken and placed in the patron's sample tube or jar. The receptacle should be plainly numbered and provided with a tight-fitting cover. The cream is then weighed and poured into the regular supply cans. The samples should be carefully placed in a carrying case where they are protected from breakage and outside temperatures. Promptly on arrival at the creamery the samples are emptied into their respective composite sample jars, if the composite method of testing is followed. Where the cream is too thick for satisfactory sampling SAMPLING AND TESTING CREAM 69 with the sampling tubes, a proportionate amount of cream may be measured by putting into a graduated tube, with a dipper, say one c.c. of cream for every pound of cream furnished. SAMPLING AND WEIGHING AT THE CREAMERY. There are several methods of weighing and sampling in vogue at the present time. One is to sample and weigh the cream in the cans in which it is delivered. In this case the sample is taken with a dipper or sampling tube after the cream has been thoroughly mixed with a stirrer. The cream is then weighed and emptied directly into the cream vat or into a receiving can. From the latter it may be conducted into the cream vat by gravity or by means of a pump. A better method of handling the cream is to pour it from one can to another several times before sampling. This insures better mixing than is pos- sible with the stirrer alone. But even where the cream is poured, the stirrer may be of value in supplementing the mixing, especially in case the cream is lumpy. Weigh the cream in the delivery can or the receiving can and run it by gravity into the cream vat. In case composite samples are made, an aliquot portion of cream must be taken by means of one of the sampling tubes. And where the cream is not thoroughly mixed be- fore sampling, the Scovell, McKay, or Michels sampler is preferred. All cream samplers except the Michels must be rinsed in hot water after each sampling. This is especially im- portant when sampling heavy cream. Where the cream is weighed in the cans, the weight of the empty can should be permanently marked upon it. 70 MARKET DAIRYING TESTING CREAM. Frequency of Testing. Where the cream is delivered to the creamery in good condition, composite samples may- be taken in the same manner as with milk. Usually, how- ever, where a great deal of hand separator cream is handled, some of it is delivered in too bad condition for composite sampling. In this case it becomes necessary to test the cream as often as it is delivered. At present in many of the larger and in some of the smaller creameries, a test is made of each delivery of cream. This practice insures the most satisfactory tests, but requires more work than where composite samples are taken. On this account a great deal of cream is still tested by the latter method. Where composite samples are made, these are preferably tested once a week and should never be tested less than twice a month. See chapter on "Composite Sampling.'' Necessity of Weighing Cream. Accurate tests of cream can not be secured by measuring the sample into the bottle as is done in the case of milk. The reason for this is that the weight of cream varies with its richness. The richer the cream the less it weighs per unit volume. This is illustrated in the following table by Farrington and Woll; SAMPLING AND TESTING CREAM 71 Weight of fresh separator cream delivered by a 17.6 c.c. pipette. Percent of fat Specific gravity in cream. (weighed.) 10 1.023 15 1.012 20 1.008 25 1.002 30 .996 35 .980 40 .966 45 .950 60 .947 Weight of cream in grams. 17.9 17.7 17.3 17.2 17.0 16.4 16.3 16.2 15.8 These figures plainly show that justice can not be done to patrons where cream is sampled with a 17.6 c.c. pipette. Cream is therefore always weighed on a cream scales, the amount necessary for a full sample being eighteen grams. Cream Bottles and Their Uses. Numerous styles of cream bottles are now upon the market. They range in length from six to nine inches with necks graduated from 30 to 55%. The nine-inch bottles are graduated from 50 to 55% and re- quire special testers on account of their unusual length. These long- Fig. 27.-Torsion cream scales. necked bottles have the advantage of permitting the use of a full sample of cream which insures a more accurate reading than is pos- sible where only half a sample of cream is put in an 72 MARKET DAIRYING ordinary cream bottle, or where shorter wide-mouthed 50% bottles are used. Fig. 28.— Cream scales. A cream bottle commonly used is the Winton 30% qgjp bottle, shown in Fig. 10. With this bottle only- half a sample (9 grams) of rich cream can be used. To the half sample of cream a scant half-measure of acid is added, and the testing finished in the usual way. What is better, however, is to add to the nine grams of cream approximately 9 c.c. of water and then use the full amount of acid. Obviously where only half a sample of cream is used in the ordinary bottle, the test must be multiplied by 2 to get the correct reading. Lately, a small bore cream bottle (Fig. 29) has been placed upon the market in which only half a sample of cream is used, but which gives a reading for a full sample. This does away Pig. 29— Nine with multiplying tests by 2 when only half a gram cream bottle. SAMPLING AND TESTING CREAM 73 sample is used, and reduces the error in reading by one- half. The small bore of the neck also lessens any error in reading the test. In testing cream with this bottle, add 9 grams of cream, 9 c.c. of water, 17.6 c.c. of sulphuric acid and proceed with the test in the usual way, remembering that the fat column gives the reading for an 18 gram sample. Preparing the Sample. Before weighing the cream on the balance, care should be taken to thoroughly mix the sample by pouring and repouring a few times. Should the samples show any dried or churned cream, the sample jars must be placed in water at a temperature of about no° F. until the lumps of cream or butter have melted. When this is done the sample for the test bottle must be taken instantly after mixing, as the melted fat separates very quickly. In general, warming the sample jars some- what before sampling by placing them in warm water will facilitate the mixing and sampling of the cream. Making and Reading Cream Tests. The different steps in testing cream are essentially the same as in testing milk. However, as already stated, the cream must be weighed and tested in a special bottle. Furthermore, special precautions must be used in reading the test. It is well known that reading the extremes of the fat column gives too high a reading. This error is due to the meniscus at the top of the fat column the size of which varies with the width of the neck. Farrington and Woll recommend reading from the lowest extremity of the fat column to the bottom of the upper meniscus. This is the method commonly employed in reading tests. Eckles and Wayman recommend removing the meniscus by adding a small quantity of amyl alcohol (colored red) 74 MARKET DAIRYING to the top of the fat column. Farrington suggests add- ing a few drops of fat-saturated alcohol to the top of the fat as a means of removing the meniscus. Ordinary alcohol has a solvent action on butter fat, hence the neces- sity of using fat-saturated alcohol. Hunziker* after a thorough investigation of the sub- ject, has found "glymol" best suited for the removal of the meniscus. Glymol is known commercially as white mineral oil and is used for typewriters, sewing machines, etc. It will give satisfactory results without the addition of coloring matter. It may be colored, however, by plac- ing a small cheese cloth bag containing "alkanet root" in a bottle of glymol for a day or two. One ounce of alkanet root will color one quart of glymol. A few drops of the glymol are sufficient, and should be carefully added to the top of the fat column before reading the test. To get accurate readings the bottles should be read while the temperature of the fat is between 135 and 140 F. The bottles should be taken from the tester and placed in a water bath having a temperature of 140 F. and kept there several minutes, or long enough to cool the fat to 140 F. The water in the vessel should extend to the extreme top of the fat in the bottles, or preferably a little above. Accurate readings cannot be obtained by reading the bottles directly from the tester; the first bottles removed have too high a temperature while those removed last have too low a temperature. ^Bulletin 145, Indiana Experiment Station. CHAPTER VIII. I. THE LACTOMETER AND ITS USE. This instrument, shown in Fig. 30, is used to determine the specific gravity of milk. The stem has two scales upon it, a thermometer scale at the upper end and a lac- tometer scale at the lower. The latter scale reads from fifteen to forty, being divided into twenty-five divisions, each of which reads one lactometer degree. The lower end of the instrument consists of two bulbs : an upper one containing the mercury for the thermometer scale, and a lower and larger one weighted with shot or mercury which serves to immerse and to keep in an upright posi- tion the large oblong bulb or float below the stem. Making the Test. In making a lactometer test the sample of milk is carefully mixed and placed in the lactometer cylinder. (Fig. 31.) The lactometer is now carefully lowered into it and enough milk is added to the cylinder to fill it brim full. Now place your eye in a hori- zontal position with the surface of the liquid and read down as far as the liquid will permit. The reading thus obtained is the correct lactometer reading, provided the temperature as indicated by the thermometer scale is 6o°. Corrections for Temperature. Lactometers are stan- dardized at a temperature of 60 ° F. ; but, since it is diffi- cult to have a sample always at this temperature, cor- rections may be made for temperatures ranging from 50 to 70 . As the temperature rises the liquid expands and the specific gravity decreases. This decrease amounts to 75 76 MARKET DAIRYING one-tenth of a lactometer degree for every degree of tem- perature above 60. A decrease in temperature would result in a corresponding increase in the specific gravity. For every degree below 60, therefore, we subtract one- tenth degree from, and for every degree above 60 we Fig. 31.— Lactom- eter cylinder. add one-tenth degree to, the lactometer reading. Ex- amples : 1. Lactometer reading is 32.5 at a temperature of 55. Corrected reading is 32.5 less .5, equals 32. 2. Lactometer reading is 31.7 at a temperature of 63. Corrected reading is 31.7 plus .3, equals 32. Interpretation of Lactometer Reading. In the chap- ter on milk we learned that normal milk has an average LACTOMETER AND ITS USE 77 specific gravity of 1.032. This means that a tank that holds just 1,000 pounds of water would hold 1,032 pounds of milk. On the lactometer scale the 1.0 is omitted. A reading of 32, expressed in terms of specific gravity, would therefore read 1.032. Precautions in Making a Lactometer Test. 1. A lactometer test should not be made until three or four hours after the milk leaves the udder of the cow. The reason for this is that milk, immediately after it is drawn, holds mechanically mixed with it air and probably other gases, which tends to give too low a reading. 2. The sample must be thoroughly mixed. If a layer of cream is allowed to form at the surface, the conse- quence is that the hollow oblong bulb will float in partially skimmed milk and give too high a reading. 3. A dirty lactometer is certain to give a false reading. A lactometer should be washed in luke warm (not hot) water to which a little soda or other alkali has been added, and then rinsed off with clean water and wiped. II. MILK SOLIDS. The solids of milk include everything but the water. If a sample of milk be kept at the boiling temperature until all the water is evaporated, the dry, solid residue that remains constitutes the solids of milk. It is con- venient to divide the solids into two classes, one inclu- ding all the fat, the other all the solids which are not fat. In referring, therefore, to the different solids of milk, we speak of the "fat" and the "solids not fat" which, to- gether, constitute the "total solids." The amount of each of these different solids present in milk is easily seen from the composition of milk. Thus, besides water, milk con- tains : 78 MARKET DAIRYING 3-9% fat 2.gfo casein 0.5^ albumen 4-0 sugar o.yfo ash = g.fo= solids not fat. Total i2.9#=total solids. Relationship of Fat and Solids not Fat. In normal milk a fairly definite relationship exists between the fat and the solids not fat. For example, milk rich in fat is likewise rich in solids not fat. On the other hand, milk poor in fat is also poor in solids not fat. As a general rule, an increase in the solids not fat always accompanies an increase in the percentage of fat. The increase is, however, not quite proportionate, the fat increasing the more rapidly. Since the casein represents the most valuable constitu- ent of the solids not fat, the following ratio between this substance and the fat very well illustrates the relation- ship that exists between the fat and solids not fat in milk: According to Van Slyke. Per cent fat. Per cent casein. 3-00 2.10 3-25 2.20 3-50 2.30 3-75 2.40 4- 00 2.50 4-25 2.60 4-5° 2.70 Specific Gravity as Affected by Richness of Milk. The richness of milk seems to have but a very slight effect on its specific gravity. Usually a four per cent milk shows a slightly higher reading than a three per LACTOMETER AND ITS USE 79 cent milk, but the specific gravity of a four per cent milk is practically the same as that of a four and one-half per cent milk. From what has been said about the relation- ship of the fat and solids not fat in milks of different richness, it is quite natural that the specific gravity of such milks should vary but little. If the fat alone were increased, the lactometer reading would naturally be de- pressed. But since the solids not fat increase in nearly the same proportion as the fat, the depression caused by the latter is compensated for by the former. Calculation of Milk Solids. The milk solids are cal- culated from the fat and the lactometer reading of milk. This is done by means of the following formula worked out at the Wisconsin Agricultural Experiment Station : Formula for solids not fat equals one-fourth L R plus one-fifth F, in which L stands for lactometer, R for reading, and F for fat. Expressed in another way, the solids not fat are obtained by adding one-fifth of the fat to one-fourth of the lactometer reading. The total solids are obtained by adding the fat to the solids not fat. Examples : i. To calculate solids not fat when the milk shows a lactometer reading of 31.6 and fat reading of 3.5. Sub- stituting these figures for the letters in the formula, one- fourth L R plus one-fifth F, we get : (Ql A Q K \. —j- plus -f-| equals (7.9 plus .7) equals 8.6 equals solids not fat. 2. The total solids in the above sample are obtained by adding the fat and solids not fat. Thus : 8.6 plus 3.5 equals 12,1 equals total solids. 80 MARKET DAIRYING III. DETECTION OF MILK ADULTERATION — WATERING AND SKIMMING. A knowledge of the methods of detecting watering and skimming of milk is in many cases of considerable value to milk dealers, even when the milk is bought on the fat basis. Where the milk is bought irrespective of its fat content, such a knowledge is simply indispensable for the welfare of the business. In normal milk ranging in fat from 3% to 5%, it is not difficult to detect a moderate amount of watering and skimming. We speak of normal milk because this means the milk from a full milking and excludes colostrum milk, milk from diseased cows and those far advanced in lacta- tion. Normal milk cannot be expected when cows are either only partially milked, diseased, or very far ad- vanced in lactation. The accuracy of determining the amount of watering and skimming becomes greater in proportion as the sam- ple represents more cows. For example, no sample of milk from a herd consisting of six or more cows has been known to average below 3% fat. For this reason any sample of milk testing below 3%, when taken from a herd, is to be looked upon with suspicion. On the other hand there are records of individual cows that show tests as low as 1.7% and as high as 8%. It is owing to these extreme. variations in the composition of milk from indi- vidual cows, that small amounts of adulteration cannot be estimated with the same degree of accuracy in such milk as in herd milk. Detection of Adulteration. The general procedure in determining whether milk has been watered or skimmed, or both, is as follows : LACTOMETER AND ITS USE 81 1. Determine the percentage of fat in the sample under consideration. 2. Determine its specific gravity. 3. From the fat and specific gravity calculate the solids not fat and total solids. 4. Compare the results obtained with the average specific gravity, per cent of fat, solids not fat and total solids given for normal cows' milk, or compare with the legal State Standard. 5. In drawing conclusions remember that a. Fat is lighter than water. b. Milk is heavier than water. c. Skimming increases the lactometer reading. d. Skimming slightly increases solids not fat. e. Skimming decreases fat and total solids. f. Watering decreases fat, solids not fat, lac- tometer reading and total solids. g. Watering and skimming decrease fat (ma- terially), solids not fat, and total solids. h. The solids not fat are less variable than the fat. i. . Skimming and watering may give a normal lactometer reading. From i it is seen that a normal lactometer reading is possible when milk is skimmed and watered in the right proportions. A lactometer reading without a Babcock test is therefore worthless. For herd milk a lactometer reading above 33.5 is posi- tive evidence of skimming when accompanied with a low percentage of fat. Herd milk showing a lactometer read- ing below 28 is considered watered. Examples of milk adulteration in which only herd milk is considered are given as follows: 82 MARKET DAIRYING I. Suspected sample shows: Normal milk shows: Lactometer reading 32 Lactometer reading 32 Fat 2.5 Fat 3.9 Solids not fat 8.5 Solids not fat 8.78 Total solids 11. o Total solids 12.68 Conclusion: Sample is watered and skimmed because (a) lactometer reading is normal and fat low; (b) solids not fat are nearly normal and total solids low. 2. Suspected sample shows: Lactometer reading 33 . 2 Fat 3.1 Solids not fat 8.92 Total solids 12 . 02 Conclusion: Sample is skimmed because lactometer reading is high and fat low. 3. Suspected sample shows: Lactometer reading shows 29 Fat 3.4 Solids not fat 7 . 93 Total solids 1 1 . 33 Conclusion : Sample is watered because everything is much below normal, which is to be expected in the case of watered milk. CHAPTER IX. ACID TESTS FOR MILK AND CREAM. Milk dealers and buttermakers who have had years of experience do not find it safe to rely upon their noses in determining the acidity of milk or the ripeness of cream for churning. They use in daily practice tests by which it is possible to determine the actual amount of acid pres- ent. The method of using these tests is based upon the simplest form of titration. Titration. This consists in neutralizing an acid with an alkali in the presence of an indicator which determines when the point of neutrality has been reached. Acids and alkalies are substances that have entirely opposite chemical properties. The acid in milk gives it its sour taste, and for our purpose, illustrates very well what we mean by an acid. Ordinary lime may be used to illustrate what we mean by an alkali. When lime is added to sour milk the acid unites with the lime forming a neutral substance which is neither alkaline nor acid. If we keep on adding lime to the milk we reach a point at which all the acid has combined with the lime. This is called the point of neutrality. The moment this point is passed is made visible to the eye by means of the indicator, (phenolphthalein) which is colorless in the presence of an acid but pink in the presence of an alkali. One drop of alkali added to milk after the acid has been neutralized will turn it pink. 83 84 MARKET DAIRYING In the tests used for milk and cream the alkali used is sodium hydroxide. This is made up of a definite strength so that the amount of acid can be calculated from the amount of alkali used. Kinds of Tests. There are two tests in general use at the present time: one devised by Prof. Manns and known as the Manns' Test; the other devised by Prof. Farrington and known as Far- rington's Alkaline Tablet Test. MANNS' TEST. The apparatus used in this test is illustrated in Fig. 32. It consists of a 50 c.c. burette, a 50 c.c. pipette, a small fun- nel, and a glass beaker with stirring rod. The alkali (not shown in the figure) can be bought ready made in gallon bottles and is labeled "neutral- izer." This alkali or neutral- Fig. 32.— Manns' acid test appa- ratus. izer is made by dissolving four grams of sodium hydroxide in enough water to make one liter solution. The solution thus formed is called a one-tenth normal solution, each cubic centimeter of which contains .004 of a gram of sodium hydroxide which will neutralize .009 of a gram of lactic acid. Making the Test. Measure 50 c.c. of cream with the pipette into the beaker, then with the same pipette add 50 c.c. of water. Now add five or six drops of indicator. Next fill the burette to the zero mark with the neutralizer ACID TESTS 85 and slowly run this from the burette into the cream, shaking the beaker after each addition of alkali. With the first few additions of alkali the pinkish color pro- duced quickly disappears. But when the point of neu- trality approaches, the color disappears very slowly and the neutralizer must be added drop by drop only. The moment the cream remains pink indicates that the acid has all been neutralized. The number of cubic centimeters of alkali added to the cream is then noted, and from this the percentage of acid is calculated according to the following formula: No. c.c. alkali X .009 Percent acid = No . cx . cream X 100. Example: What is the percentage of acidity when 30 c.c. of alkali are required to neutralize 50 c.c. of cream ? 30 x .009 inA ' M . j^-^ x 100 = .54*. From the formula it is evident that any amount of cream may be used for a test. But more accurate results are obtained by using 50 c.c. than less. Where this amount of cream is always used the formula may be con- siderably simplified. Thus, by dividing the numerator and denominator by 50, the / No. c.c. alkali X .009 \ expression I fh X 100 1 becomes (No. c.c. alkali X .009 X 2) or (No. c.c. alkali X .018). The acidity in the problem above would therefore equal 30 X .018 = .54$. HARRINGTON S ALKAUNE TABLET TEST. In the Farrington test the same alkali is used as in Manns', but in a dry tablet form in which it is more 86 MARKET DAIRYING easily handled than in the liquid form. Each tablet con- tains enough alkali to neutralize .034 gram of lactic acid. Apparatus Used for the Test. This is shown in Fig. 33 and consists of a porcelain cup, one 17.6 c.c. pipette, and a 100 c.c. rubber-stoppered graduated glass cylinder. CrL/NDETFJ. Fig. 33 — Farrington acid test apparatus. Making the Solution. The solution is made in the graduated cylinder by dissolving 5 tablets in enough water to make 97 c.c. solution. When the tablets are dis- solved, which takes from six to twelve hours, the solution should be well shaken and is then ready for use. The solution of the tablets may be hastened by placing the graduate in a reclining position as shown in the cut. Making the Test. With the pipette add 17.6 c.c. of cream to the cup, then with the same pipette add an equal amount of water. Now slowly add of the tablet solution, ACID TESTS 87 rotating the cup after each addition. As soon as a per- manent pink color appears, the graduate is read and the number of c.c. solution used will indicate the number of hundredths of one per cent of acid in the cream. Thus, if it required 50 c.c. of the tablet solution to neutralize the cream then the amount of acid would be .50%. From this it will be seen that with the Farrington test no calcu- lation of any kind is necessary. The acidity of milk may be determined in the same way as that of cream, except that the milk need not be diluted with water before adding the alkali. A Rapid Acid Test for Milk. Where milk is pasteur- ized it is often desirable to determine" approximately the acidity of each lot as it arrives at the creamery. It has been found that milk that contains more than .2% acid cannot be satisfactorily pasteurized. Farrington and Woll have devised the following rapid method for testing the acidity of milk that is to be pasteurized : Prepare a tablet solution by adding two tablets for each ounce of water. When the tablets have dissolved, take the solution into the intake. Now, as each lot is dumped into the weigh can a sample of milk is taken with a No. 10 brass cartridge shell and emptied into a teacup. With another, or the same, No. 10 shell add a measure of tablet solution to the cup. Mix the alkali and milk by giving the contents of the cup a rotary motion. If the milk remains white it contains more than .2% acid; if it is colored, there is less than .2% acid present. Where the tablet solution is prepared as above care must be taken to secure equal quantities of milk and solution for the test. 88 MARKET DAIRYING PRECAUTIONS IN MAKING ACID TESTS. i. Always thoroughly mix the cream or milk before taking a sample for a test. 2. Prepare the tablet solution and dilute the cream with water as nearly neutral as possible. Soft water is better than hard. 3. Keep the tablets dry and well bottled. 4. Keep the Manns neutralizer and the Farrington tablet solution carefully stoppered with a rubber stopper, as exposure to the air will weaken the solutions by absorb- ing carbonic acid. 5. With the Farrington tablets it is best to prepare a new solution every day. 6. Make the tests where there is plenty of light so that the first appearance of a permanent pink color can readily be noticed^ RELATION OE RICHNESS AND ACIDITY IN CREAM. In practice we find that the ripening is slower in rich than in poor cream. The reason for this is that the acid develops in the milk serum, which really should be used as the basis in measuring the degree of acidity, if this were possible. In a cream testing 25% we find that more acid must be developed to get the desired effects in cream ripening than is necessary in a 35% cream. This is so because in the 25 % cream we have the acid distributed through 75% milk serum, while in the 35% cream it is distributed through only 65% milk serum. If both the above creams show an acidity of .5%, this means that in the poor cream the .5 pound of acid is distributed through 75 pounds of serum, while in the rich ACID TESTS 89 cream it is distributed through only 65 pounds of serum, hence the latter must have the greater intensity of acidity. This may be graphically shown as follows: Poor cream. Rich cream. 25 # fat. 35% fat. 75% serum. .5% acid. 65% serum. .5% acid. In the illustrations above it is seen that the acid in the rich cream is distributed through less space than in the poor, hence the degree of acidity must be higher in tb^. rich cream. We find in practice where the same results are to be expected from the ripening process, a 25% cream must show about .6% acidity, while a 35% cream, about .5%. In bulletin No. 24 of the Washington Experiment Sta- tion, Prof. Spillman gives a table showing the required acidity for cream of different richness. CHAPTER X. CREAMING. Cause. Creaming is due to the difference in the speci- fic gravity of the fat and the milk serum. The fat being light and insoluble rises, carrying with it some of the other constituents of the milk. The result is a layer of cream at the surface. Processes of Creaming. The processes by which milk is creamed may be divided into two general classes : ( I ) That in which milk is placed in shallow pans or long narrow cans and allowed to set for about twenty-four hours, a process known as natural or gravity creaming; (2) that in which gravity is aided by subjecting the milk to centrifugal force, a process known as centrifugal creaming. The centrifugal force has the effect of increas- ing the force of gravity many thousands of times, thus causing an almost instantaneous creaming. This force is generated in the cream separator. ShalIow=Pan Method. The best results with this method are secured by straining the milk directly after milking into tin pans about twelve inches in diameter and two to four inches deep. It is then allowed to remain undisturbed at room temperature (6o° to 65 ° F.) for twenty-four to thirty-six hours, after which the cream is removed either with a nearly flat, perforated skimmer, or by allowing it to glide over the edge of the pan after it has been carefully loosened along the sides. The aver- age loss of fat in the skim milk by this method is 0.7%. 90 CREAMING 91 Deep=Cold=Setting Method. The best results with this method are secured by using a can like the Cooley illustrated in Fig. 34. This can is provided with a cover which allows it to be submerged in water. It also has a spout at the bottom by which the skim milk is gently removed, thus preventing the partial mixing of cream and skim milk incident to skimming with a conical dipper. The milk is put into the cans di- rectly after milking and cooled to as low a temperature as possible. To secure the best results with this method the water should be iced. Where this is done the skim milk will show only about 0.2% fat. It it desirable to allow the milk to set twenty-four hours before skimming, though usually the creaming is quite complete at the end of twelve or fifteen hours. Dilution or Aquatic Separators. One of the most unsatisfactory methods of creaming is the addition of water to the milk. The creaming by this method is done in variously constructed tin cans, which the manufacturers usually sell under the name of dilution or aquatic sepa- rators. Those uninformed about the genuine centrifugal separators are often lead to believe that they are buying real separators at a low cost when they are investing five, ten or fifteen dollars in one of these tin cans, which are no more entitled to the term separator than are the com- mon shallow pans. The average loss of fat with this system of creaming is about 1^2%. Fig. 34.— Cooley Can. 92 MARKET DAIRYING Centrifugal Method (Cream Separator). Dairies hav- ing four or more cows should cream their milk by the cen- trifugal method, the cream separator. The saving of but- ter fat with this method soon pays for the cost of a sep- arator. Moreover it has the additional advantages over the gravity methods of creaming in providing fresh, sweet skim milk for feeding purposes, and yielding cream of any desired richness. Efficiency of Creaming With a Separator. Under favorable conditions a separator should not leave more than .05% fat in the skim milk by the Babcock test There are a number of conditions that affect the efficiency of skimming and these must be duly considered in making a separator test. The following are some of these con- ditions : A. Speed of bowl. B. Steadiness of motion. C. Temperature of milk. D. Manner of heating milk. E. Amount of milk skimmed per hour, F. Acidity of milk. G. Viscosity of milk. H. Richness of cream. I. Stage of lactation. (Stripper's milk.) A. The greater the speed the more efficient the cream- ing, other conditions the same. It is important to see that the separator runs at full speed during the separating process. B. A separator should run as smoothly as a top. The slightest trembling will increase the loss of fat in the skim milk. Trembling of bowl may be caused by any of the following conditions: (1) loose bearings, (2) sepa- CREAMING 93 rator out of plumb, (3) dirty oil or dirty bearings, (4) unstable foundation, or (5) unbalanced bowl. C. The best skimming is not possible with any sepa- rator when the temperature falls below 60 ° F. A tem- perature of 85 ° to 98 F. is the most satisfactory for ordinary skimming. Under some conditions the cleanest skimming is obtained at temperatures above ioo° F. The reason milk separates better at the higher temperatures is that the viscosity is reduced. D. Sudden heating tends to increase the loss of fat in skim-milk. The reason for this is that the fat heats more slowly than the milk serum, which diminishes the difference between their densities. When, for example, milk is suddenly heated from near the freezing tempera- ture to 85 ° F. by applying live steam, the loss of fat in the skim-milk may be four times as great as it is under favorable conditions. E. Unduly crowding a separator increases the loss of fat in the skim-milk. On the other hand, a marked underfeeding is apt to lead to the same result. F. The higher the acidity of milk the poorer the creaming. With sour milk the loss of fat in the skim- milk becomes very great. G. Sometimes large numbers of undesirable (slimy) bacteria find entrance into milk and materially increase its viscosity. This results in very unsatisfactory creaming. Low temperatures also increase the viscosity of milk which accounts for the poor skimming at these tempera- tures. H. Most of the standard makes of separators will do satisfactory work when delivering cream of a richness of 50%. A richer cream is liable to result in a richer skim- 94 MARKET DAIRYING milk. The reason for this is that in rich cream the skim- milk is taken close to the cream line where the skim-milk is richest. I. Owing to the very small size of the fat globules in stripper's milk, such milk is more difficult to cream than that produced in the early period of lactation. Regulating Richness of Cream. The richness of cream is regulated by means of a cream screw in the sepa- rator bowl. When a rich cream is desired the screw is turned toward the center of the bowl, and for a thin cream it is turned away from the center. Advantages of Rich Cream. To separate a rich cream at the farm results in mutual benefit to pro- ducer and manufacturer. The main advantages are as fol- lows : (i) Less bulk to handle; (2) less cream to cool; (3) less transportation charges; (4) more skim-milk for the farmer; (5) better keeping quality; (6) allows more starter to be added; (7) gives better results in churn- ing, and (8) makes pasteurization easier, especially with sour cream. Best Time to Separate Milk.- The best results with a separator are obtained by running the milk through the machine immediately after milking. Saving of Butter Fat with a Separator. That the owner of four good cows can afford to invest $50.00 in a small cream separator is shown by the following: Four good cows will yield not less than 24,000 pounds of milk a year. By the common shallow pan method of creaming, the loss of butter fat will average 0.7 pound for every 100 pounds of milk. With the centrifugal sepa- rator the loss of fat will not average over 0.05 pound, hence there will be effected a saving of 0.65 pound of CREAMING 95 butter fat in each ioo pounds of milk by the use of the separator. At this rate, the total saving of butter fat an- nually on the 24,000 pounds of milk will be 156 pounds. Since each pound of butter fat will yield approximately 1 1-6 pounds of butter, 183 pounds of butter will be saved by the process, which, at 25 cents per pound, amounts to $45.75. This saving in butter fat alone will almost pay for the separator in one year. Fastening a Separator. To secure steady motion, the separator must be fastened to a solid foundation. There is nothing better in this respect than a concrete floor, with which every dairy should be provided. One of the best methods of fastening separators to con- crete floors is the use of expansion bolts. These consist of lag screws with tapering points pro- vided with malleable shields, having threads on their in- ner sides to fit the threads of the lag screws and pro- jections on their outer sides to catch and hold in holes made in the concrete. The shields expand as the lag screw is screwed in. Expansion Bolt. Heating Milk Before Separating. Milk received in a cold condition should be heated to about 85 ° F. before separating. There are two classes of heaters on the market for this purpose: those which admit the steam directly to the milk, known as direct heaters, and those 96 MARKET DAIRYING which permit the steam to enter a jacket surrounding the milk, known as indirect heaters. Only indirect heaters should be used in heating milk to the separating temperature. The two main objections to the direct heaters are : (i) the liability of contaminating the milk with impure steam, and (2) the effect of the sudden heating upon the loss of fat in the skim-milk which may be quite considerable when the milk is heated through a long range of tem- perature. It is well known that the exhaustiveness of skimming with any separator is greatly influenced by the manner in which the milk is heated. In general very sudden heating has the effect of diminishing the difference in the specific gravity between the fat and milk serum, con- sequently rendering the separation of the fat from the milk more difficult. In experiments conducted by the author it was found that in many instances where the milk was received in a partly frozen condition and suddenly heated to a sepa- rating temperature of 8o° to 85 ° F., the loss of fat in the skim-milk was from .08% to .12%. The addition of water to the milk through the con- densation of the steam is .also objectionable in heating milk with steam direct. The practice of turning steam into milk should therefore be abandoned. CHAPTER XL COLD STORAGE. An efficient cold storage is an indispensible asset in the manufacture of ice cream and in the proper handling of market milk and cream. Too many try to economize in first cost at the expense of insulation. This is false economy because money spent in securing thorough in- sulation will save enough in ice or refrigeration to pay for the extra cost in a short time. The accompanying illustration (Fig. 35) shows a method of construction which has been found very satisfactory, especially in larger plants. It will be noted that the walls, floor and ceiling are insulated with cork, which is one of the best of insulating materials. It is necessary, however, to use every pre- caution to keep the cork free from moisture. Thorough treatment of the surface with asphalt will render it prac- tically waterproof. Two thin layers of cork are pre- ferred to one thick layer because the breaking of joints prevents leakage at the edges. The inside walls and any partitions are constructed of four-inch hollow tile lined with two courses of 1^ inches of sheet cork. Anteroom. Cold air is relatively heavy and when the storage doors open directly into a large warm room the air rushes out as though it were water, causing a considerable loss of cold. Such loss can be prevented to a large extent by providing an anteroom, which is 97 98 MARKET DAIRYING simply a compartment about four feet wide and built along the front of the refrigerator. By having the anteroom doors closed when opening the refrigerator doors, little cold air will escape. SECOND STORY FLOOR i 4 inches Concrete I inch — Cement I>l inches Cork 1 1^2. inch esCo RK \\ Cement Finish- Skewer — Cem ent Mortar- Cement Mortar Asphalt — YT-JQINTS-x Cement Finish- ASPHALT: ►] \l INCH CEMENT FINISH" h o J J o r i u z <& 4 inches Concrete I y^, inches Sheet Cork I ^ i nches Sheet Cork ^Q'NT5 6 inches Cinders ^Thin Layer Concrete I u E CO Of o 111 h lll •;- tc :'i u . .'.*/.:/ o*'. • 'rV-O;-- V .1 »• t«*\\ FLOOR Fig. 3 .—Showing Cons r. ction of Cold Storage, COLD STORAGE 99 Doors i Special care should be exercised in securing tight-fitting doors with heavy flanges; they should also have the same degree of insulation as the other parts of the refrigerator. Forced Circulation of Air. To prevent dampness, mold and mustiness in cold storage rooms, circulation of air is absolutely essential. Usually a reasonable de- Fan Fig. 36.— Showing Method of Forced Circulation. gree of circulation is secured without resorting to mechanical methods of forcing, but forced circulation will produce the best results and is recommended for all large refrigerators. The refrigerating coils should be in a room separate from the cold storage as shown in the accompanying illustration (Fig. 36) which also shows the method of producing forced circulation. A fan located at the floor of the refrigerating room, forces the refrigerated air into the cold storage rooms, causing the warm air of the latter to escape through an 100 MARKET DAIRYING opening at ceiling, whence it passes over the refrigerat- ing coils. Here it becomes cooled and freed from its moisture, to be again forced into the cold storage room by means of the fan. Frequent removal of the ice accumulating on the refrigerating coils is necessary to maintain the best storage conditions. • Fig. 37.— Section Through Refrigerator Having Ice Chamber at One End. Natural Circulation. The best natural circulation is secured by having the refrigerating pipes in a room di- rectly above the cold storage. Air shafts are provided which conduct the cold air from the floor of the refriger- ating room to the floor of the cold storage room. Simi- lar shafts extend from the ceiling of the storage room to the top of the refrigerating coils. COLD STORAGE 101 Refrigerating Coils in Storage Room. Where forced circulation is not available, the usual method of cooling rooms for storage purposes is to arrange a series of direct expansion pipes at the ceiling and along the walls near the ceiling. In case the refrigerating machin- ery is not operated during the night it will be neces- sary to use a brine tank in addition to the direct expan- sion coils. The purpose of the brine tank is to store Fig. 37%— Insulated Ice House Joined to Refrigerator. From Bulletin 41, Minn. Dairy & Food Commission. cold to be drawn upon when the machinery is not running. The tank should be located near the ceiling where it will serve practically the same purpose as an overhead ice box. See page 297. Storage Rooms Cooled With Ice. In small dairy plants not provided with mechanical refrigerating ma- chinery, a refrigerator or cold storage with an ice cham- ber at one end is commonly used. The construction of the ice chamber is shown in Fig. 37. The ice chamber 102 MARKET DAIRYING is filled periodically from an adjoining ice house. A more satisfactory arrangement for refrigerating with ice is to have the ice house take the place of the ice chamber shown in Fig. 37^. This, of course, requires an ice house with the same degree of insulation as that of the refrigerator itself, because no saw dust is used in packing the ice. Connecting the refrigerator directly with the ice Fig. 38.— Ice Box for Small Dairymen. house dispenses with the handling of ice, produces bet- ter circulation and therefor results in a drier and cooler refrigerator. The increased circulation is due not so much to the larger mass of ice with which the air comes in contact as to the greater height of the ice house. Cir- culation may be reduced, if desired, by regulating or closing the opening at the ceiling by means of a slide Cold Storage for Small Dairymen. A temperature of 40 F. may be maintained in a simple ice box, con- structed as shown in Fig. 38. COLD STORAGE 103 The box consists essentially of two boxes separated by one-inch strips placed at intervals of about one foot. Double thickness of building paper is placed on both sides of the strips and tacked to the boxes. A one-inch strip, two inches wide, covers the upper space between the one-inch strips, thus making a dead-air space between the two boxes. The construction of the cover is the same as that of the bottom, with the exception that there is a flange at the front and sides of the cover. The sides, bottom and cover of the refrigerator are built of three-quarter-inch tongued and grooved lumber, five and a half inches wide. The ends are constructed of one and one-eighth-inch tongued and grooved flooring three and a half inches wide. The inside of the ice box is lined with galvanized iron. A rope provided with a heavy weight and running over an overhead pulley, makes it easy to raise and lower the cover. A drain is provided at the bottom. The cost of such an ice box, 7x2.5x2.5 feet, is approximately $30, including both labor and material. The efficiency of the ice box is materially increased by filling the one-inch space with granulated cork. CHAPTER XII. PASTEURIZATION OF MILK AND CREAM. The term pasteurization is derived from the discoverer of the process, Pasteur, an eminent French scientist, who is justly called the Father of Bacteriology. Originally this process was applied to wines to rid them of un- desirable fermentations. Pasteurization as applied to milk and cream consists in heating and cooling milk and cream in a manner which will destroy the bulk of bac- teria in them, but which will leave their chemical and physical properties unchanged as far as possible. Advantages of Pasteurization. The advantages to be derived from pasteurization vary with the conditions under which the milk is produced and the efficiency with which the work is conducted. If the milk comes from dairies where disease and uncleanliness prevail, pasteur- ization will prolong the keeping quality of the milk and also materially lessen, or entirely eliminate, the danger from disease germs. If, on the other hand, healthfulness and cleanliness receive the exacting attention which pre- vails on certified dairy farms, comparatively little is gained by subjecting milk to the pasteurizing process. Under existing conditions, thorough pasteurization of milk and cream is desirable, for several reasons : In the first place average unpasteurized market milk con- tains over 1,000,000 bacteria per c. c, and none of this can be guaranteed free from pathogenic organisms. Milk that comes nearest to being free from pathogenic and other classes of bacteria, is certified milk, but even 104 PASTEURIZATION OF MILK AND CREAM 105 this class of milk, in exceptional cases, contains disease producing bacteria. The large number of bacteria in average market milk is especially harmful to babies, because a large percent- age of the bacteria belong to the putrefactive and closely allied kinds, which in a large measure are responsible for the prevalence of diarrhea and general gastrointes- tinal troubles and, therefor, for the high mortality among infants and children. By properly pasteurizing milk, at least 95% of the general mass of bacteria may be de- stroyed, while all of the strictly pathogenic bacteria, like the typhoid and tubercle bacilli, may be entirely elim- inated. Pasteurization Growing in Popularity. Among large milk dealers, pasteurization has long been popular, partly because of the protection it has afforded them against spreading disease among their customers, but chiefly because of the material increase in the keeping quality of the milk resulting from this treatment. Until recently, however, consumers and health authori- ties have been divided as to the advisability of pasteur- izing milk for city trade. This attitude on the part of consumers and health authorities has largely been due to faulty methods and slipshod work which have been so characteristic of much of the pasteurizing work in the past. At present there is unmistakable evidence that pas- teurization of milk and cream for city trade is rapidly gaining favor, both among health authorities and the public in general. Two reasons may be given for the change in attitude toward pasteurization: First, the realization that no positive assurance can be given that raw milk is free from pathogenic bacteria ; secondly, the 106 MARKET DAIRYING increased confidence of the public in the efficiency of the pasteurizing process, resulting from the gradual elimina- tion of the continuous or flash process and the substitu- tion therefor of what is known as the ''holding" or "held" process, by which the milk is kept at a tempera- ture of about 145 ° F. for 30 minutes or longer. With the continued increase in the efficiency of pas- teurizing methods, pasteurization of milk and cream for city trade is bound to increase in popularity. Processes of Pasteurization -. There are two proc- esses of pasteurizing milk and cream: (1) the "con- tinuous" or "flash" process by which the milk is per- mitted to pass in continuous stream through the pasteur- izer and is subjected, on an average, less than one minute to the pasteurizing temperature; (2) the "held" or "holding" process by which every particle of milk is heated from ten to sixty minutes according to the degree of heat employed. Obviously where milk is heated only a minute, a higher temperature must be employed than where the time of exposure is longer. With the "flash" method the tem- perature varies from 165 to 180 F. and the time of exposure averages less than one minute. In case of the "held" process, the temperature ranges from 140 to 150 F. and the time of exposure from ten to sixty minutes. Low temperatures must be maintained for a longer time than high temperatures to accomplish the same result. The temperature and time of exposure should always be such as to insure the destruction of the tubercle bacillus, which is one of the most resistant of the disease bacteria most commonly found in milk. Objections to the Flash Process/ With the flash process reasonably satisfactory results in destroying bac- PASTEURIZATION OF MILK AND CREAM 107 teria cannot be obtained unless the milk is heated to 176 F. But a stream of milk coming from a flash machine and showing a temperature of 176 F., does not necessarily mean that every particle of the milk is heated to this temperature; indeed, quite the contrary is to be expected. It is easily conceivable that where milk passes through a machine in a constant stream, some particles 176 10' 20' 30 40 50 60 Fig. 39.— Chart by Dr. North. will be heated higher than others, that is, some particles will exceed 176 while others will fall short of this tem- perature. It is generally conceded that perfectly uniform heating is practically impossible with the flash process, and for this reason it is perfectly possible for some bacteria with a thermal death point of 176 F., or even lower, to escape destruction by this process. 108 MARKET DAIRYING In addition to the lack of uniform heating, the flash or continuous process has several other drawbacks, due to the relatively high temperature necessary to destroy the bacteria: (i) it materially interferes with the rising of the cream and therefore tends to destroy what is known as the "cream line;" (2) it tends to give milk a cooked taste; and (3) it tends to impair the digestibility of milk. In substantiation of the charges against the flash process, attention is called to the chart (Fig. 39) pre- pared by Dr. Chas. E. North of the New York City health department. In this chart the figures at the bottom represent min- utes, while those at the side represent degrees Fahren- heit. Starting at the top, there is a wavy line marked "salts" which shows that the salts of milk are not af- fected until exposed for one minute at 176 . At lower temperatures, a longer exposure is necessary to affect the salts. The dotted line marked "taste" shows that the taste of milk is affected by keeping it at a temperature of 167 for several minutes. At 150 an exposure of 40 minutes does not affect the taste of milk. The solid line marked "albumen" indicates that this constituent of milk is affected at an exposure of 165 ° for one minute. At an exposure of 40 minutes it does not become affected, until a temperature of 147 is reached. Looking next at the broken line marked "enzymes," it is seen that these digestive ferments of milk become affected at an exposure of 174 for one minute. At 1 45 they do not become affected until an exposure of 45 minutes is reached. PASTEURIZATION OF MILK AND CREAM 109 Next is the heavy line marked with crosses, which indicates the time and temperature at which the cream line becomes affected. Thus it will be seen that one minute's exposure at 155 affects the cream line. At 145 ° the cream line does not become affected until ex- posed for 35 minutes. The balance of the chart indicates the time and tem- perature at which some of the common disease pro- ducing bacteria are destroyed. Most resistant of the disease bacteria is the tubercle bacillus whose thermal death point is shown by the heavy line marked like a railroad track. An exposure of one minute at 176 , or 20 minutes at 140 , will kill this bacillus. The typhoid bacillus is destroyed at an exposure of 150 for one minute, or 140 for ten minutes. Streptococci and the bacteria causing diphtheria are both destroyed by heating for one minute at 150 ; an exposure of 10 minutes will destroy both at less than 140 . The two parallel light lines marked "red line" and running midway between the two heavy dark lines, in- dicate the line of safety in pasteurizing milk and cream. Going much below this line will not kill the tubercle bacillus and going much above it will affect the cream line. Dr. North properly draws the conclusion from this table that a temperature of 145 ° maintained for 25 minutes is about the most ideal. Other Considerations in Pasteurization. While the foregoing chart, together with what has been said in regard to the lack of uniformity of heating, clearly con- demns the "flash" process as an unsafe and undesirable method of treating milk, there is another matter to con- sider which makes the "flash" process seem still more 110 MARKET DAIRYING undesirable as compared with the "held" process. Be- sides the disease bacteria mentioned on the chart, there are large numbers of other bacteria in milk some of which are even more difficult to destroy than the tuber- cule bacillus. These bacteria, while perhaps harmless to adults are known to have an irritating effect on the digestive system of babies and children. And because of these bacteria and as a matter of safety so far as bacteria in general are concerned, some of the leading city milk dealers have found it desirable to expose milk at 145 for an whole hour. These milk dealers have found it wise to pay less attention to the milk constituents and more to the bacteria. In the destruction of bacteria by the pasteurizing process, it is never safe to employ temperatures which closely approximate the thermal death point of those particular bacteria which it is desired to destroy. The ups and downs in the pasteurizing temperature, the in- accuracies in thermometers, and the changing conditions in the milk itself from one day to another, make it ad- visable to employ temperatures appreciably in excess of those absolutely necessary to destroy the bacteria un- der normal conditions. Milk that has been underheated is more dangerous than that which has not been heated at all. The reason for this is that inadequate heat in pasteurizing may destroy the lactic acid bacteria (which are easily killed) and by so doing actually better the conditions for the growth of the more resistant and obnoxious kinds. Lactic acid organisms are antagonistic to other classes of bacteria and are therefore a real safeguard to milk. This makes it plain that unless milk is pasteurized at a temperature which will destroy the pathogenic and non-acid bacteria PASTEURIZATION OF MILK AND CREAM \\\ as well as the acid bacteria, it is far better not to heat it at all. Pasteurization should be condemned where its only ob- ject is to keep milk sweet. Its real object should be to destroy all actively growing bacteria and especially all disease-producing organisms such as the tubercle bacillus which is among the most resistant. The "Held" Process. In view of the large amount of data bearing upon the inefficiency of the "flash" process in pasteurizing milk, the wise milk dealer will equip himself with machinery by which milk can be held at a temperature of 145 yF. for 30 minutes or longer. There is no longer any question that to render milk safe from pathogenic bacteria it is necessary to employ the held or "holding" process of pasteurization. By this process all milk can be uniformly heated and held at the proper temperature long enough to insure the de- struction of all bacteria except those in a spore condi- tion. Fortunately the common pathogenic bacteria are not spore-bearing and hence are easily destroyed by this method of pasteurization. For general arrangement of machinery for pasteur- izing milk by "held" process, see Fig. 69, page 322. New York and Chicago Pasteurizing Regulations; In order to secure greater efficiency in pasteurizing milk, a number of cities have adopted ordinances making it necessary for milk dealers to heat milk to certain mini- mum temperatures. Thus New York City imposes the following restrictions with reference to temperature and time of exposure: No less than 158 degrees F. for at least 3 minutes. No less than 155 degrees F. for at least 5 minutes. No less than 152 degrees F. for at least 10 minutes. 112 MARKET DAIRYING No less than 148 degrees F. for at least 15 minutes. No less than 145 degrees F. for at least 18 minutes. No less than 140 degrees F. for at least 20 minutes. Chicago has the following regulations : A uniform heating of 140 degrees F. maintained for 20 minutes. A uniform heating of 150 degrees F. maintained for 15 minutes. A uniform heating of 155 degrees F. maintained for 5 minutes. A uniform heating of 160 degrees F. maintained for i J / 2 minutes. A uniform heating of 165 degrees F. maintained for 1 minute. Necessity of Clean Milk for Pasteurizing. Con- trary to general public opinion, milk to be pasteurized must be especially clean to make it a safe food for babies. The reason for this is the fact that the pasteur- izing process does not destroy the bacterial spores which are always associated with unclean milk, and a large per- centage of these spores belong to the putrefactive kind. In ordinary unpasteurized milk, these spores are held in check by the rapid development of the lactic acid bac- teria, which are first to succumb in the pasteurizing process. The ordinary pathogenic bacteria are not spore-bearing but the putrefactive and many other obnoxious kinds of bacteria are spore-bearing. These putrefactive spores, which come from manure and other filth, develop rapidly in pasteurized milk kept at high temperatures. Importance of Low Holding Temperature. While filthy milk, as pointed out above, is rich in bacterial spores, there is perhaps no milk entirely free from them. PASTEURIZATION OF MILK AND CREAM 113 On an average about 2 per cent of the total bacteria found in milk are present in the spore stage in which they cannot be destroyed by the pasteurizing process; hence the necessity of holding milk at such low tempera- ture as will prevent the development of these spores into actively growing organisms. These spores, if enabled to develop sufficiently, will impart undesirable flavors to milk; and, furthermore, it is these putrefactive kinds which are responsible, too, for a great many diarrheal and gastro-intestinal troubles of children. Pasteurized milk may appear perfectly sweet to the consumer but may be actually dangerous to children if it is kept at tempera- tures which will permit a rapid development of putre- factive and other kinds of spores. To keep pasteurized milk in a good condition, its temperature should not be allowed to exceed 50 F., and much lower temperatures are desirable. Viscogen. Thorough pasteurization reduces the vis- cosity or whipping property of cream. To assist in re- storing the original viscocity, a solution of sucrate of lime is added which is known as viscogen. This solu- tion is made by adding an excess of slaked lime to three parts of sugar dissolved in five parts of water. The mixture is allowed to stand twenty-four hours, after which the clear liquid at the top is poured from the sediment and preserved in a stoppered bottle at a low temperature. Add one part viscogen to about 150 parts of cream. Never add so much as to render the cream alkaline. While viscogen is entirely harmless, it is nevertheless an adulterant and cream treated with it must be labelled so as to indicate that it has been treated with viscogen. By holding pasteurized cream at low temperatures a 114 MARKET DAIRYING sufficient length of time, its whipping property is suffi- ciently restored to make the use of viscogen unneces- sary. PASTEURIZING MILK IN BOTTLES. While the "held" process of pasteurization has been a big step in advance of the "flash" process, it does not fulfill all that is desired in ideal pasteurization. With both processes there is too much opportunity for rein- fection of the milk after it leaves the pasteurizer. The milk cooler, pipes, air, bottle caps, bottles and employes — all subject milk to possible contamination. To show the possible seriousness of such contamination, an in- stance is cited by Dr. C. E. North in which 85 cases of typhoid fever were traced to milk which had become infected through a "typhoid carrier" whose business it was to cap the bottles. It is evident that the only way to avoid reinfection is to pasteurize the milk after it has been bottled and capped, and a fairly large number of milk dealers are already pasteurizing milk in this way with very satis- factory results. Bottle Caps. To pasteurize milk in bottles, water- tight caps are necessary. Metallic caps lined with paraf- fined paper discs, are now used to a considerable ex- tent, not only where milk is pasteurized in bottles but for ordinary handling of milk as well. These caps are similar to those used on beer bottles and are fastened in a similar manner, thus sealing the bottles against en- trance of air and water as well as against possible tampering with the contents. Special bottles and machin- ery for applying the caps are now available everywhere. Pasteurizing Apparatus. The practicability of pas- PASTEURIZATION OF MILK AND CREAM 115 teurizing bottled milk on a commercial scale is shown by Dr. C. E. North in Medical Record for July 15, 191 1. Dr. North has found that the apparatus used by brewers in pasteurizing bottled beer, can be adapted to pasteur- izing milk in bottles with satisfactory results. The re- sults obtained by him in pasteurizing milk for thirty minutes at a temperature of 148 F. in a beer pasteur- izer, are shown in the following paragraphs : "Raw milk, bacteria per cubic centimeter in the several samples, 250,000; 450,000; 200,000; 900,000; 70,000. Pasteurized top layer, bacteria per cubic centimeter, 500 ; 100 ; 300 ; 2,100 ; 500 ; 600 ; 100 ; 500 ; 200 ; 400 ; 200 ; 200. Pasteurized second layer, bacteria per cubic centimeter, 1,000; 400; 200; 600; 1,000; o; 100; 200; 100; 200; o; 400. Pasteurized third layer, bacteria per cubic centimeter, 800 ; 2,500 ; 400 ; 200 ; 300 ; 600 ; 300 ; 500 ; 300. Pasteurized fourth layer, bacteria per cubic centimeter, 600; 400; 600; 300; 1,800; 400; 300; 600; 400; 300; 100." Commenting on the low bacterial counts obtained in these experiments, Dr. North says: "I have never be- fore obtained from any pasteurizing apparatus of the commercial type results which nearly approached these in excellence." He further adds: "In less than an hour after leaving the pasteurizer, the milk in all of the bottles had developed a distinct cream line, and the amount of cream appearing at the top of each bottle was sufficient to indicate that the rising of the cream had not been in any way impaired. The milk was pleasant to the taste and possessed no odor or taste which would suggest that it had been heated." U 6 MARKET DAIRYING The beer pasteurizing apparatus works automatically, the bottles passing successively from one compartment to another until the pasteurizing is completed. The water in the first compartment registers about no° F. From this point on, the water grows gradually hotter until the proper pasteurizing temperature has been reached, and then gradually drops to 6o° F. These machines have been adapted for milk by adding another compartment in which the milk can be cooled below 50 F. During the pasteurizing the bottles are completely im- mersed, and the results with beer as well as with milk- have been found more satisfactory when the pasteurizing is done with water than when steam is used. Undoubtedly apparatus will soon be found upon the market which will answer the purpose of small milk dealers. Many of the smaller milk dealers are now pas- teurizing bottled milk in a simple water tank. CHAPTER XIII. HOW TO SECURE A GOOD MARKET. Quality. As a rule it is easy enough to secure some kind of a market, but to secure the best frequently re- quires considerable effort. To get fancy prices requires first of all that the product be of superior quality. This is particularly true of milk. The extensive agitation in recent years for clean, pure milk has had the effect of putting a high premium upon such milk. The public is becoming aware of the dangers which lurk in dirty, un- sanitary milk and is willing to pay a good price for milk whose wholesomeness is unquestioned. Value of Advertising. To obtain big prices it is not enough to have products of superior quality, but what- ever particular merits they have must be forcibly brought to the attention of consumers. In other words, a certain amount of advertising is necessary. It is good policy to furnish prospective customers a few free samples and to distribute leaflets describing the conditions under which the products are produced and handled. If the milk is produced in clean, ventilated, whitewashed stables, and from cows which are regularly tested for tuberculosis; if the milk is handled by clean, healthy attendants and is thoroughly cooled and aerated immediately after milking; and if, in addition, all this is certified to by a competent inspector, an increase in prices and patronage is certain to follow when such facts are placed before the public. 117 118 MARKET DAIRYING The majority of city consumers have little conception of the conditions under which average milk is produced. For this reason the man who is producing clean milk will find it highly profitable to place in contrast vivid pictures of the conditions that yield average milk and those that yield sanitary milk. Investigate Outside Markets. Often outside mark- ets offer better prices for milk and cream than does the home market. This is especially true of cream. This product permits of long distance shipping and many out- side markets may be glad to get it at fancy prices when the home market may be entirely overstocked. Dairymen must not expect the market to come to them, however ; they must seek the market. A visit or corre- spondence with managers of cafes, hotels, restaurants, drug stores and ice cream manufactories in different cities, is frequently the means of securing more business and better prices. Where one is just starting in the dairy business or trying new markets, it is good policy, as a rule, not to ask very high prices at the start. First demonstrate the merits of your products. If these are of a high order consumers will gradually respond to demands for in- creased prices rather than lose the products. Too high prices at the start are likely to discourage prospective buyers, and thus deprive you of an opportunity to prove the value of your goods. Uniformity. One of the essentials in building up a good market is uniformity of product. Where this is lacking, improvements in other directions will be of little avail. On the other hand, products which are uniformly the same, week after week, and month after month, are TO SECURE A GOOD MARKET 119 likely to command good prices even when of only medium quality. Punctuality. Another essential in building up a good market is punctuality. If your customer expects his milk at 7:30, do not deliver it at 7:40; deliver early rather than late. If you are shipping cream or milk you cannot afford to miss your train — even a single time. It gen- erally means greater disappointment at the other end of the line than one would anticipate. Try to Please. Always put yourself in an attitude to please. If criticisms come concerning your products, you cannot afford to resent them. Usually there is reason for the criticism. Try to discover the trouble and remedy it. Delivery Outfit. Cleanliness and neatness must char- acterize the dairy business throughout. Milk wagons, cans, bottles, drivers, etc., must present a clean appear- ance. Where they do not, it is usually an easy matter to surmise the condition of milk. Use a Trade Mark.- The name or monogram of the dairy, placed upon the products and delivery wagons, guarantees genuineness and will materially assist in se- curing a better and more extended market. It is one of the best ways of advertising a superior product. Secure Your Market Early. If it is intended to sell cream for manufacture into ice cream, it is important to get a market early in the spring. It is difficult to find one in the flush of the ice cream season, because ice cream dealers, as a rule, contract considerably in advance of the time they need the cream. If it is intended to supply winter resorts, apply for the market early in the fall. What has been said here with reference to cream applies also to milk. 120 MARKET DAIRYING Secure Reliable Customers ; Where milk and cream are shipped some distance, it is important to determine beforehand the reliability of the buyer. As a rule it is good policy not to make more than three shipments before the first has been paid for. It is well, even where milk and cream are sold locally, to investigate the stand- ings of customers before their accounts have run up very high. Selling Direct to Consumers. No argument is need- ed to show the advantage of selling dairy products direct to consumers wherever this is possible. It means the elimination of the middleman whose profits are saved to the dairyman. Letterhead Stationery. It is not only businesslike to use stationery with a suitable letterhead, but it also serves to advertise the business. The following is sub- mitted as a suitable form of letterhead : Springdale Sanitary Dairy. J. C. Boone, Prop. Dealer in Pure, Bottled, Jersey Milk and Cream from Tuberculin Tested Cows. Reidsville, N. H 190. . CHAPTER XIV. MARKETING MILK AND CREAM RETAILING. Dip Method. The old method of hauling milk to the city in five, eight or ten gallon cans and removing each patron's allowance by means of a dipper or faucet, has been found so objectionable that the practice has been largely abandoned. The principal objections to this method are: (i) The admission of dust and bacteria to the milk while measuring it; (2) the use of unsteri- lized milk vessels by consumers; (3) exposure of the vessels to dust while on the steps of the consumer; (4) the use of unclean vessels by milkmen in measuring each customer's share; (5) lack of uniformity in the milk, espe- cially if removed from the cans by means of a faucet, in which case the first drawn milk is likely to be lowest in fat content; and (6) the possi- bility of drivers tampering with the milk. The Use of Bottles. Milk and cream intended for re- tail trade should be put into pint or quart bottles, for reasons cited above. The advantages of this method are apparent from the fact that the milk is bot- tled immediately after cooling and that it may be Milk Bottle. 121 122 MARKET DAIRYING kept in the same bottle until it is to be consumed. Whenever milk is changed from one vessel to another there is always more or less contamination from dust and bacteria. Bottling. For dairies having from ten to twenty cows, a can or vat provided with a sanitary faucet will do satisfactory work in filling bottles. A pouring can with a slightly curved spout may also be used for this purpose. For large dairies special bottle fillers will be found advantageous. These machines fill from two to twelve bottles at a time. In selecting a bottle filler secure one of simplest construction. This is important for sanitary reasons. Whatever method of filling is used, it is important to keep the milk well stirred while filling, so as to insure uniform quality in all the bottles. Special machines are now on the market for capping bottles. With the larger machines it is possible to cap many thousands of bottles in a day. The machines not only have the advantage of rapid capping, but eliminate possible infection from the hands where the capping is done by hand. The tendency at present is to seal the bottles with hermetic seals similar to those used on beer bottles. This insures against tampering, protects the lips of the bottles and makes possible pasteurization of the milk in bottles. A bottle ^o capped is shown in Fig. 40. RETAILING MILK AND CREAM 123 The bottles should be capped immediately after filling and only the best quality of caps should be used. Caps which lack stiffness or which have been poorly paraffined usually can be bought cheaply but they will prove expensive at any cost. During bottling the room should be kept damp to keep the air free from dust and bacteria. No air currents should be allowed to sweep in from the outside. Only clean laundered white suits should be worn by those in charge of the cooling and bottling. Milk Bottle Delivery Cases. On de- livery wagons the bottles are carried in cases holding twelve or more bottles each. These cases are made of galvan- ized iron or wood, or of both, and have light removable partitions inside, separ- ating the bottles to keep them from breaking. Galvanized iron cases, like that shown in Fig. 40.— Bottle Capped with Her- metic Seal. Fig. 41.— Galvanized Iron Milk Bottle Case. Fig. 41, are the most sanitary and also permit putting crushed ice around the bottles. 124 MARKET DAIRYING Fig. 42 shows a galvanized iron milk bottle case, enclosed by a box made of one-inch boards and pro- vided with a tight fitting cover. Cases of this kind should be used in warm weather to keep the milk cool during Fig. 42 —Insulated Galvanized Iron Milk Bottle delivery. On especially warm days, crushed ice should be used around the bottles. This style of case is also recommended where bottles are shipped. A great deal of milk is spoiled while in transit to the consumer. The last milk delivered on the route may be on the road five or six hours before it finally reaches its destination. If carried in open, uniced cases, on warm days, an exposure of such duration may easily shorten the keeping quality of the milk by eight or more hours. A matter of prime importance in delivering milk in bottles is to have them thoroughly sterilized before using. Unless this is done milk will not keep long and, what is worse, is likely to disseminate disease along the route. STANDARDIZING MILK AND CREAM 125 This danger is due to the bottles' passing from one home to another and eventually reaching a home in which there is some cantagious disease. Ir. such cases there is always a probability that the bottles may become infected with the disease germs. Frequency of Delivering Milk. When milk is cooled to 45 F. or below immediately after milking and is held at this temperature until it reaches the consumer, one delivery a day is sufficient. If it is desirable, however, to make two deliveries a day, these should be made inde- pendent of the milking; that is, the night's milk should be delivered in the morning and the morning's milk in the afternoon. In some sections, especially in the south, milk is sold with little or no cooling whatever. Hence, the practice of delivering the morning's milk before breakfast, and the night's milk before supper. This practice requires the first milking to be done shortly after midnight and the second milking shortly after midday, a drudgery wholly unnecessary and easily obviated by thoroughly cooling the milk. Delivery Wagons. These should be clean, covered, well painted, and provided with good springs. The name of the dairy should be printed on each side. A neat and at- tractive delivery wagon is essential in building up a good trade. STANDARDIZING MILK AND CREAM. This is a process by which milk and cream are brought to a definite percentage of fat. Cream producers are called upon to furnish cream of a definite richness, and different grades may be demanded by different buyers. The simplest way to meet such demands is to have the separator deliver cream somewhat richer than the rich- est grade called for and to reduce this to the required richness by adding skim-milk. 126 MARKET DAIRYING Reducing Cream with Skim=milk. When a definite quantity of standardized cream is called for, determine first the amount of original cream (cream as it leaves the separator) required according to the following rule: '* Rule : Multiply the number of pounds of standardized cream called for by its test and divide the product by the test of the original cream. The difference between the amounts of original and standardized cream represents the amount of skim-milk required. Problem: How many pounds each of 45% cream and skim-milk (zero test) are required to make 60 pounds of 18% cream? Applying the above rule we get, (60 X 18) -^45 = 24 — No. lbs. of original cream. 60 — 24 = 36 = No. lbs. of skim-milk. Milk may be standardized in the same way. Mixing Two Milks or Two Creams, or Milk and Cream, of Different Richness. In the preceding two formulas the test of the skim-milk was considered zero. When milks or creams of different tests are mixed the calculation becomes more difficult. Pearson, however, has devised a method by which calculations of this kind are very much simplified. This method is as follows: Draw a rectangle with two diagonals, as shown below. At the left hand corners place the tests of the milks or creams to be mixed. In the center place the richness STANDARDIZING MILK 'AND CREAM 127 desired. At the right hand corners place the differences between the two numbers in line with these corners. The number at the upper right hand corner represents the number of pounds of milk or cream to use with the richness indicated in the upper left hand corner. Like- wise the number at the lower right hand corner repre- sents the number of pounds of milk or cream to use, with the richness indicated in the lower left hand corner. Example: How many pounds each of 30% cream and 3.5% milk required to make 25% cream? 30% r==Zr ~^I 21.5 Lbs. 3.5 %\^— — ^J ^ LBS. 21.5, the difference between 3.5 and 25, is the number of pounds of 30% cream needed; and 5, the difference between 25 and 30, is the number of pounds of 3.5% milk needed. From the. ratio of milk and cream thus found, any definite quantity is easily made up. If, for example, 300 pounds of 25% cream is desired, the number of pounds each of 30% cream and 3.5% milk is determined as fol- lows: 21.5 + 5 = 26.5 21.5 X 300 = 243.4, the number of pounds of 30% cream. 26.5 5 26.5 X 300 == 56.6, the number of pounds of 3.5% milk. 128 MARKET DAIRYING SHIPPING MIIvK AND CREAM. The essential things in shipping milk and cream are cleanliness and low temperature. It is possible to keep milk and cream in good condition for two or three days, if produced and handled under cleanly conditions and Fig. 44. -Milk Can. Fig. 45.— Felt Jacket on Can. cooled directly after milking to 40 F. or below. This low temperature must be maintained when long keeping quality is desired. Every dairy should be provided with a good ice box or refrigerator, into which milk and cream SHIPPING MILK AXD CREAM 129 may be placed immediately after cooling and in which they may be kept until ready for shipment. Shipping in Cans. Various insulated cans are now upon the market and a number of these have been tested by the author. The tests showed that these cans possess about the same insulating effect as the felt jackets that are commonly wrapped around ordi- nary milk cans. Since the latter, as a rule, are more durable and more easily handled, they will be found more satisfactory when wrapped with a felt jacket than the so- called insulated ship- ping cans. When milk and cream are cooled close to freezing and placed in ordinary milk cans wrapped in felt jack- ets, they may be safe- ly shipped to any point that may be reached within 24 hours even i n warm weather. If the temperature of the milk and cream at the time of shipment is 50 F. or higher, then long distance ship- ment is best accomplished by the use of an ordinary can placed inside of a covered ice cream shipping tub con- taining ice. Such a tub has practically the same in- Fig. 46.— Screw Top Can. 130 MARKET DAIRYING sulating effect as a felt jacket, but is rather heavy and cumbersome and should not be used except in cases where it is necessary to pack ice around the cream or milk. The best results from the ice are secured by packing it in large lumps around the neck of the can. Shipping in Bottles. Where milk and cream are shipped in bottles, the latter should be placed in insulated delivery cases (Fig. 43) and surrounded with crushed ice. The cases should have the owner's address on them and must be kept locked while in transit. Mode of Shipping. The usual way of shipping milk and cream is by express. In the main dairy sections bag- gage rates are available. These rates are lower than ex- press rates and can be obtained nearly everywhere by special arrangement with the railroad companies. Shipping rates should always be obtained in advance of shipment and the charges should be prepaid. A con- siderable saving is certain to be effected by rigidly ad- hering to this practice. Insist upon getting the lowest rates possible. Pointers on Shipping. Have the name and address of your dairy permanently marked in brass upon every can and cover ; also have it sewed or stitched on the felt jackets. This is necessary to insure the return of your own goods. The name and address will be put upon the cans and covers by the dealer from whom they are pur- chased, if so requested; or, in case unmarked cans are already on the premises, the brass plates with the name and address may be purchased from dairy supply firms and placed upon the cans and covers by a local tinner. Even when labeled as indicated above, cans will oc- casionally get lost. Empty cans are usually returned free of charge and, for this reason, express receipts are com- SHIPPING MILK AND CREAM 131 monly not taken for them. This is a mistake. If the purchaser of your products will take a receipt for the empty cans, the express company becomes responsible for them in the event they are lost. Without the receipt it is next to impossible to claim damages for lost goods. The empty cans should be washed before they are re- turned. This should be done for sanitary reasons as well as for the protection of the cans, which are short-lived unless washed and dried immediately after use. Another matter of importance in shipping is to have the cans full to prevent churning. Fig. 47.— Lead Seal and Seal Press. It is necessary also to have the cans sealed to prevent tampering with the contents. The sealing is easily accom- plished by means of lead seals and a seal press (Fig. 47). In delivering the cream or milk at the station the de- livery man should see to it that the cans are put in as cool a place as possible. CHAPTER XV. profitable; side lines. Only a comparatively few of the thousands of milk dealers are as yet making use of the full possibilities of their business. It has always been taken for granted that milk and cream must be delivered daily to have them reach the consumer in a wholesome and palatable condition. Yet the same may be said about cottage cheese, buttermilk, cultured milk, club cheese, butter, eggs, ice cream, cream cheese and Neufchatel cheese, Pimento and other fancy cheeses. The sale of some of these products could be infinitely increased by supplying them in as good a condition as milk and cream, but to do this requires that they be delivered in just as fresh and palatable a condition. Fancy Cheese; The soft and fancy varieties of cheese are appreciated by all classes of people; their wholesomeness when fresh is superior to meat and their cost as a rule is considerably less. But what an insig- nificant amount of this class of cheese is consumed at the present time! If these perishable products would be manufactured by the milk dealers and delivered by them in a fresh condition, the consumption of soft and fancy cheese could undoubtedly be increased a hundredfold. At present these cheeses are shipped at heavy cost from manufacturer to city wholesaler who, in turn, de- livers them to the grocery stores — a roundabout way of handling that is both costly and unsatisfactory because 132 PROFITABLE SIDE LINES 133 the cheese is too old when it reaches the consumer. Of course the average milk dealer may know nothing about fancy cheese making, but he can learn as easily as any- one. The man whose business is continually expand- ing is the one who is continually expanding in knowl- edge. Eggs and Butter. Eggs and butter must be sold more direct in the future than they have been in the past, because their perishable nature does not permit of the roundabout method of marketing practiced at the present time. What an enormous saving there would be in middlemen charges and in reduced cost of de- livering by having one wagon, the milkman's wagon, carry the various perishable dairy products on a single trip which now require half a dozen or more trips! Ice Cream. Think of how much cheaper the milk dealer could furnish ice cream to his customers than the exclusive ice cream manufacturer who frequently must drive an extra two miles to make a single delivery. Of course, those city consumers who have no ice may not be in a position to handle the milk dealer's ice cream to best advantage, but most of the consumers of ice cream do have ice during the summer. Those cus- tomers who insist upon having their ice cream delivered, say, an hour before they expect to use it, let them patronize the city ice cream plant. It is quite certain, however, that the reduced cost at which milk dealers can deliver ice cream will secure for them the bulk of ice cream trade among those whom they are supplying with milk. Cultured Milk. The possibilities for well made cul- tured milk are practically unlimited. Already many large milk dealers are catering to the demand for this 134 MARKET DAIRYING product and the sale has increased enormously during the past few years. It is a product that should be supplied by all milk dealers, large and small. There is no drink which, by reason of its food and tonic value, relative cheapness and general wholesomeness, is so much entitled to become the leading of all beverages. It is up to the milk dealers to make this the national drink for all classes, rich and poor. Skimmilk=Buttertni1k. Well made skimmilk-but- termilk is very palatable and quite as wholesome as cultured milk ; indeed in a sense it is cultured milk, but this term should not be applied to fat-free milk. This product is especially commendable because of its cheap- ness. It answers all purposes of buttermilk and, when made right, is superior in quality. Reduced Delivery Expenses. Most of the milk dealers are running one-horse delivery wagons, and the sooner the milk dealer can add enough to his wares to run a two-horse delivery, just so soon will he be able to reduce the cost of delivery. Labor is expensive these days, and the labor with a two-horse wagon is no greater than that with the one-horse wagon. The milk dealer ought to be able to carry enough load on his route to justify the use of two horses to each wagon. The additional side lines suggested would soon double the milk dealer's load and would enable him to use two horses instead of one. If these additional lines would do nothing more than enable every driver to drive two horses and a whole load instead of one horse and half a load, the undertaking would be justified. CHAPTER XVI. STARTERS, OR LACTIC ACID CULTURES. The value of carefully selected cultures of lactic acid producing bacteria in cream ripening was first demon- strated by Dr. Storch, of Copenhagen, about twenty- five years ago. Since then the use of these cultures has spread so rapidly that few successful creameries can be found at the present time in which they are not used. Definition. Starter is the general term applied to cultures of lactic acid organisms, whether they have been selected artificially in a laboratory, or at creameries by picking out lots of milk that seem to contain these organ- isms to the exclusion of others. A good starter may be defined as a clean flavored batch of sour milk or sour skim-milk. The word starter derives its name from the fact that a starter is used to ''start" or assist the development of the lactic fermentation in cream ripening. Object of Starters. Cream ordinarily contains many kinds of bacteria — good, bad, and indifferent — and to insure the predominance of the lactic acid type in the ripening process it is necessary to reinforce the bacteria of this type already existing in the cream by adding large quantities of them in a pure form, that is, unmixed with undesirable species. The bacterial or plant life of cream may be aptly com- pared with the plant life of a garden. In both we find plants of a desirable and undesirable character. The 135 |36 MARKET DAIRYING weeds of the garden correspond to the bad fermentations of cream. If the weeds get the start of the cultivated vegetables, the growth of the latter will be checked or suppressed. So with the bacterial fermentations of cream. When the lactic acid bacteria predominate, other fermentations will be checked or crowded out. The use of a liberal amount of starter nearly always insures a majority of good bacteria and the larger this majority the better the product. Classification of Starters. Starters are divided into two general classes, namely, natural starters and com- mercial starters. The former consist of naturally soured milk or skim-milk and are generally less satisfactory than starters prepared from commercial cultures. There are comparatively few natural starters used at the pres- ent time. Commercial starters are sent out in hermetic- ally sealed bottles and, in the majority of cases, may be obtained in either liquid or powder form. The bacteria will keep longest in the powder preparation, but will be found most active in the liquid provided the same is used immediately. NATURAL STARTERS. Sour Milk and Skim=milk. Natural starters are those obtained by allowing milk, skim-milk, or possibly cream, to sour in the ordinary way. The earlier methods of using natural starters consisted in selecting milk or skim-milk from the patrons who furnished the best milk at the creamery, and allowing this to sour by holding it over till the following day. While good milk could be selected in this way, the method of souring it was very unsatisfactory. On warm days the milk might oversour, while on cooler days it would be STARTERS 137 found comparatively sweet unless a good deal of atten- tion was given to keeping the temperature where it would sour in the proper length of time. This method of starter making is rapidly falling into disuse. The most satisfactory natural starters are selected and prepared in the following manner : Secure, say, one quart of milk from each of half a dozen healthy cows not far advanced in lactation, and fed on good feed. Before drawing the milk, brush the flanks and udders of the cows and then moisten them with water or, preferably, coat thinly with vasaline to prevent dislodgement of dust. Then, after rejecting the first few streams, draw the milk into sterilized quart jars provided with narrow necks. Now allow the milk to sour, uncovered, in a clean, pure atmosphere at a temperature between 65 ° and 90 F. When loppered pour off the top and introduce the sample with the best flavor into fifty pounds of sterilized skim- milk and ripen at a temperature at which it will sour in twenty-four hours (about 65 ° F.). A starter thus selected can be propagated for a month or more by daily inoculating newly sterilized or pasteur- ized milk with a small amount of the old or mother starter. Usually three or four pounds of the mother starter added to one hundred pounds of pasteurized skim-milk will sour it in twenty-four hours at a temperature of 65 ° F. Under certain conditions of weather this amount may possibly have to be modified a little, for it is well known that on hot sultry days milk will sour more quickly at a given temperature than on cooler days. The* best rule to follow is to use enough of the mother starter to sour the milk in twenty-four hours at a temperature of 65 ° F. Buttermilk and Sour Cream. If the cream has a good flavor, a portion of this, or the buttermilk from it, 138 MARKET DAIRYING may be used as a starter. But in the case of unpasteurized cream, even though the flavor is good, there are always present some undesirable germs which will multiply in each successive batch of cream or buttermilk used as a starter, so that after a week's use the flavor may actually be bad. Where cream is slightly off flavored and a por- tion of this, or the buttermilk from it, is used as a starter, it will readily be seen that the taint will not only be transmitted but will multiply in the cream from day to day. The use of either cream or buttermilk as a starter is therefore not to be recommended. COMMERCIAL STARTERS. Commercial starters may consist of a single species of lactic acid organisms, but usually they are made up of a mixture of several species. These starters are pre- pared in laboratories where the utmost precautions are taken to keep them free from undesirable germs. Preparation. Most of the commercial cultures are sent out in one ounce bottles which are hermetically sealed. The method of making starters from them is the same for all whether they are obtained in the liquid or in the dry form. In making the first batch of commercial starter, the entire contents of the bottle is put into a quart of skim- milk, sterilized by keeping it at a temperature of 200 F. for two hours, and then cooling to 8o° which temperature should be maintained until the starter has thickened. A new starter is now prepared by introducing the quart of starter into fifty pounds of skim-milk, pasteurized by keeping it at a temperature of 170 to 185 ° for thirty minutes and then cooling to 65 ° F. All subsequent starters are prepared in the same way except that the amount of STARTERS 139 mother starter for inoculation must be reduced a little for a few days because the germs become more vigorous after they have propagated several days. In preparing the first starter from a bottle of culture it is necessary to have the skim-milk sterile. For if any spores should remain, the slow souring would give them a chance to develop which might spoil the starter. More- over, the cooked flavor imparted by the prolonged heating at high temperatures does not matter in the first starter as this should never be used to ripen cream. The first and second starters prepared from a new culture seldom have the good flavor produced in subsequent starters. The cause of this in all probability is the inactive condi- tion of the germs and the peculiar flavor of the medium in which they are sent out. In the starters prepared later the destruction of the spores is not so essential as the lactic acid germs are then in a vigorously growing condition which renders the spores practically harmless. At any rate the harm done by them would be less than that caused by the sterilizing process. When milk is pasteurized at 170 to 185 F. for thirty minutes the vegetative germs are destroyed and but little cooked flavor is noticeable. NATURAL VERSUS COMMERCIAL STARTERS. Experimental tests have shown that equally good results can be secured with commerical and natural starters. It is believed, however, that the average butter maker can get the best results with commercial starters. Too few are good judges of milk and for this reason are not always capable of selecting the best for natural starters. Standard commercial cultures can be relied upon as giv- ing uniformly good results. 140 MARKET DAIRYING From what has been said of the methods of preparing starters it must have been noticed that they are essentially the same for both the natural and the commercial, "the chief difference being in the original ferment, which in the case of the natural starter consists of a quart of selected milk allowed to sour naturally, while in the com- mercial it consists of a bottle of culture prepared in a laboratory. USING A STARTER EVERY OTHER DAY. During the winter when milk is received every other yyVi*y<—, &■• % £lsyL<4^™-~,&' ft % a 1 9 4 D 3 o MILK CREAM B M BOTTLES. Q 2 B < o MILK. CREAM. B. M BOTTLES. | \ i s I o 2 I m 1 s or i g 1 s \ 1 B I 1 a a z i t • Form of Route Book. The route book consists of loose leaves, upon which the names of customers are arranged alphabetically. The leaves are renewed each month, the old one being placed on file for future reference. The letters b. m. stand for buttermilk. Ledger. As a rule all accounts are settled monthly. The ledger form shown below serves satisfactorily as a permanent monthly record. On the debit side are recorded the sales and the total value of the tickets purchased. On the credit side are KEEPING ACCOUNTS 223 recorded all the receipts for the same period. The balance represents the difference between the debits and credits. Dr. ( )f6*^ $yyic£i Cr. DATE IMS. a 1 a TICKETS. i a DATE 1908 X TICKBTB. i i i i is ■ 1 ■ g fa , Jan 1-31 too % 10 /(? ST> Jan 1-3) 6.00 »/0 i 44 1 Bal. Jan Si 3 4- * V , Bal Fib 1 1 2. 00 * ,2 ¥ 1 r-^ =H . Fwm 1-29 -t Form of Ledger. Monthly Statement. At the end of each month a statement should be rendered to customers showing their indebtedness. A form like that herewith shown answers the purpose satisfactorily. SPRINUDALE SANITARY DAIBY, 4,C. BOONS. rroprt..v>r Ma. J&L jzfyi+ie/ REIDNVILJLE. N. H. toSPRINGDALE SANITARY DAIRY, J C. BOONE. Proprietor Htf-J-2* <&a^*^<&* 3 ZJ. / t+o yi***/^ Y*v>H^- e £- &JUL4L ho> «fi -sts^sAlZZcSi^ULd) htt&LL, f JV Xo UT g W 00 ZiT Monthly Statement. 224 MARKET DAIRYING Order Book for Supplies. For convenience as well as for permanent record, all orders should be made in duplicate in a book specially made for the purpose. The leaves in the order book are alternately marked "original" and "duplicate," the duplicate being made at the same time as the original by using carbon paper between the two. A suitable form of order blank is shown below. Original Springdale Sanitary Dairy. J. C. Boone, Prop. Order No Reidville, N. H 190. . To Dear Sir: Please deliver by the following: Invoice and ship to Springdale Sanitary Dairy, J. C. Boone, Prop., Reidville, N. H. Customer's Record Sheet. In place of tickets, milk dealers now usually leave cards with each customer. Each of these cards covers a period of one month and is provided with blank spaces in which the consumer indi- cates his daily wants in the line of milk, cream, etc. The milk dealer transcribes these wants into his route book, leaving the cards entirely in the possession of the cus- tomers. A sample of such cards is shown on the follow- ing page. KEEPING ACCOUNTS 225 THE WAUCOSTA DAIRY CO. 174 PINE STREET. Pasteurized milk and cream, buttermilk, cottage cheese, cultured milk and butter. Account for JUNE 191 2. Name . Address V Milk Cream B. M. Cheese C Milk Butter 43 Q Qts. | Pts. y 2 pt. 1 pt. Qts. Lbs. Qts. | Pts. Lbs. 0^ 1 2 3 4 fi 6 7 8 9 10 11 12 13 14 15 16 17 18 19 '?,() 21 22 23 24 25 2fi 27 28 29 30 31 Tt'l Note: This card is your property and all orders must be placed thereon and card put where driver can see it. Do not pay driver unless he signs this card. CHAPTER XXX. CONTROL OF CITY MILK SUPPLY. The need of safe-guarding the milk supply of towns and cities becomes evident when we consider the extent to which milk acts as a carrier of infectious diseases. During the past twenty years, more than one hundred and fifty epidemics of typhoid fever have been traced to milk infected with the typhoid bacillus. There are records of. twenty-eight epidemics of diphtheria and eighty or more of scarlet fever. Besides these epidemics, it is difficult to estimate how many thousands of isolated cases of these and various other diseases have been caused by infected market milk. The prevalence of tuberculosis among dairy cattle, alone, calls for a rigid control of city milk supplies. As stated elsewhere in this chapter, a large percentage of market milk contains the tubercule organism, and that the bovine tubercle bacillus can and does produce tuber- culosis in man has been established beyond a doubt by the Royal Commission on Human and Animal Tuber- culosis and by other notable scientific bodies and individ- uals. In addition to the danger of infection with strictly pathogenic bacteria, milk produced and handled under uncleanly conditions contains organisms which, while not classed with the pathogenic kinds, are nevertheless the cause of a high mortality among children under two years of age. These organisms come from manure 226 CONTROL OF CITY MILK SUPPLY ?27 and filth and are largely responsible for the diarrhea, summer complaint" or general gastro-intestinal diseases so common among infants and young children subsisting on cow's milk. Importance of Cleanliness. Milk furnishes an ideal medium for the development of a large variety of bac- teria and for this reason, when improperly handled, it is possible for many of the organisms which gain en- trance into it, to multiply thousands and even millions of times before the milk finally reaches the consumer's table. Another reason why extreme cleanliness should be practiced with milk is the fact that possibly no other food is naturally exposed to so many contaminating in- fluences as is milk in its production. If water should be squeezed by unclean hands from unclean cows confined in unclean stables, with particles of dirt and manure dropping into it in the process, it is certain that even the least fastidious persons would refuse to drink it. Yet thousands are daily consuming milk produced under such conditions,' apparently oblivious of the filth and bacteria contained in it. Two reasons may be given for this ap- parent indifference towards milk on the part of a large percentage of consumers : ( I ) the general ignorance re- garding bacteria and the part they play in milk; (2) the opaque color of milk which obscures the bulk of the dirt contained in it. To improve the quality of milk supplied to towns and cities, it is necessary to exercise a reasonable control over it, both at the farms as well as in the city where it is consumed. Most cities now have a well organized sys- tem of milk inspection and great improvement "in the composition and in the sanitary conditions surrounding 228 MARKET DAIRYING the production and handling of milk may be looked for in the near future. Inspection at the Farm. The past few years has witnessed a remarkable progress in general dairy inspec- tion which has largely come about through the employ- ment of better qualified inspectors and the realization by the inspectors that their work must be largely of an edu- cational character. Real effective milk inspection must begin at the farm. The cows must be examined to see that none are dis- eased ; attention must be given to the stables to see that they are kept clean and that they admit sufficient sunlight and air to make them sanitary; the purity of the well water must be ascertained ; outhouses must be of sanitary construction and removed a reasonable distance; suitable cleaning and sterilizing facilities should be available; the health of those entrusted with the milking and handling of the milk should be above suspicion; and in this way a hundred different matters need to be looked after. It is to be hoped, therefore, that cities will not only provide inspection within the city limits, but will have the great- est force of inspectors in the country where the milk is produced. In this connection it is suggested that an important qualification of the "country" inspector should be a good practical knowledge of herd management and barn con- struction. Expensive equipment is not necessary to pro- duce pure milk and inspectors that lack the practical knowledge to suggest changes within the limits of the farmer's pocketbook, are sure to fail in their mission of inspection. Stress is laid upon this point because there' are hosts of inspectors who have good chemical and bacteriological training along milk lines, but who lack CONTROL OF CITY MILK SUPPLY 229 a working knowledge along the lines suggested. Another matter for milk inspectors to remember is the fact that all unsanitary conditions are not necessarily the result of willful neglect or transgression. They may be the result of ignorance. In this connection it should be remembered that dairy inspection is a comparatively new matter and the ideals of many of the inspectors and fram- ers of health regulations can be attained only after months of patient education. Bacteriology itself is a compara- tively new science and it is, therefore, not so remark- able that there should be so much ignorance regarding bacteria and sanitation in general. A score card for judging dairy farms will be found in the appendix. Tuberculosis and Tuberculin Testing. Undoubtedly one of the most pressing problems confronting the city milk trade is the matter of obtaining milk from tuberculin tested cows. Numerous cities throughout the country have endeavored in the past, or are endeavoring at the present time, to pass and enforce ordinances requiring all milk to come from herds which the tuberculin test has shown to be free from tuberculosis. The opposition to such ordinances by milk producers is sometimes ex- tremely fierce, as recently experienced by the city of Mil- waukee. The producers objected to the ordinance re- quiring cows to be tested for tuberculosis, maintaining that the tuberculin test was not reliable. The matter was finally carried to the supreme court, but the courts affirm- ed the reliability of the tuberculin test in every case. The Tuberculin Test; The usefulness of this test as a diagnostic agent rests upon the fact that when a sub- stance called "tuberculin" is injected under the skin of an animal, the injection is followed by a rise of tempera- 230 MARKET DAIRYING ture in infected animals, while in those unaffected the temperature remains the same. It must be added, how- ever, that in the last stages of the disease, tuberculin fails as a diagnostic agent, but this is of little consequence since the disease is readily recognized in these stages by a physical examination. The tuberculin test should not be applied to cows in heat or shortly before and after calving; neither may reliable results be expected with cows suffering from garget or other diseases. A period of at least 60 clays should elapse before a retest is made for tuberculosis. In regard to the reliability of the test, there is plenty of evidence to show that when the testing is done by competent persons the test is almost infallible. In Cali- fornia, for instance, 817 out of 9,618 head tested reacted and 817 upon post-mortem examination showed tuber- culosis. The accuracy of the test in this case was 100%. In Massachusetts 86,223 were tested, and of the 10,760 that reacted, 99.34% showed tuberculosis. In Wiscon- sin, out of 408,000 tested, 24,784 were killed and 98.39% of these showed tuberculosis. We might go on this way indefinitely showing figures bearing upon the accuracy of the tuberculin test, and it is such figures that milk producers should be thoroughly acquainted with before being asked to submit their cows to the test. Regarding the efficiency with which the tuberculin testing is done, it cannot be denied that there is often occasion for criticism. The testing should be done by experienced men who have shown proficiency in this always prima facie evidence that the work is being con- line. The fact that the tester is a veterinarian is not ducted satisfactorily. We have many men that style themselves veterinarians who are nothing more nor less CONTROL OF CITY MILK SUPPLY 231 than "quacks," and when the testing is done by such men there is bound to be trouble. Efforts should be made to secure well-known, competent men to do the testing and to lay the qualifications of such men before the herd owners. Farmers Benefited by Tuberculin Test. There is one thing that should be strongly emphasized in the matter of getting milk producers to test their cows for tuberculosis, and that is the need of healthy cows in con- ducting a profitable dairy business. Entirely aside from the health consideration so far as they affect consumers .of milk, it is an imperative matter for milk producers to eliminate tuberculosis from their herds to insure a profitable business. Tubercular cows are sick cows, and it is folly to expect the best results from sick cows. If milk producers would fully understand the detriment to their business from keeping tubercular cows, it would not be necessary for city ordinances to compel them to cull out their infected animals. There is not a first-class dairyman in the country today who is willing to con- duct a dairy business without assuring himself that his herd is free from tuberculosis. This phase of tuberculin testing should be properly stressed when asking dairy- men to comply with city ordinances affecting the health of cows Greater co-operation in tuberculin testing can undoubt- edly be obtained by refraining from forcing this test upon the farmers until they have had a reasonable oppor- tunity to become acquainted with the efficiency and value of tuberculin testing. Education is needed here just as along general sanitary lines, and this should precede the enactment of stringent city ordinances. Presence of Tubercle Bacilli in Milk. That tuber- 232 MARKET DAIRYING cle bacilli are frequently found in milk is abundantly shown by actual statistics. Some years ago an investigation was made of the milk supply of the city of Washington by the Hygienic Laboratory, Public Health and Marine Hospital Service, Washington, D. C. This investigation disclosed the fact that approximately 11% of the milk of ioo or more dairies investigated contained tubercle bacilli. Out of 1287 samples of milk collected in fourteen European cities, including London, Liverpool, Paris, St. Peters- burg, Berlin and Copenhagen, 144, or 11.2%, contained tubercle bacilli. Bacterial Counts. One of the common aids em- ployed in determining the purity of milk is to count the number of bacteria contained in it. In general there is a fair relation between the number of bacteria and the purity of the milk, and when the bacteria count is sup- plemented with an inspection of the conditions under which the milk is produced and handled it has consider- able value. On the other hand, we should not forget that a bacterial count alone is likely to lead to very erroneous conclusions regarding the wholesomeness of milk. To illustrate, let us compare two milks produced under identical conditions as to cleanliness. If one of the milks has been promptly cooled to 45 ° F. and kept at this temperature it may contain only 5000 bacteria per c. c. while the other sample, if poorly cooled, may contain 1,000,000 per c. c. The higher temperature has given the bacteria in the latter sample an opportunity for rapid development while the temperature (45 ° F.) of the former sample has checked the growth of the bacteria contained in it. If the milks were produced under clean- ly conditions, the increase in the number of bacteria in CONTROL OF CITY MILK SUPPLY 233 the sample kept at the higher temperature will be largely of the lactic kind and may be practically as wholesome as the sample containing only 5,000 bacteria per c. c. From the standpoint of safety, it is of far greater consequence to know the kind of bacteria present in milk than to know the actual numbers. For example, a sam- ple of milk may be produced under the strictest hygienic conditions, but if not properly cooled may show ten mil- lion bacteria per c. c. On the other hand, another sample of milk may be produced from diseased cows under filthy condition, if thoroughly cooled immediately after milking may contain less than ten million bacteria per c. c. Where bacterial counts have their greatest value in determining the purity of the milk is when the number of bacteria does not exceed 20,000 per c. c. Only under cleanly conditions can milk be obtained containing less than 20,000 bacteria per c. c. when delivered to con- sumers. Composition of Milk and Cream. Standards for milk, cream and ice cream are now found in most states and in the larger cities of the country. These standards, in the case of milk, call for a minimum per cent of fat, solids not fat and total solids ; in cream and ice cream, as a rule, only a minimum per cent of fat is considered. The total solids are obtained by adding the fat and solids not fat, and where there are standards for the latter two, no standard for total solids is needed. The minimum per cent of fat in milk called for by the standards varies from 2.5 to 3.7; for solids not fat the minimum varies from 8 to 9.5 per cent, while the minimum for total solids varies from n to 13 per cent. The minimum limit for fat in cream ranges from 15 to 234 MARKET DAIRYING 20 per cent; for ice cream, from 8 to 16 per cent. Consumers have hitherto been too indifferent regard- ing the composition of the milk they buy; they have failed properly to consider milk from the standpoint of a food. In most cities there is a wide variation in the composition of milk sold by different dealers, and often the highest priced milk will be found the cheapest when considered from a food standpoint. A quart of milk con- taining 5.5 per cent fat is worth fully 50 per cent more than one containing only three per cent. When compared with other foods, such as meat and cheese, milk at prevailing prices is a cheap food. Milk dealers should impress this fact upon their patrons. Those who sell a good quality of milk will find it profit- able to stamp the per cent of fat on the bottle cap. City milk authorities should encourage the 5 quality basis of handling milk as much as possible, because it will promote justice and honesty. The subject ^of buy- ing and selling milk on the butter fat basis is discussed in chapter XXVII. Sterile Milk Vessels. Much disease is disseminated through unsterile milk bottles. Every milk dealer's bot- tles at one time or another reach homes where there are persons affected with some contagious disease, and bot- tles will in many cases become infected with the disease producing organisms. A number of epidemics have been directly traced to unsterile milk bottles. In too many instances milk bottles are not sufficiently sterilized, and some milk dealers make no attempt whatever to have the bottles sterile; the main consideration with them is to have the bottles clean. The realization of the importance of having milk bottles sterile has started a movement to pasteurizing the milk in the bottles. CONTROL OF CITY MILK SUPPLY 235 The matter of sterile milk bottles means a great deal to the health of milk consumers, and milk inspectors should see to it that this phase of inspection receives the necessary consideration. There is urgent need, too, of directing more attention to milk cans. A large per- centage of milk shipping cans is entirely unfit for han- dling milk. Rust\- and badly bruised cans should be con- demned. Another matter that should be insisted upon is to have the cans washed and sterilized before returning them to the milk producers. Pasteurization. A number of cities in the United States have deemed it wise to require the pasteurization of all milk coming from cows that are not known to be free from tuberculosis. If properly done, there is no question whatever that pasteurization of milk as it is now received in most cities, is a safe-guard to health. See chapter XII. Temperature and Age Regulations. To hold milk in good condition until it reaches the consumer requires that it be kept at a low temperature. Many cities have passed regulations fixing a minimum temperature at which milk shall be transported and handled, and good results have followed such regulations. Low temperatures, however, like many other good things, are often abused as in the case of ice cream manufacturers. Some hold ice cream weeks before it goes to the consumer, believing that no bacterial develop- ment takes place at storage temperatures. While cold materially retards the growth of all bacteria and com- pletely stops that of many, there is probably no minimum temperature at which all bacterial development stops. That there is abundant bacterial development in cream is conclusively shown in Bulletin 41, of the Hygienic 236 MARKET DAIRYING Laboratory, Public Health and Marine Hospital Service, Washington, D. C. In the investigations reported in this bulletin, samples of ice cream were purchased from ice cream dealers and stored at temperatures ranging form o° to io° above zero F. The initial bacterial count of the samples varied from 10,000,000 to 135,000,000 per c. c. As a rule, at the end of the third day of storage the bacteria had nearly doubled in number, but from that point on there was a gradual decrease so that on the 14th day the number was less than in the initial count. From the 14th day on the number increased again and so rapidly that on the 27th day of storage some of the sam- ples showed eighteen times as many bacteria as were found in the initial count. In other experiments it was found that some samples showed marked bacterial growth at 5.8 below zero (F.). It is usually the obnoxious kinds of bacteria that develop at low temperatures. The development of ptomaines is most frequently noticeable in milk or cream that have been kept at low temperatures a long time. The prolonged storage of milk, cream and ice cream at low temperatures should, therefore, be prohibited. MILK ADULTERATIONS. Watering and Skimming. Up to within recent years the chief duty of milk inspectors was to guard against watering and skimming of milk. Vigilance in this matter is still very necessary, though at present the efforts of inspectors is directed chiefly along sanitary lines. In connection with the subject of watering and skim- ming, it should be remembered that most states require CONTROL OF CITY MILK SUPPLY 237 that milk be sold as it comes from the cow; that is, it would be illegal to remove a part of the fat from milk, even if this would leave it above the minimum composi- tion fixed by law. The matter of detecting watering and skimming is discussed in chapter VIII. Preservatives and Dirt. Preservatives are often found in market milk. Those most commonly used are, boracic acid, formalin, salicylic acid and carbonate of soda. The use of these preservatives materially prolongs the keeping quality of the milk owing to their antiseptic properties. Every effort should be made, however, to inflict maximum punishment upon users of preservatives because their poisonous nature makes them very detri- mental to health. So far as dirt is concerned, it cannot technically be classed as a milk adulterant, though in its effects it may be fully as detrimental to health as preservatives. The presence of dirt in milk presupposes the presence of an undue number of dirt-loving bacteria which, at least so far as babies and young children are concerned, are perhaps just as detrimental to health as preservatives. Filthy milk has killed thousands of children under two years of age, and its use should be strictly prohibited. The methods of determining preservatives and dirt in milk are discussed in Chapter XXV. Bad Fermentations. It has already been stated that the number of bacteria in any given sample of milk is of less consequence than the class to which they belong. Filthy milk, if promptly and thoroughly cooled, may come within the numerical limit established for bacteria ,by any particular city, yet such milk may be extremely 238 MARKET DAIRYING unwholesome, because the preponderance of bacteria is of the undesirable kind. The character of such milk is easily detected by means of fermentation tests described in Chapter XXIV. CHAPTER XXXI. BUTTERMAKING. This chapter will be discussed under three heads : Part I. Theory and Methods of Cream Ripening. Part II. The Control of the Ripening Process. Part III. Cream Acid Tests. PART I. — THEORY AND METHODS OF CREAM RIPENING. Cream ripening is a process of fermentation in which the lactic acid organisms play the chief role. In every-day language, cream ripening means the souring of the cream. So important is this process that the success or failure of the butter maker is largely determined by his ability to exercise the proper control over it. In common creamery practice the time consumed in the ripening of cream varies from six to twenty- four hours and includes all the changes which the cream undergoes from the time it leaves the separator to the time it enters the churn. Object. The ripening of cream has for its prime object the development of flavor and aroma in butter, two qualities usually expressed by the word flavor. In addition to this, cream ripening has several minor pur- poses, namely : ( I ) renders cream more easily churnable ; (2) obviates difficulties from frothing or foaming in churning; (3) permits a higher churning temperature; (4) increases the keeping quality of butter. Flavor. This, so far as known at the present time, 239 240 MARKET DAIRYING is the result of the development of the lactic fermentation. If other fermentations aid in the production of this im- portant quality of butter, they must be looked upon as secondary. In practice the degree or intensity of flavor is easily controlled by governing the formation of lactic acid. That is, the flavor develops gradually with the increase in the acidity of the cream. Sweet cream butter for example is almost entirely devoid of flavor, while cream with an average richness possesses the maximum amount of good flavor possible when the acidity has reached .6%. Exhaustive experiments conducted by the author (See Rept. Wis. Exp. Sta., 1905) show that the desirable butter flavor develops in the milk serum (skimmilk) and is absorbed from this by the butterfat. Such absorption may take place either during the ordinary course of cream ripening, or during the process of churning as would be the case when well ripened skimmilk (starter) is added to sweet cream and the mixture churned immediately. This explains why in creamery practice such good results have been obtained by churning sweet cream immediately after the addition of a large amount of well ripened starter. Churnability. Practical experience shows that sour cream is more easily churnable than sweet cream. This is explained by the fact that the development of acid in cream tends to diminish its viscosity. The concussion pro- duced in churning causes the little microscopic fat glob- ules to flow together and coalesce, ultimately forming the small granules of butter visible in the churn. A high viscosity impedes the movement of these globules. It is BUTTBRMAKWG 241 evident, therefore, that anything that reduces the viscosity of cream, will facilitate the churning. As a rule, too, the greater the churnability of cream the smaller the loss of fat in the buttermilk. Frothing. Experience shows that ripened cream is less subject to frothing or foaming than unripened. This is probably due to the reduced viscosity of ripened cream and the consequent greater churnability of same. Temperature. Sour cream can be churned at higher temperatures than sweet cream with less loss of fat in the buttermilk. This is of great practical importance since it would be difficult, if not impossible, for most creameries to get low enough temperatures for the suc- cessful churning of sweet cream. Indeed, many cream- eries fail to get a low enough churning temperature for ripened cream. Keeping Quality. It has been found that butter with the best keeping quality is obtained from well ripened cream. It is true, however, that butter made from cream that has been ripened a little too far will posesss very poor keeping quality. An acidity of .5% should be placed as the limit when good keeping quality is desired. METHODS OF CREAM RIPENING. There are three ways in which cream is ripened at the present time : 1. By the unaided development of the lactic fermenta- tion called natural ripening. 2. By first destroying the bulk of the bacteria in cream by heat and then inoculating same with cultures of lactic acid bacteria. This method is known as pasteurized cream ripening. 242 MARKET DAIRYING 3. By the aided development of the lactic fermenta- tion called starter ripening. I. NATURAL RIPENING. By this is meant the natural souring of the cream. In this method no attempt is made to repress the abnormal fermentations or to assist in the development of the lactic. From the chapter on Milk Fermentations we have learned that milk normally contains a number of different kinds of germs, frequently as many as a dozen or more. Natur- ally, therefore, where this method of ripening is practiced, a number of fermentations must go on simultaneously and the flavor of the butter is impaired to the extent to which the abnormal fermentations have developed. If the cream is clean and uncontaminated the lactic fermentation greatly predominates and the resulting flavor is good. If, on the other hand, the cream happens to contain many bad germs the probability is that the abnormal ferments will predominate and the flavor of the butter will be badly "off." Where cream is therefore allowed to take its own course in ripening the quality of the butter is a great uncertainty. This method, though still practiced by many butter mak- ers, is to be condemned as obsolete and unsatisfactory. 2. PASTEURIZED CREAM RIPENING. Theoretically and practically the ideal way of making butter is to pasteurize the cream, a process which consists in heating cream momentarily to a temperature of 160 to 185 F. and then quickly cooling to 6o° F. In this manner most of the bacteria in the cream are destroyed. After this treatment the cream is heavily inoculated with the lactic acid bacteria, and the lactic fermentation is given BUTTERMAKIXG 243 a favorable temperature for development. When cream is treated in this way the lactic fermentation is practically the only one present and a butter with the desirable flavor and aroma is the result. It is the only way in which a uniform quality of butter can be secured from day to day. This system of cream ripening is almost universally fol- lowed in Denmark, whose butter is recognized in all the world's markets as possessing qualities of superior excel- lence. The method is also gradually gaining favor in America and its general adoption can only be a matter of time. In the chapter on Cream Pasteurization this method is discussed in detail. 3. STARTER RIPENING. This method of ripening consists in adding "starters," or carefully selected sour milk, to the cream after it leaves the separator. A full discussion of starters will be found in the following chapter. In America this is at present the most popular method of cream ripening. While it does not, and can not, give the uniformly good results obtained by pasteurizing the cream, it'is far superior to natural or unaided ripening. When we have a substance which contains many kinds of bacteria, there naturally follows a struggle for exist- ence and the fittest of the species will predominate. We always have a number of different types of bacteria in cream, both desirable and undesirable. The latter can be held in check by making the conditions as favorable as possible for the former. Fortunately, when milk is properly cared for the latic acid germs always pre- dominate. But where milk is received at the creamery from 30 to 200 patrons, undesirable germs are frequently present in such large numbers as to seriously endanger 244 MARKET DAIRYING the growth of the lactic acid bacteria. However, when a large amount of starter containing only lactic acid germs is added to the cream from such milk these organisms are certain to predominate. The best results with the starter method are secured when the milk is received at the creamery in a sweet condition and when a large amount of starter is used. Generally when milk is received in a sweet condition, especially during the summer months, it indicates that it has been thoroughly cooled and that the germs are present only in small numbers. When the cream from such milk is heavily inoculated with lactic acid germs by adding a starter, the development of the lactic fermenta- tion is so rapid as to either check or entirely suppress the action of undesirable bacteria that may be present in the cream. part ii. — the; control op the; ripening process. In Part I an attempt was made to convey some idea as to our present theory and methods of cream ripening. We learned that the highly desirable flavor and aroma of butter are produced by the development of the lactic fermentation. In the following discussion we shall take up the means of controlling this fermentation and treat of the more mechanical side of cream ripening. This will include: I. The time the starter should be added to the cream ; 2. The amount of starter to be added ; 3. The ripening temperature; 4. Time in ripening; 5. Agitation of cream during ripening; 6. Means of controlling tem- perature. 1. The value of a starter in cream ripening has already been made evident in the discussion of the theory of cream ripening. To secure the maximum effect of a starter it should be added to the cream vat soon after the separation BUTTERMAKIXG 245 of the milk has begun but not until the cream has reached a temperature of 70 ° F. The cream thus coming in con- tact with the starter as it leaves the separator insures a vigorous development of the starter germs, so that by the time the separation is completed, the starter fermentation is almost certain to predominate, especially when a large amount of starter is used. 2. The maximum amount of starter that may be con- sistently used is one pound to two pounds of cream. A larger amount than this would be liable to result in too thin a cream. Experience teaches us that the maxi- mum richness of cream permissible in clean skimming under average conditions is 50%. Adding one pound of starter to two pounds of such cream would give us ^33 1-3 % cream, the ideal richness for churning. But this amount of starter is rarely permissible on account of the poor facilities for controlling the temperature of the cream. 3. Since the lactic acid bacteria develop best at a temperature of 90 to 98 F. it would seem desirable to ripen cream at these temperatures. But this is not practicable because of the unfavorable effect of high tem- peratures on the body of the cream and the butter. Good butter can be produced, however, under a wide range of ripening temperatures. The limits may be placed at 60 ° and 8o°. Temperatures below 6o° are too unfavorable for the development of the lactic acid bacteria. Any check upon the growth of these germs increases the chances for the development of other kinds of bacteria. But it may be added that when cream has reached an acidity of .4% or more, the ripening may be finished at a temperature between 55 ° and 60 ° with good results. In general practice a temperature between 60 ° and 70 gives 246 MARKET DAIRYING the best results. This means that the main porti©n of the ripening is done at this temperature. The ripening is always finished at temperatures lower than this. 4. As a rule quick ripening gives better results than slow. The reason for this is evident. Quick ripening means a rapid development of the lactic fermentation and, therefore, a relatively slow development of other fer- mentations. Practical experience shows us that the growth of the undesirable germs is slow in proportion as that of the lactic is rapid. For instance, when we attempt to ripen cream at 55 ° F., a temperature unfavor- able for the growth of the lactic acid bacteria, a more or less bitter flavor is always the result. This is so because the bitter germs develop better at low tempera- tures than the lactic acid bacteria. The main portion of the ripening should be done in about six hours. After this the temperature should be gradually reduced to a point at which the cream will not overripen before churning. 5. It is very essential in cream ripening to agitate the cream frequently to insure uniform ripening. When cream remains undisturbed for some time the fat rises in the same way that it does in milk, though in a less marked degree. The result is that the upper layers are richer than the lower and will sour less rapidly, since the action of the lactic acid- germs is greater in thin than in rich cream. This uneven ripening leads to a poor bodied cream. Instead of being smooth and glossy, it will appear coarse and curdy when poured from a dipper. The im- portance of stirring frequently during ripening should therefore not be underestimated. 6. The subject of cream cooling is a very important BUTTBRMAKING '247 one and will be discussed under the head of cream ripeners. CREAM RIPENERS. During the summer months much butter of inferior quality is made by overripening the cream and churning at too high a temperature. This is due chiefly to a lack of proper cooling facilities. With the open cream vats the control of temperature is a difficult thing. For- tunately these vats have been largely replaced by the more modern cream ripeners. These ripeners possess two important advantages over the open vats, namely: first, they permit a more rapid cooling by agitating the cream while cooling ; second, they maintain a more uniform tem- perature because of tight fitting covers and better all round construction. There are a number of different makes of ripeners on the market that are giving good satisfaction. Since some of these ripeners are so constructed as to render the addition of ice to the water in them impossible, they can not therefore be considered complete without an ice water attachment. In Fig. 53 an ice water tank may be seen attached to the ripener. Tank A contains ice water which is kept circulating through the ripener by means of pump B. By using the water over and over again, only a very small quantity of ice is required in cooling cream to the desired tempera- ture. When the great cooling power of ice is once fully understood it is easy to see what a great amount of cooling a small quantity of ice will do. One pound of ice in melting will give out 142 times as much cold as one pound of water raised from 32 to 33 ° F. In other 248 MARKET DAIRYING words, the cooling power of ice is 142 times as great as that of water. With uniced water, a low temperature is not possible. On warm days the ripener may be run during the greater Fig. 53.— Showing method of circulating ice water through ripener. part of the day without reducing the temperature below 56 F., and this too when the water is pumped directly from the well into the ripener. It is rarely possible to obtain a lower temperature than this with water that has a temperature of 51 ° to 52 ° F. as it enters the ripener. When we compare the quick cooling with iced water and the slow and inadequate cooling with uniced water, it is easily seen that the saving in fuel and wear and tear of machinery will more than cover the cost of the ice. Moreover, quick cooling has a very important ad- vantage in cream ripening. It permits the use of a large amount of starter which is not possible where good cool- ing facilities are not at hand. Using iced water makes it possible to have cream with the same degree of acidity 365 days in the year, and it is believed that the general BUTTERMAKING 249 use of the improved cream ripeners and ice water attach- ments will result in a great improvement in both the quality and uniformity of butter and do away with the dangerous practice of adding ice directly to the cream. CHURNING. Under the physical properties of butter fat it was mentioned that this fat existed in milk in the form of extremely minute globules, numbering about 100,000,- 000 per drop of milk. In rich cream this number is in- creased at least a dozen times owing to the concentration of the fat globules during the separation of the milk. So long as milk and cream remain undisturbed, the fat remains in this finely divided state without any tendency whatever to flow together. This tendency of the globules to remain separate was formerly ascribed to the supposed presence of a membrane around each globule. Later re- searches, however, have proven the falsity of this theory and we know now that this condition of the fat is due to the surface tension of the globules and to the dense layer of casein that surrounds them. Any disturbance great enough to cause the globules to break through this caseous layer and overcome their sur- face tension will cause them to unite or coalesce, a process which we call- churning. In the churning of cream this process of coalescing continues until the fat globules have united into masses visible in the churn as butter granules. CONDITIONS THAT INFLUENCE CHURNING. There are a number of conditions that have an impor- tant bearing upon the process of churning. These may be enumerated as follows: 250 MARKET DAIRYING i. Temperature. 2. Character of butter fat. 3. Acidity -of cream. 4. Richness of cream. 5. Amount of cream in churn. 6. Speed of churn. 7. Abnormal fermentations. 1. Temperature. To have the microscopic globules unite in churning they must have a certain degree of soft- ness or fluidity which is greater the higher the tempera- ture. Hence the higher the temperature, within certain limits, the quicker the churning. To secure the best results the temperature must be such as to churn the cream iri from thirty to forty-five minutes. This is brought about in different creams at quite different temperatures. The temperature at which cream must be churned is determined primarily by the character of the butter fat and partly also by the acidity and richness of the cream. Rule for Churning Temperature. A good rule to fol- low with regard to temperature is this : When the cream enters the churn with a richness of 30 to 35 per cent and an acidity of .5 to .6 per cent, the temperature should be such that the cream will churn in from thirty to forty- five minutes. This will insure an exhaustive churning and leave the butter in a condition in which it can be handled without injuring its texture. Moreover, the but- termilk can then be easily removed so that when a plug is taken with a trier the day after it is churned the brine on it will be perfectly clear. 2. Character of Butter Fat. The fat globules in cream from different sources and at different times have the proper fluidity to unite at quite different temperatures. BUTTBRMAKIN.G 251 This is so because of the differences in the relative amount of "soft" and "hard" fats of which butter fat is composed. When the hard fats largely predominate the butter fat will of course have a high melting point. Such fat may be quite hard at a temperature of 6o° while a butter fat of a low melting point would be comparatively soft at this temperature. For a study of the conditions that influence the hardness of butter fat the reader is referred to the discussion of the "insoluble fats" treated in the chapter on milk. 3. Acidity of Cream. This has a marked influence on the churning process. Sour or ripened cream churns with much greater ease than sweet cream because the acid renders it less viscous. The ease with which the fat globules travel in cream becomes greater the less the viscosity. Ripe cream will therefore always churn more quickly than sweet cream. Ripe cream also permits of a higher churning temperature than sweet which is of great practical importance where it is difficult to secure low churning temperatures. 4. Richness of Cream. It may naturally be inferred that the closer the fat globules are together the more quickly they will unite with the same amount of concus- sion. In rich cream the globules are very close together which renders it more easily churnable than thin cream. The former can therefore be churned in the same length of time at a lower temperature than the latter. The ideal richness lies between 30% and 35%. A cream much richer than this will stick to the sides of the churn which reduces the amount of concussion. The addi- tion of water to the churn will overcome this stickiness and cause the butter to come in a reasonable length of 252 MARKET DAIRYING time. It is better, however, to avoid an excessive richness when an exhaustive churning is to be expected. 5. Amount of Cream in Churn. The best and quick- est churning is secured when the churn is one-third full. With more or less cream than this the amount of concus- sion is reduced and the length of time in churning cor- respondingly increased. 6. Speed of Churn. The speed of the churn should be such as to produce the greatest possible agitation or concussion of the cream. Too high or too low a speed reduces the amount of concussion. The proper speed for each particular churn must be determined by experiment. 7. Abnormal Fermentations. The slimy or ropy fer- mentation sometimes causes trouble in churning by ren- dering the cream excessively viscous. Cream from single herds may become so viscous as to render churning im- possible. At creameries where milk is received from many herds very little trouble is experienced from these fer- mentations. CHURNS. A churn is a machine in which the cream is made to slide or drop, or is in some way agitated to bring about the union of the fat globules, which changes the liquid fat into a solid. For many years the factory churns had assumed the form of a box or barrel free from any inside fixtures. Such churns were revolved by power and did very satisfactory work. But it was necessary to transfer the butter, after it was churned, to a worker upon which it was worked. This transfer from one piece of apparatus to another was obviated by the invention of "combined" churns and BUTTBRMAKING 253 workers placed upon the market about two decades ago. These are provided with rollers inside, which remain stationary during churning, but can be made to revolve when it is desired to work the butter. The combined churns have to a great extent replaced the old box and barrel styles because of the many advan- tages they possess over the latter. The principal advan- tages may be stated as follows : 1. They occupy less space. 2. Require less belting and fewer pulleys. 3. The churn can be kept closed while working which keeps the warm air and flies out during the summer. 4. The butter can be made with considerably less labor. A few disadvantages might be mentioned such as the greater original cost and the greater difficulty of cleaning and salting. But with proper care the butter may be evenly salted and the churns kept clean. For small dairymen there are no better churns than the barrel • churns. They are simple, cheap, and answer every requirement for a satisfactory churning of cream, but dairymen who have 50 or more cows will find the dairy size combined churn and worker an advantage. What dairymen should strictly avoid in the way of churns is the so-called one-minute churns and other rapid churn- ing devices. CHURNING OPERATIONS. Preparing the Churn. Before adding the cream, the churn should be scalded with hot water and then thoroughly rinsed with cold water. This will "freshen" 254 MARKET DAIRYING the churn and fill the pores of the wood with water so that the cream and butter will not stick. Straining Cream. All cream should be carefully strained into the churn. This removes the possibility of white specks in butter which usually consist of curd or dried particles of cream. Adding the Coflor. The amount of color to be added depends upon the kind of cream, the season of the year, and the market demands. Jersey or Guernsey cream requires much less color than Holstein because it contains more natural color. During the summer when the cows are feeding on pastures the amount of color needed may be less than half that required in the winter when the cows are feed- ing on dry feed. Different markets demand different shades of color. The butter must therefore be colored to suit the market to which it is shipped. In the winter time about one ounce of color is required per one hundred pounds of butter. During the summer less than one-half ounce is usually sufficient. In case the color is not added to the cream (through an oversight) it may be added to the butter at the time of working by thoroughly mixing it with the salt. When the colored salt has been evenly distributed through the butter the color will also be uniform throughout. Kinds of Color. There are two classes of butter color found upon the market. One is a vegetable color having its origin in the annatta and other plants, the other is a mineral color, a product of coal tar. Both are entirely satisfactory so far as they impart to butter a desirable color. But from a sanitary standpoint the vegetable color BUTTERMAKING 255 seems to be preferred and this is the color now used in creameries. Gas' in Churn. During the first five minutes of churn- ing the vent of the churn should be opened occasionally to relieve the pressure developed inside. This pressure according to Babcock "is chiefly due to the air within becoming saturated with moisture and not to gas set free from the cream. ,, Size of Granules. Butter should be churned until the granules are about half the size of a pea. When larger than this it is more difficult to remove the buttermilk and distribute the salt. When smaller, some of the fine grains are liable to pass out with the buttermilk, and the per- centage of water in the butter is reduced. When the granules have reached the right size, cold water should be added to the churn to cause the butter to float. Salt will answer the same purpose. The churn is now given two or three revolutions and the buttermilk drawn off. Washing Butter. One washing in which as much water is used as there was cream is usually sufficient. When butter churns very soft two washings may be advantageous. Too much washing is dangerous, how- ever, as it removes the delicate flavor of the butter. Too much emphasis cannot be laid upon the importance of using clean, pure water for washing. Experiments conducted at various experiment stations have shown that impure water seriously affects the flavor of butter. When the water is not perfectly pure it should be filtered or pasteurized. SALTING. It is needless to say that nothing but the best grades of salt should be used in butter. This means salt readily 256 MARKET DAIRYING soluble in water and free from impurities. If there is much foreign matter in salt, it will leave a turbid appear- ance and a slight sediment when dissolved in a tumbler of clear water. Rate of Salt. The rate at which butter should be salted, other conditions the same, is dependent upon market demands. Some markets like Boston require much salt in butter while some buyers in the New York market require scarcely any. The butter maker must cater to the markets with regard to the amount of salt to use as he does with regard to color. The rate of salt used does not necessarily determine the amount contained in butter. For instance it is per- fectly possible under certain conditions to get a higher percentage of salt in butter by salting at the rate of one ounce per pound than is possible under other conditions by salting at the rate of one and a half ounces. This means that under some conditions of salting more salt is lost than under others. The amount of salt retained in butter is dependent upon : 1. Amount of drainage before salting. 2. Fineness of butter granules. 3. Amount of butter in churn. 1. When the butter is salted before the wash water has had time to drain away, any extra amount of water remaining will wash out an extra amount of salt. It is good practice, however, to use a little extra salt and drain less before adding it as the salt will dissolve better under these conditions. 2. Small butter granules require more salt than large ones. The reason for this may be stated as follows : The surface of every butter granule is covered with a thin BUT TERM A KING 257 film of water, and since the total surface of a pound of small granules is greater than that of a pound of larger ones, the amount of water retained on them is greater. Small granules have therefore the same effect as insuffi- cient drainage, namely, washing out more salt. 3. Relatively less salt will stick to the churn in large churnings than in small, consequently less will be lost. Standard Rate. The average amount of salt used in butter made in the combined churns comes close to one and a half ounces per pound of butter. But the rate de- manded by different commission men may vary from no salt to two and a half ounces per pound of butter. With the combined churns great care must be exercised to get the salt evenly distributed from one end of the churn to the other as it can not redistribute itself in the working. Brine Salting. This consists in dissolving the salt in water and adding it to the butter in the form of a brine. This will usually insure an even distribution with less working since the salt is already dissolved. Where butter containing a high percentage of salt is demanded the method of brine salting is not practical, because it limits the amount that can be incorporated in butter. Where there is difficulty in securing an even distribu- tion of the salt without excessive working, an oversatu- rated brine may be used to advantage. Salt added to butter in this form very quickly dissolves and a butter with any degree of salt is possible. But it is believed that where butter is drained little and a somewhat higher rate of salt is used, dry salting will never require overworking and will insure greater uni- formity than is possible with brine salting. Object of Salting. Salt adds flavor to butter and 258 MARKET DAIRYING materially increases its keeping quality. Very high salt- ing, however, has a tendency to detract from the fine delicate aroma of butter while at the same time it tends to cover up slight defects in the flavor. As a rule a butter maker will find it to his advantage to be able to salt his butter rather high. Salt an Absorbent. Salt very readily absorbs odors and must therefore be kept in clean, dry places where the air is pure. Too frequently it is stored in musty, damp store rooms where it will not only lump, but become impregnated with bad odors which seriously impair the quality of the butter. WORKING BUTTER. The chief object in working butter is to evenly incor- porate the salt. Working also assists in expelling moisture. After the wash water has sufficiently drained away, the salt is carefully distributed over the butter and the churn revolved a few times with the rollers stationary. This will aid in mixing the salt and butter. The rollers are then set in gear and the butter worked until the salt has been evenly distributed. To work butter twice reduces the water content, but is a safeguard against mottles. How Much to Work. Butter is worked enough when the salt has been evenly distributed. Just when this point has been reached can not always be told from the appear- ance of the butter immediately after working. But after four or six hours standing the appearance of white Streaks or mottles indicates that the butter has not been sufficiently worked. The rule to follow is to work the butter just enough to prevent the appearance of mottles BUTTERMAKING 259 after standing about six hours. Just how much working this requires every butter maker must determine for him- self, by experiment, for the reason that there are a number of conditions that influence the length of time that butter needs to be worked in a combined churn. These condi- tions are : i. Amount of butter in the churn. 2. Temperature of the butter. 3. Time between workings. 4. Size of granules. 5. Solubility of salt. 1. When there is a moderately large amount of butter in the churn the working can be accomplished with fewer revolutions than with a small amount. Satisfactory work- ing can not be secured, however, when the capacity of the churn is overtaxed. 2. Hard, cold butter is difficult to work because the particles will not knead together properly. 3. A moderately long time between workings allows the salt to dissolve and diffuse through the butter and hence reduces the amount of working. 4. Coarse or overchurned butter needs a great deal of working because of the greater difficulty of distribu- ting the salt. 5. A salt that does not readily dissolve requires exces- sive working and is therefore productive of overworked butter. With such salt the brine method of salting is undoubtedly preferable. 260 MARKET DAIRYING DIFFICULT CHURNING. The causes of trouble in churning may be enumerated as follows: (i) thin cream, (2) low temperature, (3) sweet cream, (4) high viscosity of cream, (5) churn too full, (6) too high or too low speed of churn, (7) colos- trum milk, (8) advanced period of lactation, and (9) ab- normally rich cream. Foaming. This is usually due to churning a thin cream at too low a temperature, or to a high viscosity of the cream. When caused v by these conditions foaming can usually be overcome by adding warm water to the churn. Foaming may also be caused by having the churn too full, in which case the cream should be divided and two churnings made instead of one. CLEANING CHURNS. After the butter has been removed, the churn should be washed, first with moderately hot water, next with boiling hot water containing a little alkali, and finally with hot water. If the final rinsing is done with cold water the churn dries too slowly, which is apt to give it a musty smell. This daily washing should be supplemented once a week with a washing with lime water, which is prepared as follows : Gradually slake half a bushel of freshly burned lime by adding water to it at short intervals until about 150 pounds of water has been added. Stir the mixture once every half hour for several hours, after which allow it to remain undisturbed for about ten hours. This permits the undissolved material to settle. The clear liquid is now poured off and added to the churn, which is BUTTERMAKING 261 slowly revolved for at least half an hour so that the lime water may thoroughly penetrate the pores of the wood. Nothing is equal to the cleansing action of well pre- pared lime water and its frequent use will prevent the peculiar churn odor that is bound to develop in churns not so treated. The outside of the churn should be thoroughly cleaned with moderately hot water containing a small amount of alkali. Churning Cream Immediately After Adding the Starter. Where much hand separator cream is handled, it is usually received with varying amounts of acid, rang- ing in some cases from 0.15% to 0.8%. When the average acidity of the cream is such that when treated with a large amount of starter the mixture will show 0.5% acid or more, the cream should be churned as soon as the proper churning temperature can be secured. If, for example, the vat of cream shows 0.4% acid and the starter 0.7%, then one part of starter to two parts of cream would give an average acidity of 0.5%, the right amount for churning cream of moderate richness. Pumping Cream into the Churn. Cream may be forced into the churn either by means of air pumps, sanitary milk and cream pumps, or with pumps working on the principle of an ordinary well pump. The air pumps require air-tight cream ripeners for their successful operation. The air is pumped into the ripener to create sufficient pressure to force the cream into the churn. Forcing air into the ripener has the advantage of permitting the cream to be conducted to the churn through an open spout. Pumps worked with a handle have the advantage of 262 MARKET DAIRYING enabling the buttermaker to put his cream into the churn in the morning before there is sufficient steam pressure to work pumps with the engine. Fig. 54 shows a very satisfactory cream pump which Fig. 54.— Cream pump. can be made by any tinner. It simply consists of a heavy tin cylinder four inches in diameter which is provided with two brass valves having two inch openings. This pump is attached to the cream ripener and the cream pumped by hand into the churn through an open spout. Both valves can be removed so that there is not the slightest difficulty in cleaning the pump. Such a pump will readily pump 25 gallons of cream per minute. CHAPTER XXXIL MARKETING BUTTER AND CHEESE. PACKING BUTTER. Butter is usually in the best condition for packing immediately after it has been worked. It can then be packed solidly into the packages without the vigorous ramming necessary when the butter becomes too cold. When allowed to stand in the churn some time after work- ing during the warm summer days, the butter will usually get too soft for satisfactory packing. There is a great variety of packages in which butter may be packed for the markets. The bulk of the butter for home trade is packed in ash and spruce tubs, the former holding 20, 30, and 60 pounds, while the latter are made in 10, 20, 30, and 50 pound sizes. Before adding the butter, the tubs must be thoroughly scrubbed inside and outside, the hoops carefully set, and then soaked in hot water for about half an hour. After this they are steamed for three minutes and then allowed to soak in cold water not less than four hours. The sides and bottom of the tubs are next lined with parchment paper which has been soaked in strong brine for twenty- four hours. See "paraffining tubs," page 265. The wet liners are easily placed in the tubs by allowing them to project an inch and turning this over the edge. The tubs are now weighed and the butter packed into 263 264 MARKET DAIRYING them directly from the churn, adding about five pounds at a time and firmly packing it with a wooden packer made for this purpose. The butter should be packed solid so that when stripped of its package on the retailer's counter no open spaces will appear in it. When ash tubs are used they are packed brim full and trimmed off level with the tub by running a string across the top. The tubs are then weighed and the weights marked on the outside, allowing not less than half a pound for shrinkage for a sixty pound tub. A cheese cloth circle is next placed over the top and an oversatu- rated brine is pasted upon this. After careful cleaning place the covers on the tubs and fasten them with not less than three butter tub fasteners. With spruce tubs the method of packing is the same with the exception that most markets require an even number of pounds in a tub, as 30 or 50 pounds. The tubs are, therefore, trimmed down till the required weight, plus half a pound for shrinkage, is reached. Some markets do not require the spruce tubs to be lined but it is always better to do so. Prints. Considerable quantities of butter made in creameries are put up in one pound oblong blocks called prints. The prints are carefully wrapped in parchment paper which has been soaked in strong brine for twenty- four hours, and then packed in cheap wood boxes which usually hold about fifty of them. These boxes should be held not less than one day in a refrigerator before they are shipped. Print butter is growing in popularity. Other packages. There are various other packages in which butter is packed, such as five pound crocks, gem MARKETING BUTTER AND CHEESE 265 fibre paper boxes lined with parchment and holding 2, 3, 4, 5, and 10 pounds, and the wooden bail boxes holding from 5 to 10 pounds. Most of these packages are used for local trade. foreign Trade Packages. For export trade butter is preferably packed in cubical spruce boxes lined with paraffin and holding 56 pounds. These boxes are pre- pared by rinsing them with cold brine and then lining with parchment paper (double thickness at top and bot- tom) which has been soaked in brine. The boxes are now weighed and carefully packed, after which they are trimmed down to a weight of 57 pounds, which allows one pound for shrinkage. Finish the packing by placing a double thickness of parchment paper over the top and upon this oversaturated brine. Butter shipped to tropical countries is packed in tin cans which are hermetically sealed. Paraffining Butter Packages. During recent years buttermakers and butter dealers have suffered consider- able losses from moldy butter caused by the growth of mold on the liners and on the inside of the tubs. These losses can easily be avoided by resorting to the proper methods of destroying the mold. Rogers of the United States Department of Agriculture has shown that this trouble can be prevented with certainty by coating the inside of the tub with a layer of paraffin. He says: "With paraffining not only are the molds and their spores already on the tub prevented from growing but the wood is covered with a surface from which molds 266 MARKET DAIRYING can not get nourishment. The wood is made impervious to water, and the space between the tub and the liner remains filled with water, so that the molds which may be on the liner can not get the supply of air necessary to their growth." He has also shown that loss from shrinkage is largely prevented in this way. Testimonials from buttermakers indicate that the prac- tice of paraffining tubs is giving good satisfaction and many have already adopted it as a permanent feature in creamery work. To secure the best results from the paraffin, it should be applied at a temperature of about 240 F., immediately after steaming the tub. The steaming may or may not be preceded by soaking; under present conditions, how- ever, soaking is recommended, if for no other reason than to give tubs their full weight. 'Butter dealers are accustomed to handle soaked tubs and where they are not soaked, the creamery is liable to lose an amount of butter equal to the difference between the weights of the soaked and unsoaked tubs. Special machines are now upon the market for paraf- fining tubs. The paraffin may, however, be applied by pouring the same into the tub and rotating the latter until it is entirely coated. A brush may also be used for this purpose. Those who contemplate paraffining should in- vestigate' the merits of the machines now upon the market. Printing Cold Butter i Until recently the common practice has been to print butter directly from the churn. With the advent of the "cold" butter printers or cutters, much butter is being printed outside the creameries, and the latter are also adopting the practice of cooling the butter before printing. Cold butter makes better looking prints, MARKETING BUTTER AND CHEESE 267 injures the butter less, causes less water to be lost, facili- tates the wrapping, and makes it easier to pack the butter. The butter is preferably packed directly from the churn into square boxes of a size to fit the printer. Where butter is printed from tubs, there is too much butter left in irregular pieces, which are hard to repack and must be disposed of in bulk. MARKETING CREAMERY BUTTER. The producer of any commodity is always confronted with the problem of finding the best markets for his product. Indeed his success is measured more or less by his ability in handling this end of the business. Buttermakers lose thousands and thousands of dollars every year because they do not fully understand how to manage the sale of their product. They fall into the clutches of men without credit or credentials who offer big prices but no returns. Swindlers are always on the lookout for victims and every year many buttermakers are entrapped by them. To the one who is just beginning to seek a market for his butter the following course of procedure is recommended. i. Find the names of three or more leading reputable butter firms in the leading butter markets by inquiring of men from whom trustworthy information may be ex- pected. 2. Divide a day's standard make among these butter firms and instruct each to send you statement as to the price they can give you net (f. o. b.) at your station for regular shipments, the price to be based on quotations of some leading market. Inform them further that you are ready and willing to comply with their demands as to color, package, and salt, in future shipments. 268 MARKET DAIRYING 3. Ship your butter to the firm that offers you the best price, but do not deal with this firm exclusively. A tub should occasionally be sent to a new and reliable firm with a view to securing better prices. 4. Remember, however, that it requires time to estab- lish a good trade for butter. Frequent changes from one firm to another are therefore undesirable. 5. Do not sell butter on commission, but ask for prices f. o. b. your station, based on some market quotation like New York, Chicago or Elgin. 6. Demand that payment shall be made for each ship- ment of butter within two weeks after it is sent out. 7. Never send a firm a third shipment until the first has been paid for. 8. Butter that is not up to the standard should be marked and the firm properly instructed regarding its disposition. An attempt to crowd in an inferior ship- ment may cost you your regular trade. 9. Do not feel hurt when criticisms come regarding defects in your butter but seek to overcome them. 10. Always allow one-half pound of butter for shrink- age on fifty and sixty pound tubs. If this allowance proves inadequate it indicates that the tubs have not been properly soaked or that the "house" is cutting you on weights. 11. Never contract butter for more than a year at a time. How to Sell to Commission Houses. A common mistake in marketing butter is to sell it at prices based upon the score of the butter. This places the butter- maker at the mercy of the commission man who may, or may not, give an honest score. If he is not strictly honest he may easily place butter that would naturally grade as extras in the class of firsts, and butter MARKETING BUTTER AND CHEESE 269 that would naturally grade as firsts in the class of seconds. One of the best methods of selling butter to commis- sion houses is as follows: Furnish the buyer enough samples of butter to give him a good idea as to the aver- age quality of the butter produced by the creamery. An agreement can then be made as to the price the creamery shall receive for regular shipments, the price to be based upon some standard market quotation. If, for example, the buyer agrees that the quality of the butter merits one- half cent above Elgin, and the seller is satisfied with this price, future shipments shall be paid for at the rate of one-half cent above Elgin until such time as either party may become dissatisfied with the original agreement. If the butter maker feels that he is receiving a good price for his butter, he will do his best to maintain the standard of his product. Selling to Retailers and Wholesalers. Wherever pos- sible creameries should try to sell their butter direct to retailers and wholesale houses and in this way save the commission man's profits. This method of marketing, of course, necessitates visiting retailers and wholesalers in nearby cities, but this trouble will be more than compen- sated for by bringing the buttermaker in closer touch with the markets and with general market requirements. Branding Butter. As with hundreds of other com- modities, the branding of good butter is absolutely essen- tial in creating a strong demand for it. A high quality butter without a distinguishing mark is bound to sell at a disadvantage because consumers are not willing to pay high prices for products about whose quality they have no positive assurance. The brand advertises the butter and increases the demand for it, and an increased demand is always followed by better prices. 270 MARKET DAIRYING Floor plan of combined gathered cream and whole milk creamery. MARKETING BUTTER AXD CHEESE 271 MARKETING DAIRY BUTTER. For fancy trade, one-pound prints wrapped in parch- ment paper are the most popular. These prints are made with a small hand printer which should have the dairyman's monogram cut into it. The im- print of the monogram in the butter will serve as a guarantee of its genuineness. It is also desirable to have some neat letter- ing on the parchment wrapper, such, for ex- ample, as Fancy Dairy Butter, Cold Spring- Dairy Butter, Golden Jersey Butter, etc. Prints must be kept cold to preserve their attractive rectangular appearance. The best prices for butter are realized by selling it direct to the consumer. With milk dealers who retail milk and cream, this method of marketing not only yields the best prices, but is also the most convenient, because the butter can be disposed of at the same time as the milk and cream. A covered box like that shown in Fig. 55 is best adapted for carrying print butter to market. Ice may be packed in the box with the butter during warm weather. With the small butter producer the greatest trouble is finding a suitable market for his product. It is custom- ary with most of these producers to sell their butter to the country grocer, who, as a rule, makes little discrimi- Fig. 55.— Print Butter Box. 272 MARKET DAIRYING nation in the quality of the butter, the good and the poor selling for practically the same price. No producer of good butter can afford to market his butter in the coun- try stores. Those who have made farm butter making a success have invariably catered to private trade, or have sold their butter to well-known butter dealers. A great deal of butter could be sold in villages, towns, and cities at 25 and 30 cents a pound which would bring only 12 or 15 cents in the country stores. Seek, therefore, pri- vate customers who are willing to pay for a good product, and if these are not within easy reach by road, try to reach them by rail. MARKETING CHEESE. Cheddar Cheese. Most of the cheese is sold from the factory when from three to ten days old, Flats are shipped either single or two in a box ; in the former case they are known as "singles," in the latter as "twins." Young Americas and long horns are usually shipped four in a box. * One or two scale boards should be placed in the bot- tom of the box and on top of the cheese to protect the surface of the cheese. In the case of "twins," two scale boards should also be placed between the two cheese. The cheese boxes are cut down to about one-eighth of an inch below the top of the cheese. This enables the cover to rest securely on the cheese. About one-half pound overweight should be allowed on each box, the same as on butter tubs. The weight of the cheese must be plainly marked on the side of the box with a blue pencil or stencil. MARKETING BUTTER AND CHEESE 273 Cheese as a rule is sold on dairy boards of trade. In Wisconsin, most of the cheese is sold under the "call board" system, which is virtually equivalent to auction- ing off the cheese to the highest bidder. All the cheese makers and cheese buyers belonging to a particu- lar board meet as a rule once a week. At this time eacn cheese maker's offering of cheese is written on a black board, after which the buyers bid on the entries so made. The cheese maker usually sells to the highest bidder. Soft and Fancy Cheese. Cheese of a perishable na- ture, such as cottage, cream, club, pimento and Neufchatel, should be sold to the consumer as direct as possible. Milk dealers are in the best position to supply this cheese. Many are already supplying cheese of this kind to their customers at considerable profit. See chap- ters XV and XXL CHAPTER XXXIII. BUTTER OVERRUN. In a well conducted creamery the total pounds of but- ter made is always greater than the total pounds oi butter fat received; the difference is called the overrun. Thus, if during a certain time a creamery makes 2,400 pounds of butter from 2,000 pounds of butter fat, the overrun equals 2,400 less 2,000, or 400 pounds. The per cent of overrun is found by dividing the number of pounds of overrun by the total pounds of butter fat re- ceived and multiplying the quotient by 100. Putting this in the form of a formula, we have : Per cent ) pounds of overrun h X 100 Overrun [ total poun( | s of butter fat Where 2,000 pounds of butter fat will make 2,400 pounds of butter, the overrun will therefore equal : X 100, or 20%. 2000 A mistake not uncommonly made in calculating the per cent overrun is to divide the pounds of overrun by the total pounds of butter, instead of the total pounds of butter fat. FACTORS THAT INFLUENCE THE OVERRUN. It is well known that the overrun varies considerably at different creameries as well as at the same creamery. 274 BUTTER OVERRUN 275 The amount of overrun is directly dependent upon the following factors: 1. Efficiency of skimming and churning. 2. Composition of the butter. 3. Richness of milk and cream. 4. Mechanical losses. 5. Correct reading of tests. Efficiency of Skimming and Churning. It is evi- dent that the more fat there is lost in skimming and churning the lower will be the overrun. To obtain a maximum overrun, the loss of fat as shown by the Bab- cock test should not exceed 0.05 per cent for skim-milk and 0.15 per cent for buttermilk. In this connection it should be stated that during the summer season it is not at all uncommon to find butter- milk testing from 0.3 to 0.5 per cent, largely a result of employing too high a churning temperature. Composition of the Butter. Besides butter fat, butter contains water, curd and salt, and, other conditions the same, the greater the amount of non-fatty matter in butter the greater the overrun. Water, being present in large quantity and subject to considerable variation, very appreciably affects the percentage of overrun. There has been a tendency among creameries the past few years to manipulate butter so as to increase its normal water content and thereby increase the overrun. The water in butter easily fluctuates between 10 and 15 per cent, and a good overrun can be obtained by keep- ing it within the limits of 13 and 14 per cent. Salt as a rule has little influence on the per cent of overrun because under normal conditions an increase in 276 MARKET DAIRYING the amount of salt usually results in a decrease in the amount of water. Of course, where special methods of manipulating the water content are resorted to, it is possible to increase the overrun by increasing the amount of salt. Curd is present in butter in very small quantities, and its influence on the overrun is very slight. Richness of Milk and Cream. The test of skim-milk is practically independent of the richness of the milk — that is, other conditions the same, skim-milk from 2.5%' milk will test the same as that from 5 per cent milk. But since it takes twice as much 2.5 per cent milk to obtain 100 pounds of butter fat as is required with 5 per cent milk, it follows that the loss of fat in the skim-milk will be twice as great with the poorer milk. Assuming a loss of 0.05 per cent fat in the skim-milk, the loss of fat in the amount of milk needed to yield 100 pounds of butter fat is one pound greater for the poorer milk. The extra pound of fat thus lost would have made approximately 1.18 pounds of butter, so that the overrun from a 5 per cent milk may be expected to be approxi- mately 1. 1 8 per cent greater than that from milk testing 2.5 per cent. Rich cream yields a higher overrun than poor cream because of the smaller loss of fat in the buttermilk. That is, there is less buttermilk from rich cream than poor cream, and, since the per cent of butter fat in the butter- milk will be about the same in both cases, it follows that the loss will be greater from the poor cream, which yields the greater amount of buttermilk. Assuming a loss of 0.2 per cent of fat in the butter- milk, 100 pounds of butter fat in 35 per cent cream will BUTTER OVERRUN 277 yield about one-half pound more of butter than the same amount of fat in a 20 per cent cream ; in other words, the overrun from a 35 per cent cream will be one-half per cent greater than that from a 20 per cent cream. Mechanical Losses. By mechanical losses is meant the small losses of cream remaining in cans, vats, strain- ers, etc., and the butter particles remaining in the churns and on the packers, butter spades, etc. Where care is exercised in properly rinsing the cans and ripeners and in the handling of the butter, losses from this source will be rather slight. On the other hand, carelessness in these matters may result in heavy losses and in a material lowering of the overrun. Correct Reading of Tests. It is very evident that a little too high or a little too low a reading will mate- rially affect the overrun. If a cream whose actual test is 30 per cent should be read only 29 per cent, the overrun will be abnormally increased by approximately 4.0 per cent. It is easy to make a mistake of one per cent in the reading of cream tests and, what is worse, many cream tests are purposely read too low so as to enable the creameryman to show a big overrun. It is to every creameryman's interest to read tests accurately, because inaccuracies are bound to be discovered sooner or later and may lead to the disruption of the creamery. Average Overrun. The overrun from whole milk averages 18%, that from cream 20%. CHAPTER XXXIV. CHEDDAR CHEESE MAKING. Ripening the Milk. As soon as the milk has been placed in the cheese vat, a test is made for acidity, pref- erably by means of acid tests such as are described in chapter IX. If less than 0.2% acid is present, starter should be added. Starter improves the flavor of cheese just as it improves the flavor of butter. One to one and one-half pounds of starter per 100 pounds milk is a fair allowance for average cheese factory milk. The starter should always be strained through cheese cloth before adding it to the milk. After the starter has been added, the milk should be heated to a temperature of 86° F. and allowed to ripen until 0.2 per cent acid is present. While holding the milk for acid development, it should be frequently stirred to keep the cream mixed with the milk. A temperature of 86° F. must be maintained during the ripening pro- cess. Adding Color and Rennet. When the milk shows 0.2 per cent acid, color is added at the rate of about one ounce per thousand pounds of milk. The amount of color to use, however, depends upon market demands, some markets preferring no color at all. The color should be diluted with about four times its volume of water to aid in mixing it with the milk. Imperfect mix- ing results in mottled cheese. 278 CHEDDAR CHEESE MAKING 279 After the color is thoroughly incorporated, add ren- net extract at the rate of about three and one-half ounces per 1,000 pounds of milk. The rennet extract should be diluted with water to the extent of at least five times its own volume before adding it to the milk. After the rennet extract has been thoroughly stirred in, the milk should be allowed to stand undisturbed until sufficiently curdled to cut. The temperature at the time of adding the rennet should be 86° F. The amount of rennet extract to be used is determined by the quickness with which the cheese is to ripen. If a quick ripening cheese is wanted, add about 4 ounces per 1,000 pounds of milk. If a slow ripening cheese is de- sired, add 2y 2 to 3 ounces per 1,000 pounds. While the milk is curdling it must be kept well cov- ered to keep the surface layer warm. Cutting the Curd. To determine when the curd is ready to cut insert the forefinger, slightly break the curd with the thumb, and move the finger in the direction of the break and parallel to, and half an inch below, the surface. If the whey in the break is clear, the curd is ready to cut; if milky, the curdling has not progressed far enough. The cutting is done as follows: First cut the curd in horizontal layers with the horizontal knife; next cut lengthwise and crosswise, alternately, with the perpendicular knife until the curd cubes are about three- eighths of an inch on a side. Warming and Stirring the Curd. Immediately after cutting, stir the curd very gently, yet enough to prevent the particles from matting together. Run the palm of the hand along the sides and bottom of the vat to remove any adhering curd. After 10 minutes stirring, gradually apply heat and raise the temperature to between 98 and 280 MARKET DAIRYING ioo° F. in about 30 to 45 minutes. After this temper- ature has been reached, the curd may be stirred at inter- vals of 10 minutes until ready to remove the whey. It is important to keep the temperature close to ioo° F. Drawing Off the Whey. When a bunch of curd is pressed between the two hands and on relieving the pres- sure the particles fall apart readily, the curd is ready for the removal of the whey. When this firmness is reached, the whey should show 0,17 to 0.18 per cent acid. When the milk is set at the proper ripeness, the degree of firm- ness and amount of acid indicated above are reached in two and one-half to three hours after adding the rennet extract. Remove the whey through a faucet or by means of a siphon. Place perforated wooden racks, about two inches high, at one end of the vat and cover them with a piece of muslin or French crash. Scoop the curd upon the racks, which have the advantage of draining the curd quickly and also permits the use of hot water under the curd to assist in keeping the temperature at 98 F., a tempera- ture which should be maintained up to within a short time of salting. Piling and Matting the Curd. As soon as removed from the whey, the curd is stirred a few minutes, spread about six inches deep upon the racks and then allowed to mat 15 minutes, after which it is cut into strips about 8 by 12 inches and then turned. After another 15 min- utes, turn again and pile the strips two layers deep; 15 minutes later turn again and pile three layers deep. Usually after one and a half to two hours matting the curd tears like chicken breast, which indicates that it is ready to mill. During the entire matting process the curd should be kept at a temperature of 98 F. CHEDDAR CHEESE MAKING 281 Milling. When properly matted the curd is run through a cnrd mill, which will cut the curd into strips about the size of a ringer. This treatment makes possible a ready absorption of the salt by the curd. Salting. After milling the curd is stirred frequently until it becomes mellow and velvety to the touch, when it is ready to salt. At this time the whey exuding from the curd should show about one per cent acid. With normally working curds, salt can usually be added about one hour after milling. Tainted curds require more time. If a fast-curing cheese is desired, salt at the rate of 2^4 pounds of salt per ioo pounds of curd. When a slow-ripening cheese is desired salt at the rate of 2^4 pounds. Use only the best grade of salt, and have the curd at a temperature of about 90 F. at the time of salting. The salt must be evenly mixed with the curd to ensure uniformity of color and quality in the cheese. Molding and Pressing. When the curd has become soft and mellow, which usually requires from 20 to 30 minutes, the curd is ready for the hoops (molds) which are prepared as follows: Place a piece of muslin in the bottom of the hoop and on top of this a cheese cloth circle somewhat less in diameter than the hoop. Now place the bandage on the bandager so that when the latter is in position the bandage will lap slightly over the cheese cloth circle in the bottom of the hoop. Next put in the curd. This done, cover the curd with a piece of muslin and put on the cover (follower). Apply pressure very gradually at the start and do not apply full pressure (about 20 lbs. to the square inch) until after 20 to 30 minutes' pressing. Shortly after full pressure has been applied, remove the follower, the muslin cloth and bandager. Turn the projecting bandage over onto the 282 MARKET DAIRYING cheese. Next place a cloth circle over the top, replace the muslin and bandager, and then apply full pressure for about 12 hours. The cheese is now taken out of the hoop, any folds or irregularities in the bandage straightened out, and then washed off with hot water and put back into the hoop inverted. Press about ten hours longer and remove the cheese from the hoop and put it into a suitable place for curing. Remove the mus- lin cloths but leave the cheese cloth circles on the cheese. Ripening or Curing. After leaving the press the cheese should be placed in a cool, damp room with ample ventilation. Keep the temperature of the curing room at 6o° F. or below. The curing or ripening process, which consists of the transformation of insoluble into soluble casein, requires from two to eight months, accord- ing to the amount of rennet extract and salt used, amount of moisture in the cheese and the temperature at which it is ripened. The higher the temperature and moisture, the quicker the cheese will ripen. During the first two weeks the cheese should be turned and rubbed daily, and if any portion of it is not covered with cheese cloth, grease should be applied to prevent cracking. The Value of Low Curing Temperatures. A subject which deserves more attention than has heretofore been given it is the value of cold storage in connection with cheese factories. Many factories are already thus equip- ped and the general opinion of the owners of these factor- ies is that the advantages afforded return very good inter- est on the money invested. The chief advantages afforded by cold storage are less shrinkage and a better quality of cheese. Experiments have shown that with cheese weighing about 65 pounds, the shrinkage during the first week, CHEDDAR CHEESE MAKING 283 when the cheese is kept at 55 ° F., is 1.6 pounds per hun- dred pounds of cheese. At 8o° F. the shrinkage is 2.4 pounds per hundred, an increase of 50 per cent. With small cheese weighing 9 pounds, the shrinkage is about 40 per cent greater than with cheese weighing 65 pounds. Since the temperature in the majority of curing rooms averages about 8o° F. during July and August, a factory making cheese weighing 9 pounds and averaging 600 pounds per day will effect a saving of 6.72 pounds by curing the cheese the first week at 55 ° F. instead of 8o° F. At 14 cents per pound the saving amounts to 94 cents a day. What is of still greater significance than the saving in shrinkage, is the general improvement in the quality of cheese cured at low temperature. Temperatures be- tween 50 and 6o° F. will produce very satisfactory re- sults. Paraffining Cheese. To prevent molding and ex- cessive loss of moisture in curing cheese in the average curing room, cheese should be paraffined about three days after it leaves the press or as soon as the rind has become thoroughly dry. The paraffining is done by im- mersing the cheese for about five seconds in paraffin hav- ing a temperature of at least 220 F., and 240 F. is better. GASSY MILK. Gassy milk causes cheesemakers a great deal of trou- ble, especially during the hot summer months. Gassy curds and floating curds have always been among the cheesemaker's greatest troubles. During hot weather the gas producing bacteria predominate over the other unde- sirable kinds and under certain conditions they predom- 284 MARKET DAIRYING inate over the lactic acid kind. It is under the latter condition that the gassy curds result. Preventive Measures. The trouble from gas organ- isms can almost entirely be overcome by instructing the patrons to cool their milk thoroughly and by the use of a good lactic acid starter. The cooling of the milk holds the gas producing bacteria in check and will give the cheesemaker milk sweet enough to enable him to use a reasonable amount of starter. In many cheese factories, during warm weather, the milk arrives at the factory too ripe to permit the use of starter. Where this is the case a high quality cheese is hardly possible. If there is no trouble from gas organ- isms there are usually other taints present. The use of one pound of good starter to every ioo pounds of milk will almost entirely eliminate trouble from gas germs and will also eliminate taints that are likely to develop where no starter is added. Where the sweetness of the milk permits, it is desirable to use more starter but care must be taken not to overripen the milk with too much starter which might result in an acidy or sour cheese ; but at least one-half pound to the hundred pounds of milk should always be used. Handling Gassy Curds. A good starter is the best means of combating gas-producing bacteria. The latter cannot survive in the presence of a large number of lac- tic acid organisms. Every cheesemaker knows that gassy milk ripens slowly and this is so because the gas organ- isms seriously hamper the development of the acid bac- teria. It is for this reason that milk that is known to be gassy should be ripened further before adding the rennet than normal milk. Also more acid should be developed in the whey than with normal curds. CHEDDAR CHEESE MAKING 285 While the curd is matting on the racks, the tempera- ture should be kept close to 98 F. and this temperature should be maintained close up to salting. The curd after cutting should be kept well stirred and the salting delayed until the gas holes have thoroughly flattened or practically disappeared. At this stage the curd will be very mellow and greasy, a condition favoring a close tex- tured cheese from gassy milk. After salting the curd should also be kept well stirred and allowed to become mellow and velvety before going to press. Where curds show gas day after day a curd test should be made of each patron's milk to locate the source of trouble. Directions for making a curd test are given on page 191. HANDLING OVERRIPE MILK. When milk is overripe, set at a little higher tempera- ture, add a little more rennet, cut the curd a trifle softer than usual and cut finer. By cutting the curd twice as fine as usual it can be firmed up in practically one-half the usual time. Heat faster than usual. Curd that is cut fine cannot easily be injured by fast heating. In heating fast, however, greater care must be exercised in preventing the curd from getting lumpy. Heat the curd to a higher temperature than usual — up to 106 F. in badly overripe milk. Remove a portion of the whey as soon as possible; this materially checks the development of acid. Stir the curd constantly. If rather soft at dipping time, stir upon racks until firm. Do not develop more than the usual amount of acid in the whey. It is better to dip the curd soft rather than to hold it till firm and develop too much acid. If the curd is rather soft when placed on the racks 286 MARKET DAIRYING and the acid appears to develop fast, do not pack the curd deep but turn it frequently and keep the tem- perature close to 98 ° F\ Pouring clean, warm water over the curd right after it is placed on the racks, will ma- terially check the development of acid. Mill rather early and when the proper amount of acid has been reached, salt. If the curd is rather soft and moist at this time use an extra amount of salt and hold the curd longer than usual after salting. ORAINAGE OISPOSAL^JSEPTIC TANKS OR CCSS-POOL ICF HOUSE WHEY TANKS o CURING SHELVES COAL A WOOD BOILER ROOM I 00! I WASH WEIGH c WtIDH o J Jorricc Floor Plan of Cheese Factory. (From "Science and Practice of Cheese Making.") CHAPTER XXXV. CREAMERY AND FACTORY DIVIDENDS. CREAMERY DIVIDENDS. Milk and cream yield butter in proportion to their butter fat content. That is the reason why practically all milk and cream made into butter are now bought by the "Babcock test," that is, on the "butter fat basis." In discussing the method of paying for milk and cream, therefore, only the "butter fat basis" will be considered. The periodical payments made for milk and cream at creameries are known as creamery dividends. These pay- ments or dividends are sometimes made daily, as in the case of some gathered cream plants ; more often, how- ever, they are made weekly, semi-monthly and even monthly. The different steps in the calculation of dividends at creameries are as follows: First, find' the total pounds of butter fat received from all the patrons. This is done by finding the total amount of butter fat furnished by each patron separately and adding together the totals so found. In finding each patron's total butter fat, every delivery of cream is mul- tiplied by its test and the results of the different deliv- eries added together. Second, find the net money from the sale of butter by multiplying each sale of butter by its price and deducting from the amount thus found the cost of making the butter. Third, find the price per pound of butter fat by divid- 287 288 " MARKET DAIRYING ing the total net money by the total pounds of butter fat delivered by all the patrons. Fourth, find each patron's share of the money by mul- tiplying the total pounds of butter fat delivered by him by the price per pound of butter fat. To make the above steps perfectly clear, let us cal- culate a weekly dividend at a creamery where only cream is received and where A, B and C are the patrons : Illustrating the First Step. The total butter fat de- livered by A, B and C is as follows : Pounds Pounds of of cream. Test. butter fat. May 2 42 X 35.4 = 14.87 May 4 50 X 30.1 = 15.05 May 6 48 X 30.5 = 14.64 May 7 20 X 36.6 = 7.32 -{ Total 51.88 {May 2 May 4 May 6 May 7 23 X 40.5 = . 9-32 4 29 X 30 . o = 8 . 00 6 25 X 36.4 = 9.10 13 X 35.0 = 4-55 Total , 30.97 May 2 64 X 33.0 = 21.T2 C 1 May 4 69 X 31. 1 = 21.46 May 6 58 X 37.5 = 21.75 May 7 30 X 34.4 = 10.32 I Total 74-65 The total butter fat delivered by A, B and C equals 51.88 + 30.97 + 74.63 equals 157-48 pounds. Illustrating the Second Step. The net money is found as follows: CALCULATING DIVIDENDS 289 Pounds of Price per butter sold, pound. Amount. May 3 86 X 26^c = $22.79 May 7 103 X 26c = 26. 78 Total lbs. butter 189 Total money $49-57 At 33^2 cents a pound for making, the cost of manu- facture will be 3>4 X 189, or $6.62. Deducting this amount from the total money, there remains $42.95, which is the total net money due the patrons. Illustrating the Third Step. The price per pound of butter fat is obtained by dividing the total net money found in step two by the total pounds of butter fat found in step one. Thus: $42.95-^-157.48 = 27.27 cents = price per pound of butter fat. Illustrating the Fourth Step. Find the money due each patron by multiplying the butter fat furnished by him as determined in step one by the price per pound of butter fat as determined in step three. Thus: 51.88 X $.2727 = $14.15 = A's money. 30.97 X .2727 = 8.44 = B's money. 74.65 X .2727 = 20.36 = C's money. WHERE WHOLE MILK IS RECEIVED. The method of calculating dividends at whole milk creameries is the same as that at hand separator creamer- ies except that a test is not made of each delivery of milk. Where whole milk is received a composite sample is made of each patron's milk ; that is, each patron is provided with a pint jar to which samples of his milk are added daily for one or two weeks when the composite sample is tested. A test of the composite sample represents the 290 MARKET DAIRYING - average per cent of butter fat in the milk for the period during which the sample was gathered. The method of composite sampling employed by whole milk creameries is also used to some extent at hand sepa- rator creameries, but unless the cream is delivered in a fine, sweet condition, sufficiently accurate results cannot be obtained with this method. Usually hand separator cream is delivered in a more or less sour condition which does not permit of composite sampling. The fact that the deliveries of cream vary considerably in quantity and richness is a further reason why the composite method of testing cream is liable to lead to inaccurate results. WHERE BOTH MILK AND CREAM ARE RECEIVED. The calculation of dividends at creameries receiving both milk and cream differs from the method used where only milk or cream is received in that allowance must be made for the fat lost in the milk skimmed at the creamery. On an average 2 per cent of the total fat of milk is lost in the skimming process. Hence, if cream patrons are credited with all the fat they bring in the cream, it will be neces- sary to deduct 2 per cent of the fat brought in the milk by the whole milk patrons, which represents the amount carried home by them in the skimmed milk. Heretofore most creameries have equalized the pay- ment for milk and cream by increasing the butter fat from cream patrons by 2 per cent, which, so far as dol- lars and cents are concerned, will have the same effect as deducting 2 per cent from the fat delivered by whole milk patrons. The latter method, however, results in a greater overrun and therefore in a greater price per pound of butter fat. In order, therefore, to put cream- CALCULATING DIVIDENDS 291 eries receiving both whole milk and cream on a par with those receiving only cream, so far as overrun and price per pound of fat is concerned, it will be necessary to deduct 2 per cent from the fat delivered by whole milk patrons and not, as commonly done, add 2 per cent to the fat delivered by cream patrons. The following example illustrates how milk and cream patrons are credited with butter fat in making dividends at creameries receiving both milk and cream: Patron A delivers 6,500 pounds of milk testing 4.0 per cent. Patron B delivers 600 pounds of cream testing 30 per cent. A's total fat = 6,500 X .04 = 260 pounds. B's total fat = 600 X .30=180 pounds. To decrease A's fat by 2 per cent, multiply 260, the total pounds of fat furnished in his milk, by .98, which equals 254.8. In making the dividend, therefore, A is paid for 254.8 pounds of fat and B for 180 pounds. THE TWO PER CENT — HOW CALCULATED. In a well conducted creamery the average loss of fat in the skim-milk should not be more than .078%. Di- viding this figure by the average percentage of fat in milk, 3.9, we get .02. So that in the separating process* .02 pound of fat is lost in the skim-milk for every pound of fat present in the milk. From the above calculation it will be seen that the cream factor (2%) would necessarily vary with the efficiency of skimming and the average test of the milk. To determine what this shall be for any particular cream- ery divide the average loss of fat in the skim-milk by the average test of the milk at the creamery. 292 MARKET DAIRYING METHODS OE PAYING FOR MILK AND CREAM. While practically all creameries buy milk or cream ac- cording to the amount of fat contained in it, the method of paying for same varies with different creameries. With proprietary whole milk creameries, the usual custom has been to guarantee patrons a certain price for butter based upon some leading market quotation and charge a fixed price for making the butter, say 3^ cents per pound. All of the butter made belongs to the patrons. Cooperative creameries, as a rule, pay for butter fat according to the net returns from the creamery; that is, they deduct from the total gross returns the actual cost of making the butter, plus a small sinking fund, and di- vide the balance on the basis of the amount of butter fat furnished by each. Many hand separator creameries, and most of the cen- tralizers, pay for butter fat according to market quota- tions on butter. The price paid averages, as a rule, from one to three cents below the average market price for butter, transportation charges being paid by the creamery. AVERAGING TESTS. In whole milk creameries, where the amount of milk delivered from day to day and the tests of the same vary but slightly, reasonably accurate results may be obtained by averaging two composite tests, each representing, ( say, one week's milk. With cream the matter is different. Cream deliveries from the same patron vary considerably in quantity and quality and hence averaging cream tests is almost certain to lead to fallacious results, as may be seen from the following example: CALCULATING DIVIDENDS 293 The quantity and quality of cream delivered by a cer- tain patron for three days is as follows : Date. Lbs. cream. Per cent fat. May i 33 40. 5 May 2 48 30.0 May 3 55 28.5 136 3)99.0 Wrpng average test = 33-0 Wrong total fat — 136 X 33 = 44.88 lbs. The correct average test is obtained by multiplying each delivery of cream by its test and dividing the total butter fat thus found by the total number of pounds of cream and multiplying the quotient by 100. Thus: Lbs. cream. Per cent fat. Lbs. fat. 33 40.5 I3-36 48 30.0 14.40 v 55 28.5 15.68 ' 136 43-44 Correct average test = (43.44 -5- 136) X 100 = 31.94%. Correct total fat — 43.44. CREAMERY STATEMENT. When the monthly or weekly payment is made, each patron is presented with an envelope upon which is printed his individual account with the creamery and also the entire transactions of the creamery. A check on the nearest bank, or the money, is placed in the envelope and handed to the patron on "pay day." Such a state- ment is shown on the next page. 294 MARKET DAIRYING Cre amery Co. IN ACCOUNT WITH Mr. For the mc mth of 1QO No. lbs. milk by you, Average test, No. lbs. of but Price per lb. Cr. delivered Lbs. butter. Dr. ..© Cash, Hauling, @. per 100 lbs. - ter f at, ... , $ $ Balance due you, Total lbs. milk delivered at creamery, - Average test at creamery, Total lbs. of Butter fat at creamerv. = $ a Sales r ibs. i i* <« 3 Of H «< Butter. ing. a s s S Less Balance due Per cent, ov Testing wit cts. for mak patrons, errun nessed by PresL Sec'y. CALCULATING DIVIDENDS 295 FACTORY DIVIDENDS. The different steps in calculating dividends at cheese factories are as follows: First find the total butterfat delivered by all the patrons. Let us suppose that during the first week of April Patron A delivered 700 pounds of milk testing 3.6% fat. 7. 00X 3-6=25. 2=number of pounds of fat in the 700 pounds of A's milk. Let ns suppose that during the same period Patron B delivered 36.5 pounds of fat and Patron C 42 pounds. The total fat furnished by the three patrons is 25.2+36.5-J-42. or 103.7 pounds. Having found the number of pounds of fat delivered, next find the net amount of money due the patrons. By referring to the sales book we find that the 103.7 pounds of fat made 270 pounds of cheese, which was sold at 18 cents per pound. 27oX$.i&=$48.6o, the total money re- ceived for the 270 pounds of cheese. We will suppose that 1 24c was charged for making. The total charge for making. would be 270X1 H c > or $4-7 2 - Subtracting this from the total money, we have $43.88, which is the net money due the patrons. Next find the price per pound of fat by dividing the total net money by the total pounds of fat, thus: $43.88 -f-i03.7=$423i=price per pound of fat. Now we find each patron's share of the money by mul- tiplying his fat by the price per pound of fat. Thus: A's money=25.2X$-423i=$io.66 B's money=36.5X 4231= 1544 C's money=42.oX 4 2 3i= l 7-77 CHAPTER XXXVI. MECHANICAL REFRIGERATION. In warm climates and in localities where ice is not obtainable or only so at a high cost, cold may be produced by artificial means known as mechanical refrigeration. This system of refrigeration is also finding its way into creameries that are able to procure ice at a moderate cost but which are seeking more satisfactory means of control- ling the temperature of their cream, refrigerator, make room, etc. Refrigerating Machines. There are four kinds of machines used for refrigerating purposes: (i) vacuum machines in which water is used as the refrigerating medium; (2) absorption machines in which a liquid of a low boiling point is used as the refrigerating medium, the vapors being absorbed by water and again separated from it by distillation 5(3) compression machines which operate practically the same as the absorption machines except that the vapors in this case are compressed instead of absorbed; and (4) mixed absorption and compression ma- chines. Most of the machines in use at the present time belong to the compression type ; the following discussion will therefore confine itself strictly to this class of machines. Principle. The principle employed in mechanical re- frigeration is the production of cold by the evaporation of liquids which have a low boiling point, like liquid ammonia, liquid carbonic acid, ether, etc. 296 MECHANICAL REFRIGERATION 297 Fig. 56.— Showing circulation of ammonia in mechanical refrigeration. 298 MARKET DAIRYING When a liquid evaporates or changes into the gaseous state it absorbs a definite amount of heat called heat of vaporization or ''latent" heat. Thus to change water from 212° F. to steam at 21 2° F. requires a considerable amount of heat which is apparently lost, hence the term latent (hidden) heat. Ether changes into its gas at a much lower temperature than water which is illustrated by its instant evaporation when poured upon the hand. The heat of the hand in this case is sufficient to cause vaporization and the sensation of cold indicates that a certain amount of heat has been abstracted from the hand in the process. Manifestly for refrigerating purposes a liquid must be used that can be evaporated at a very low temperature; for the cold in mechanical refrigeration is produced, by the evaporation of the liquid in iron pipes, the heat for the purpose being absorbed from the room in which the pipes are laid. Anhydrous ammonia has thus far proven to be the best refrigerant for ordinary refrigeration. Anhydrous Ammonia (Refrigerant). This substance is a gas at ordinary temperatures but liquifies at 30 F. under one atmospheric pressure. In practical refrigera- tion the ammonia is liquified at rather high temperatures by subjecting it to pressure. The ammonia is alternately evaporated and liquified so that it may be used over and over again almost indefinitely^ Circulation of Ammonia. The cycle of operations in mechanical refrigeration is as follows: The liquid am- monia starts on its course from a liquid receiver, and enters the refrigerating coils in which it evaporates, ab- sorbing a large amount of heat in the process. By means of a compression pump, operated by an engine, the am- monia vapors are forced in the condenser coils where the MECHANICAL REFRIGERATION 299 ammonia, under pressure, is again liquified by running cold water over the coils. From the condenser coils it enters the liquid receiver, thence again on its journey through the refrigerating coils. The intensity of refrigeration is regulated by an ex- pansion valve, which is placed between the liquid receiver and the refrigerating coils. This valve may be adjusted so as to admit the desired quantity of liquid ammonia to the coils. Systems of Refrigeration. There are two ways in which the cooling may be accomplished by mechanical refrigeration: (i) by evaporating the liquid ammonia in a series of pipes placed in the room to be refrigerated ; and (2) by evaporating the liquid ammonia in a series of coils laid in a tank of brine and forcing the cold brine into coils laid in the room to be refrigerated. The former is known as the direct expansion system, the latter as the indirect expansion or brine system. Brine System. In creameries where the machinery is run only five or six hours a day the brine system is the more satisfactory as it permits the storing of a large amount of cold in the brine, which may be drawn upon when the machinery is not running. The brine tank is preferably located near the ceiling in the refrigerator where it will serve practically the same purpose as an overhead ice box. In addition to this, the refrigerator should contain a coil of direct expansion pipes which may be used when extra cold is desired. Brine from the above tank may be used for cooling cream by conducting it through coils which are movable in the cream vat ; it may also be conducted through sta- tionary pipes placed in the make room for the purpose 300 MARKET DAIRYING of controlling the temperature during the warm summer months. The brine is kept circulating by means of a brine pump. Strength of Brine. The brine is usually made from common salt (sodium chloride). The stronger the brine the lower the temperature at which it will freeze. Its strength should be determined by the lowest temperature to be carried in the brine tank. The following table from Siebel shows the freezing temperature as well as the specific heat of brine of different strengths: Percentage oi salt by weight. Pounds of salt per gallon of solution. Freezing point (F.). Specific heat. 1 0.084 0.169 0.256 0.344 0.523 0.708 0.897 1.092 1.389 1.928 2.488 2.610 30.5 29.3 27.8 26.3 23.9 21.2 18.7 16.0 12.2 . 6.1 0.5 -1.1 .992 2 .984 3 .976 4 .968 6 .946 8 .919 10 .892 12 .874 15 .855 20 .829 25 .783 26 .771 The fact that the specific heat grows less as the brine becomes stronger shows it to be wise not to have the solution stronger than necessary, because the less the specific heat the less heat a given amount of brine is able to take up. Refrigerating Capacity. When speaking of a machine of one ton refrigerating capacity, we mean that it will produce, in the course of twenty-four hours, the amount of cold that would be given off by one ton of ice at 32 ° F. MECHANICAL REFRIGERATION 301 melting into water at the same temperature. Its actual ice making capacity is usually about 50% less. Size of Compressor. In a moderately well insulated creamery handling from twenty to twenty-five thousand pounds of milk daily, a four-ton compressor will be large enough. With a compressor of this size the machinery will not have to be run more than five or six hours a day. If the machinery is run longer than this a smaller com- pressor will do the work. Power Required to Operate. The power required per ton of refrigeration is less the larger the machine. With a four-ton compressor the power required is from two to two and one-half horse power per ton of refrigerating capacity in twenty-four hours. Refrigerating Pipes. The refrigerating pipes vary from one 'to two inches in diameter. With moderately good insulation it is estimated that by the direct expansion system one running foot of two-inch piping will keep a room of forty cubic feet content at a temperature of 32 ° F. With brine nearly twice this amount of piping would be necessary. For cooling the brine in the brine tank, about 140 feet of 1 % -inch pipes are required per ton of refrigerating capacity. Expense of Operating. When a refrigerating plant has once been installed and charged with the necessary ammonia, the principal expense connected with it will be the power required to operate the compressor. This power in a creamery is supplied by the creamery engine. The ammonia, being used over and over again, will add but a trifle to the running expenses. Nor can the water used for cooling the ammonia vapors add much to the cost of operating. It is true, however, that the refrigera- 302 MARKET DAIRYING ting plant will require some of the butter maker's time and attention, but this is probably no more than would be consumed in the handling of ice in the creamery. Charging and Operating an Ammonia Plant. This subject is so ably discussed in The Engineer by H. H. Kelley that the author feels he can do no better than present the following extracts from that article. "When about to start an ice or refrigerating plant, the first thing necessary is to see that the system is charged with the proper amount of ammonia. Before the ammonia is put in, however, all air and moisture must be removed ; otherwise the efficiency of the system will be seriously interfered with. Special valves are usually provided for discharging the air, which is removed from the system by starting the compressor and pumping the air out, the operation of the gas cylinder being just the reverse of that when it is working ammonia gas. It is practically impos- sible to get all the air out of the entire system by this means, so that some other course must be taken to remove any remaining air after the compressor has been started at regular work. This can be accomplished by admitting the ammonia a little at a time, permitting the air to escape through a purge valve, the air being thus expelled by dis- placement. The cylinder containing the anhydrous am- monia is connected to the charging valve by a suitable pipe, and the valve opened. The compressor is then kept running slowly with the suction and discharge valves wide open and the expansion valve closed. When one cylinder is emptied put another in its place, being careful to close the charging valve before attempting to remove the empty cylinder, opening it when the fresh cylinder is connected up. "From sixty to seventy-five per cent of the full charge is MECHANICAL REFRIGERATION 393 sufficient to start with so that the air may have an oppor- tunity of escaping with as little loss of ammonia as possi- ble. An additional quantity of ammonia may then be put in each day until the full charge has been introduced. When the ammonia cylinders have been emptied and a charge of, say, seventy-five per cent of the full amount has been introduced, the charging valve is closed and the ex- pansion valve opened. The glass gauge on the ammonia receiver will indicate the depth of ammonia. The appear- ance of frost on the pipe leading to the coils and the cooling of the brine in the tank will indicate that enough ammonia has been introduced to start with. It is some- times difficult to completely empty an ammonia cylinder without first applying heat. The process of cooling being the same when the ammonia expands from the cylinder into the system as when leaving the expansion valve, a low temperature is produced and the cylinder and con- nections become covered with frost. When this occurs the cylinder must be slightly warmed in order to be able to get all the ammonia out of it. The ammonia cylinders, when filled,' should never be subjected to rough handling and are preferably kept in a cool place free from any lia- bility to accident. The fact that ammonia is soluble in water should be well understood by persons charging a refrigerating system, or working about the plant. One part of water will absorb about 800 parts of ammonia gas and in case of accident to the ammonia piping or machine, water should be employed to absorb the escaping gas. Persons employed about a plant of this kind should be provided with some style of respirator, the simplest form of which is a wet cloth held over the mouth and nose. "After starting the compressor at the proper speed and adjusting the regulating valve note the temperature of 304 MARKET DAIRYING the delivery pipe, and if there is a tendency to heat open it wider, and vice versa. This valve should be carefully regulated until the temperature of the delivery pipe is practically the same as the water discharged from the ammonia condenser. With too light a charge of am- monia the delivery pipe will become heated even when the regulating valve is wide open. As a general thing when the plant is working properly the temperature of the refrigerator is about 15 lower than the brine being used, the temperature of the water discharged from the ammonia condenser will be about 15 lower than that of the condenser, the pointers on the gauges will vibrate the same distance at each stroke of the compressor and the frost on the pipes entering and leaving the refrigerator will be about the same. By placing the ear close to the expansion valve the ammonia can be heard passing through it, the sound being uniform and continuous when everything is working properly. "When air is present the flow of ammonia will be more or less intermittent, which irregularity is generally notice- able through a change in the usual sound heard at the ex- pansion valve. The pressure in the condenser will also be higher and the effect of the apparatus as a whole will be changed, and, of course, not so good. These changes will be quickly noticed by a person accustomed to the conditions obtaining when everything is in order and working properly. "The removal of air is accomplished in practically the same manner as when charging the system, permitting it to escape through the purging valve a little at a time so as not to lose any more gas than is absolutely necessary. "The presence of oil or water in the system is generally detected by shocks occurring in the compressor cylinder. MECHANICAL' REFRIGERATION 305 "In nearly all plants the presence of oil in the system of piping is unavoidable. The oil used for lubricating pur- poses, especially at the piston rod stuffing boxes, works into the cylinders and is carried with the hot gas into the ammonia piping, where it never fails to cause trouble. The method of removing the air from the system has already been referred to, but the removal of oil is accomp- lished by means of an oil separator. This is placed in the main pipe between the compressor and the condenser, and is of about the size of the ammonia receiver. Some- times another oil separator is placed in the return pipe close to the compressor, which serves to eliminate any remaining oil in the warmer gas and to remove pieces of scale and other foreign matter which, if permitted to enter the compressor cylinder, would tend to destroy it in a very short time. "The oil, which always gets into the system sooner or later and in greater or less quantity, depending upon the care exercised to avoid it, acts as an insulator and pre- vents the rapid transfer of heat from the ammonia to the pipe that ought to obtain, and also occupies considerable space that is required for the ammonia where the best re- sults are to be obtained." CHAPTER XXXVII. WASHING AND STERILIZING MILK VESSELS. Wash Sinks. A matter of importance in washing milk vessels is to have the right kind of sinks, three of which are needed for the most satisfactory work: One Fig. 57.— Wash Sinks. for rinsing before washing, one for washing and one for final rinsing. For convenience the wash sink should be thirty-six 306 WASHING AND STERILIZING 307 inches long, twelve inches deep, and sixteen inches wide. The bottom should be round and two feet from the floor. When closer to the floor than this too much stooping is required. Milk Bottle Brush. A Good Cleaning Brush. Galvanized iron furnishes one of the most suitable ma- terials for the construction of wash sinks. They should be provided with steam (or hot water) and cold water pipes as shown in Fig. 57. Method of Washing. All vessels should be thor- oughly rinsed in warm water to re- move small residues of milk and cream. The rinsing is fol- lowed by washing with moderately hot water to which a handful of some cleaning powder has been added. The washing should be done with brushes rather than cloths be- cause the bristles en- ... Fig. 58.— Bottle Washer. ter into crevices which a cloth could not possibly reach. Finally rinse the vessels in clean water. A bottle washer, like that shown in Fig. 58, saves much 308 MARKET DAIRYING labor and does very efficient work. The motive power may be either steam or water. Sterilizing. Vessels that have been washed in the man- ner described above may look perfectly clean, but may still be far from being free from bacteria. These can be destroyed only by exposing the vessels to the boiling temperature for some time. Fig. 59.— Cheap Arrangement for Securing Hot Water. The simplest method of sterilizing is to place the vessels in boiling water for five minutes. This method com- mends itself especially to small dairymen who have no steam. Where no steam is available, the best means of pro- curing hot water is the apparatus shown in Fig. 59. The hot water tank is that commonly used in residences for heating water for the bath tub and can be obtained WASHING AND STERILIZING 309 Fig. 60.— Sterilizing Truck and Front of Brick Sterilizer. from plumbers for about $7.00. Any stove in which iron coils can be heated will answer as a heater. The best method of sterilizing is to place the vessels 310 MARKET DAIRYING in a steam chamber of sufficient strength to withstand a pressure of about fifty pounds to the square inch. These sterilizers are usually constructed of concrete or brick and Fig. fit.— Cross-Section of Concrete Sterilizer. are provided with a heavy iron door which is large enough to admit a truck bearing the pails, cans, bottles, etc. Other sterilizers of this type are constructed of galvanized iron. The principal drawback to some of these sterilizers is WASHING AND STERILIZING 311 their high cost, which renders their use by small dairy- men almost prohibitive. Cheap Sterilizers. A cross section through a cheap concrete sterilizer is shown in Fig. 61. It is essentially a rectangular concrete tank with a wooden cover which is lined with zinc. The sides and bottom are five inches thick and are built of concrete, which is made up of one part cement, two parts sand, and two parts coarse gravel. A thin coat, consisting of one part cement and two parts sand, is used as an inside finish. Fig. 62 shows a common galvanized iron sterilizer which answers the purpose for small dairymen. Fig. 62. -A Cheap Sterilizer. CHAPTER XXXVIII. DAIRY HOUSES. Location. In selecting a site for a dairy house, con- venience and sanitation should be given first considera- tion. A well drained spot, free from rubbish and bad odors, and within reasonable distance from the barn should be selected. An abundance of good, pure water must be available. Floor Plans Designed by the Author. Dairymen who sell milk and cream occasionally have a surplus of these products on their hands, which is usually made into butter. Floor plans for dairy houses must therefore provide for small buttermaking outfits in addition to all the necessary apparatus for the handling of milk and cream. The floor plan shown in Fig. 63 is designed to meet the needs of small dairymen. Figs. 64 and 66 illustrate plans which will answer the needs of dairymen having from twenty to fifty cows. The first two plans provide for retail milk ; the last provides for farm buttermaking. There is no question that refrigerating machinery can be employed very advantageously in a great percentage of the larger dairies. See Fig. 68, page 318. Details of Construction. Tlie foundation for the walls may be constructed of stone, brick or concrete. It should rest upon firm, solid ground below the frost line, and the top must be at least one foot above ground. In building the walls, place the studs two feet apart 312 ( Stovc) 313 Extreme length, 16 feet. I Extreme width, 12 feet. Fig. 63.— Floor Plan of Dairy House for Retail Milk. and tack building paper on both sides. Weather board the outside and finish the inside as follows: Board up preferably with tongued and grooved lumber, and cover the boards with two thicknesses of 314 MARKET DAIRYING Fig. 64.— Floor Plan of Dairy House for Retail Milk Trade, Suitable for Fifty Cows. 18'x24\ roofing paper. Next put on furring strips, one foot apart, and to these fasten wire lathing. If the lathing is pro- vided with one-inch steel ribs the furring strips are not DAIRY HO USB 315 needed. Next apply one and one-half inches of cement plaster consisting of one part cement, three parts clean, coarse sand, and one part slacked lime paste. Press the Fig. 65.— Milk House for Cream Patrons. concrete partly through the wire lathing. Finish with one part cement and one part sand and trowel off as smoothly as possible. This construction provides one three-fourths inch and one four-inch dead air spaces. 316 MARKET DAIRYING Fig. 66.— Floor Plan of Dairy House for Farm Buttcrinaking. DAIRY HOUSE 317 Construct a four-inch concrete floor upon a well tamped foundation consisting of gravel, cobble stones and cinders. TEST TABLE (stove) 5X10 WATER TANK p 7X10 MILK COOLER Fig. 67.— Milk House Whole Milk Patrons. These materials afford good drainage and thus prevent the cold and dampness Ltsually associated with concrete floors. In preparing the concrete for the floor use one part 318 MARKET DAIRYING Fig. 68.— Floor Plan of Dairy House Suitable for Forty to Eighty Cows. (Mechanical Refrigeration.) 18'x30'. DAIRY HOUSE 319 cement, two parts clean, coarse sand and four parts gravel or crushed stone. Finish with one part cement and two parts sand. All parts of the floor should slope toward the drain in the center. Round out the corners and edges of the floor with concrete to make them more easily cleanable. The ceiling should be about twelve feet high and built of the best ceiling lumber. Keep the ceiling well painted. Enough windows must be provided to afford ample light and to admit sunshine to all parts of the building. Provide ventilation in the milk and wash rooms by running tight ventilating shafts from the ceiling through the top of the roof. Sewerage. Effective sewerage must be provided at the time the floor is laid. A bell trap should be placed in the center of each room and carefully connected with the sewer. Conduct the sewage far enough away to keep its odors a safe distance from the dairy house. Screening. Where proper sanitation is expected it is absolutely necessary to guard against flies, and this can easily be done by screening all doors and windows. Flies are a prolific source of milk contamination and must therefore be rigidly excluded from the dairy. CHAPTER XXXIX. CITY MILK AND ICE CREAM PLANTS. Perhaps of all dairy buildings, the least uniformity of construction is found in city milk and ice cream plants. This fact was thoroughly impressed upon the author dur- ing a tour of inspection which included visits to some of the best plants in the country. It is to be expected that the same method of construc- tion cannot be followed in all its details under all condi- tions, yet it is believed that there are at least some prin- ciples that may be advantageously embodied in the con- struction of all buildings of this kind. The plans which accompany this article are, therefore, not submitted with the idea of meeting all conditions, but rather to furnish suggestions which it is believed will prove valuable to most prospective builders. City Milk Plants. For sanitary reasons, it is desir- able to eliminate pumps and piping as far as possible. Whatever piping is needed should be in short sections, easily detachable, smooth and well tinned, not galvanized. In the gravity scheme shown in the illustration on page 322, the amount of piping is reduced to a mini- mum. The milk cans are raised to the second floor by means of an elevator. Here the milk is sampled and weighed and takes its course as shown in the vertical section. It will be noted that from the receiving vat the milk passes into- a clarifier which removes any suspended foreign matter from the milk. Many milk plants do not 320 CITY MILK AND ICE CREAM PLANTS 321 use clarifiers, but those who do, claim that the clarific- tion of milk is a paying proposition. So long as milk is not produced under the sanitary conditions which now prevail upon certified dairy farms, just so long will clari- fication remain a desirable practice. The plans submitted provide for pasteurization by the held or retarder process. When the heating is finished the milk is discharged over a large cooler of the tubular style which is most commonly used in milk plants. It will be noted that the plan provides for a room de- voted exclusively for making butter, ice cream, cultured milk, fancy cheese and modified milk, all of which can be profitably undertaken by milk dealers, and sufficient room should be provided to allow for expansion in these side lines. One common mistake in milk plants is the failure to isolate the wash room. This is a very essential matter because milk is certain to become contaminated when the washing is done in the same room in which it is pasteur- ized or bottled. The illustration shows the use of steam only as a source of power. In some of the larger plants, however, the machinery is run with gas power, which is far more economical than steam. It is estimated that a pound of coal burned in a gas producer will develop about eight times as much power as the same amount of coal burned under the boiler. In a large and expensive milk plant recently con- structed the gravity system of handling milk is used dif- ferently from that shown in the foregoing illustration. The different machines are elevated one above the other by a series of platforms arranged between the floor and the ceiling. Necessarily the ceiling is a considerable dis- 322 MARKET DAIRYING tance from the floor. An elevator brings the milk to the receiving vat from which it flows into the clarifier, thence into a standardizing vat, thence into the pasteur- izer, and so on down the line. The space under the plat- forms is used as a wash room. I PLATFORM COLD STORAGE WASH ROOM .MOD/F/ED M/L/f BOTTLE FILLERS SEPARATING BUTTERMAfflNG CULTURED MILK FANCY CHEESE /CE CREAM FIRST FLOOR ICE MAKING TANKS ELE- T0ILLT[ VAWR COMPRESSOR ENGINE COAL BO/LEff BASEMENT COLD STORAGE ELE MM wj^iXP CLARIFIER DDD PASTEURIZERS TESTING ROOM OFFICE GENERAL STORAGE SECOND FLOOR % RECEWNG VAT RAfTEl/R/ZERS*-5: im COOLER MOTTLE FILLER 'COLD STORAGE BASEMENT VERTICAL SECTION-SHOWINS COURSE OF MILK Fig. 69.— Plan for City Milk Plant. In some large plants the milk is weighed in a can sunk in the first floor and from there run into a receiv- ing vat , in the basement. From this point the milk is pumped to the top floor. In still other plants, all the work is done on one floor, the milk being pumped from one machine to another, three, and in some cases four, pumps being kept busy. CITY MILK AND ICE CREAM PLANTS 323 City Ice Cream Plants. In the construction of ice cream plants, the situation is similar to that of milk plants, in that each plant has its own peculiar arrange- ElE WTOR. Wash Room Butter, Making- T Platform Cold (Storage Freezers ooo First Floor. Ice Making- Tan k.c5 az S3 2 uj 8= — = z Coal Boiler. Basement TEcSTING- Tloom Office General (Storage El EVATO^ Platform H Hori OGEN IZ F.RPA3 T EUBIZt R3 DDD Mixing andHoldingVak O'O I I GoOLE.R_» Second Floor, Vehticalc5ection Showing (quiweofCr&m Fig. 70.— Plan for City Ice Cream Plant. ment for handling the cream. Some ice cream manufac- turers follow the one floor plan, others follow the grav- ity system entirely. The one floor plan in ice cream plants is open to the same objection as the one floor plan 324 MARKET DAIRYING in city milk plants, namely, requiring the use of pumps and too much piping. The two floor plan, shown in the accompanying illus- tration, seems to furnish the best conditions for handling the cream. An elevator is used to raise the cream cans to the second floor where the cream is weighed and sampled and then emptied into a receiving vat placed upon an elevated platform. From the receiving vat the cream flows into a "held" process pasteurizer and from this it is discharged into the homogenizer, a machine which is at present used by most large ice cream manu- facturers. The homogenizer forces the cream to the top of the cooler, which should be of ample size to permit reducing the temperature to near freezing. From the cooler the cream passes into the mixing vat in which it is standardized and the necessary ingredients added. From the mixing vat the "mix" flows directly into the freezers. Most ice cream manufacturers prefer to keep the pasteurized cream in the refrigerator several days, and even a week, before freezing so as to give more body to the cream, thus increasing the "swell" in the freezing process. Storing cream in this manner is open to two serious objections: (i) the increased labor and expense of storing; and (2) the deterioration in the flavor of the cream. There is nothing to justify the prolonged storing of pasteurized cream before freezing, except the slightly increased overrun, and the best ice cream manu- facturers have found that the extra cost of labor and cold will offset any advantage in yield. Every hour cream is held in cold storage the flavor suffers and for this reason some of the best ice cream manufacturers freeze their cream the same day it is pasteurized. CITY MILK AND ICE CREAM PLANTS 325 In the foregoing illustration the arrangement does not provide for holding cream in the refrigerator after pas- teurization. Cream, however, could be held over a day in the mixing vat by providing the latter with the neces- sary cooling coils. What has been said in regard to the economy of using gas power in milk plants applies with equal force to ice cream plants. Sanitary Features. Matters of prime importance in the construction of milk and ice cream plants include an abundance of light and the use of material which can easily be kept clean. There is no better disinfectant than sunlight, and too many windows cannot be inserted in buildings used for handling milk and cream. To secure the maximum amount of sunlight some of the best milk plants use dormer windows or skylight. To be sanitary, the floors, walls and ceiling should be constructed of concrete; in fact the entire building should be built of brick or concrete. Where it is desired to combine "showiness" with sanitary efficiency, more expensive material such as tile may be used for inside finish. Reinforced Floors. To increase the wearing quality of concrete floors, perforated steel plates should be em- bedded in the surface of the concrete floor immediately after the cement finish has been applied. CHAPTER XXXX. THE BOILER AND ITS MANAGEMENT. A boiler is indispensible in a well equipped dairy. The steam which it provides is important, not only in securing hot water and in sterilizing, but also in furnishing power. A steam engine will be found useful in most dairies for pumping water, separating milk, churning and freezing cream, and by extending the shaft through one side of the building its usefulness may be extended to sawing wood, washing clothes, running the grindstone, etc. For the smaller dairies the upright form of boiler will be found the most satisfactory. But for dairies having upwards of fifty cows, the horizontal form of fire-tube boiler should be used. The latter style is laid in brick. The grates are supported upon brickwork and heat and smoke pass along the underside of the boiler toward the rear and return through the fire-tubes. To prevent radiation of heat the brick work must be built up to cover the entire boiler. The fire box must be constructed of the best fire brick. The various boiler accessories will be described in the following paragraphs : Glass Gauge. This is a glass tube attached to the side of the boiler to indicate the height of the water in it. It is so attached that its lowest point is about two inches above the highest part of the fire line of the boiler, its entire length being usually about fifteen inches. The 326 BOILER AND MANAGEMENT 327 cock at the bottom is used to blow out the sediment that is liable to block the opening between it and the boiler. When this occurs the gauge becomes a false indicator. Frequent blowing out is therefore necessary. The cock next to the blow-out admits the water from the boiler. The cock above this admits the steam. When the glass breaks shut off the water first, then the steam. Always have a few extra glasses on hand so that the broken one can be immediately replaced. Owing to its tendency to clog, the gauge can not always be relied upon, hence the use of water cocks placed next to the glass gauge. Water Gauge Cocks. There are three of these used. The water level should be kept as near as possible to the middle cock. It should never go below the lower cock, nor above the upper. These cocks should be opened many times during the day, and so long as steam issues from the upper and water from the lower cock, the water level is all right. Steam Gauge. This shows the number of pounds of steam pressure per square inch on the boiler by means of a pointer moving around a dial. Below the dial is a loop which contains water to prevent injury to the gauge from the hot steam. The steam gauge is liable to get out of order and will then fail to show the true pressure. Such a condition is indicated by the safety valve. Safety Valve. This is placed on top of the steam chamber and permits the escape of steam when the steam pressure reaches the danger limit. It is an indispensable boiler attachment as without it the boiler would be a dangerous thing. There are two kinds of safety valves, the "pop" and "ball and lever" types. The former is considered the more desirable because it is not so easily 328 MARKET DAIRYING tampered with. Both can be set to blow off at different pressures. Water Feed Apparatus. There are two ways of feeding water into a boiler, namely, with injectors and with pumps. Injector. This important boiler accessory is attached to the side of the boiler. It utilizes the steam directly from the boiler for forcing water into it against a pressure as great as that which sends it forth. The principle which makes this possible may be stated as follows : Steam issuing from a boiler under 70 pounds pressure has a velocity of 1,700 feet per second. When steam with this high velocity strikes the combining tube it produces suction which in turn induces a flow of water. As soon as the water enters the combining tube it is given motion by the high velocity of the steam, which immediately condenses and moves with the water into the boiler at a comparatively low velocity. The energy, therefore, by which steam can force water into the boiler against its own pressure is the latent heat resulting from the condensation of the steam in the combining tube. From this it must be evident that the efficiency of the injector is dependent upon the completeness with which the steam condenses. This is clearly proven by every day practical experience. When, for instance, the feed water is too hot, the steam pressure too high, or the steam is wet, the injector fails to work properly because the steam does not sufficiently condense when it strikes the feed water. Starting the Injector.- This is clone by opening the supply water valve one or two turns, then the steam valve wide. If steam issues from the overflow admit a little more water ; if water overflows admit less. BOILER AND MANAGEMENT 329 Care of Injector. An injector will become coated with sediment or scale the same as the boiler and must, therefore, be frequently cleaned. This is best done by immersing it in a solution of one part muriatic acid and ten parts water. Allow to remain in this solution until the scale becomes soft enough to permit washing out. A clean injector rarely causes trouble but if trouble does occur it may be due to : (i) low steam pressure; (2) too hot water; (3) leaks in pipes and injector; (4) clogging of water pipe; (5) wet steam; (6) poor working condi- tion of check and overflow valves; (7) clogging of feed pipe where it enters the boiler. The injector is commonly used to feed water into the boiler because it is cheap and simple, and occupies little space. Pumps. There are two kinds ; ( 1 ) those run with steam directly, and (2) those run by the engine. The latter is the more economical and handles hot water with less trouble. It has one disadvantage, however, and that is it does not work unless the engine is running. With good pumps, especially those run by the engine, good work may be expected when the feed water has been heat- ed to 200 F. with the exhaust steam from the engine. With the injector such high temperatures are not per- missible, hence the greater economy of the pump. The great saving of fuel by feeding water hot into the boiler is illustrated by experiments made by Jacobus which show that with a direct acting pump 12.1% fuel is saved by heating the feed water from 6o° to 200 before pump- ing it into the boiler. With injectors the feed water used usually has a temperature of about 6o° F. Steam. Water is practically a non-conductor of heat. This means that it cannot conduct its heat to its neighbor- 330 MARKET DAIRYING ing particles. When, therefore, heat is applied to the bot- tom of a vessel containing water, the particles at the bottom do not communicate their heat to the particles next above them, but expand and rise, cool ones taking their places. This gives rise to convection currents which tend to equalize the temperature of the water in the vessel. When the water has reached a uniform temperature of 212° F. the particles begin to fly of! at the surface in the form of vapor, and this we call steam. To generate steam in a boiler, then, it is necessary to impart to the water in it a considerable amount of heat, which is produced by burning fuel in the fire box. FIRING OF BOILER. The immense amount of heat stored in wood and coal is rendered effective in the boiler by burning (combus- tion). To understand how to fire a boiler intelligently one must first learn what the process of burning consists of.. Process of Burning. Anything will burn when the temperature has been raised high enough to cause the oxygen of the air to unite with it. Thus, in "striking" a match the temperature is raised high enough by the friction produced to cause the match to burn. The burn- ing match will produce heat enough to ignite the kind- ling, which in turn, produces the necessary heat to ignite the wood or coal in the fire box of the boiler. Burning may, therefore, be defined as the union of the oxygen of the air with the fuel. In burning a pound of coal or wood a definite amount of air must be admitted to furnish the necessary oxygen for complete combustion. When oxygen is lacking part of the fuel passes out of the chimney un- BOILER AND MANAGEMENT 331 burned in the form of gases. If, on the other hand, too much air is admitted the excess simply passes through the chimney, absorbing heat as it passes through the boiler. The problem of firing becomes, therefore, a diffi- cult one. Burning Coal and Wood. When hard coal is burned the fire should be thin. A thickness of three to four inches on the grates gives very satisfactory results. For best results with soft coal a thickness of six to seven inches is recommended. Whenever fresh coal is added it should be placed near the front and the hot coals pushed back. In case wood is burned the fire box should be kept well filled, care being necessary to keep every part of the grates well covered. GENERAL POINTERS ON FIRING. i. 'Boilers newly set should not be fired within two or three weeks after setting and then the firing should be very gradual for several days to allow the masonry to harden without cracking. 2. Never fire a boiler before determining the water level by trying the water gauge cocks. You can not entirely rely upon glass gauges, floats, and water alarms. 3. When starting the fire, open the upper water gauge cock and do not close it until steam begins to issue from it. This permits the escape of confined air. 4. Kindle the fire on a thin layer of coal to protect the grate bars. 5. Always examine the safety valve before starting a fire. 6. When starting the fire all drafts should be open. 332 MARKET DAIRYING 7. The firing should be gradual until all parts of the boiler have been heated. 8. Never allow any part of the grate bars to become uncovered during firing. 9. Frequently clean the ash pit to prevent overheating of grates from the hot cinders underneath. 10. The coals upon the grates should not be larger than a man's fist. n. Remember that firing up a boiler rapidly is apt to cause leaks. 12. Remember that too little water in the boiler causes leaks and explosions. 13. Remember that soot and ashes on heating surfaces always waste fuel. 14. When fire is drawn, close dampers and doors of furnace and ash pit. 15. ■ Never open or close valves when the water is too low in the boiler, but immediately bank the fire with ashes or earth. Opening the safety valve at such a time will throw the water from the heated surfaces, resulting in overheating and possibly in explosions. 16. Use the poker as little as possible in firing. 17. Keep the grate bars free from "clinkers." 18. When the steam pressure goes too high, start the pump, open the doors of the furnace and close the ash pit. 19. A steady and even fire saves fuel. GENERAL CARE OE BOIEER. i. Always close the steam and water valves of the glass gauge when you leave the building for half an hour or more. BOILER AND MANAGEMENT 333 2. Water gauges should frequenty be blown out and cleaned. 3. Keep the exterior of the boiler dry. Moisture will corrode and weaken it. 4. The boiler should be blown off under low pressure every two or three days. 5. A boiler that is not used for some time should be emptied and dried. If this cannot readily be done, fill it full of water to which a little soda has been added. 6. Frequently examine the safety valve to see that it is in good working order. 7. Do not empty boiler while brick work is very hot. 8. Never pump cold water into a hot boiler. Leaks and explosions may be the result. 9. Leaky gauges, cocks, valves, and flues should be repaired at once. 10. Do not fail to examine the pressure gauge fre- quently. 11. It is good policy to have two means of feeding a boiler. The pump or injector may get out of order and cause delay and danger. 12. Feed pumps and injectors need frequent cleaning to keep them in good working order. 13. Look out for air leaks. If air is admitted any- where except through the grates serious waste may re- sult. Such leaks are to be looked for in broken doors and poor brick work. 14. Flues should be cleaned often, especially if soft coal is burned. This will prevent overheating of metal and at the same time save fuel. 15. Do not allow filth to accumulate around the boiler or boiler room. 16. Keep all the bright work about the boiler "shiny." 334 MARKET DAIRYING iy. Do not 'fail to empty the boiler every week or two and refill with fresh water. 1 8. Have your steam gauge tested at least twice a year. BOILER INCRUSTATION* In all boilers after a period of use, there is deposited upon the parts below the water level a scale or sediment known as boiler incrustation. Cause of Scale. The formation of scale is due to the impurities contained in the feed water. When impure water is fed into the boiler the impurity first manifests itself in the form of scum on top of the boiling water. The heavier particles of the scum slowly unite and sink to the bottom where they first appear as mud. By con- tinued exposure to high temperature, this mud gradually forms into a hard impervious scale which usually con- sists largely of lime. Objection to Scale. I. The excessive formation of boiler scale is the immediate cause of most boiler explo- sions. The scale acts as a non-conductor of heat, so that in cases where the capacity of the boiler is severely taxed, the metal becomes overheated, thus materially weakening it. The scale is, therefore, not only dangerous, but by overheating the metal, also materially shortens the life of the boiler. 2. Another most serious objection to scale is its wastefulness of fuel. This becomes evident when we note that the heat before reaching the water must first be conducted through a non-conducting layer of incrusta- tion. Prevention of Scale. Since nearly all water used for boilers is more or less impure, it is evident that to prevent scale, boilers must receive frequent cleaning. How often BOILER AND MANAGEMENT 335 this needs to be done is, of course, dependent upon the amount and character of the impurity in the water. Boilers are kept clean in three different ways, (1) by blowing off at low pressure, (2) by cleaning through manhole, and (3) by using boiler compounds. (1). By blowing the boiler off at low pressure most of the mud will be blown out. But care must be taken that the pressure is not above ten pounds and that there is no more fire in the fire box, otherwise the mud, instead of flowing out with the water, will bake on and form scale. (2). A good way of removing mud is to 'allow the boiler to cool off and then run a rubber hose through the manhole. By working the hose and forcing water through it the sediment can be removed. (3) Boiler compounds are used to keep boilers free from scale. The kind of compound to be used is deter- mined by the character of the impurities of the water. Most dairies use well water for the boiler and the chief impurity in this is lime. The best compound for water of this kind is soda. Well water contains the lime in widely different proportions. In order, therefore, to as- certain the proportion of soda to feed water the following method is recommended by Hawkins: "1. Add one sixteenth part of an ounce of soda to a gallon of the feed water and boil it. 2. When the sedi- ment thrown down by the boiling has settled to the bottom of the kettle, pour the clear water off and add one-half drachm of soda to this. Now, if the water remains clear, the soda which was put in has removed the lime. But if it becomes muddy, the second addition of soda is neces- sary." In this way the amount of soda to be added to the feed water can be calculated with sufficient accuracy. 336 MARKET DAIRYING Tan bark is very efficient in removing boiler scale but may injure the iron. Kerosene answers the same purpose but renders the steam unfit for use in the dairy. When the water is salt or acid, a piece of metallic zinc occasionally placed in the boiler will prevent corrosion. Water of this kind can usually be told by its corrosive effect on copper and brass. Acid water can also be de- tected with blue litmus paper, which it turns red. WET AND DRY STEAM. Wet Steam.. This is steam holding in suspension ex- tremely small particles of water which are thrown off* from the water surface while steam is generating. The following are the causes of wet steam: i. Impure water in the boiler. 2. Too much water in the boiler. 3. Too little evaporating surface for the amount of steam used. This is one of the chief objections to upright and too small boilers. 4. Violent agitation of the water in the boiler caused by too rapid a generation of steam. Wet steam causes "priming" and is wasteful of heat. Dry Steam. This is saturated steam holding no water mechanically in suspension. High steam pressure and a large steam space above the water level are conducive to dry steam. CHAPTER XXXXI. WATER AND ICE SUPPLY. WATER SUPPLY Importance of Pure Water. A great deal of disease in farm homes is directly traceable to infected water. Typhoid fever especially is so frequently caused by pol- luted well water that physicians at once look to this as the probable cause wherever this disease is found to ex- ist. Where wells infected with disease germs happen to ex- ist on dairy farms that supply milk to neighboring cities, disease is not limited to the dairyman's own family, but may be spread along the entire milk route. Many typhoid fever epidemics have been positively traced to milk which has become infected through water containing the disease germs. Nowhere is pure water so important, therefore, as upon dairy farms. The disease germs usually find their way into the milk through milk vessels which have been washed with in- fected water. The use of such water for washing cows' udders previous to milking may also be the means of in- fecting the milk supply. Location of Well. The most satisfactory location for the well is at the dairy house where the coldest water is required and where it will be most convenient. Here the water for both the dairy, the home, and the stock can be pumped with the dairy engine. Further, the well, like 337 338 MARKET DAIRYING the dairy house, should stand on slightly elevated ground so as to insure drainage away from it. Construction of Well. In a properly constructed well, no water should enter it except near the bottom. This compels the water to pass through a thickness of earth sufficient to purify it where the wells are of a reasonable depth. Where there is no rock or hard clay and where the Ordinary Weft. Fig. 71.— Soil Strata. (From Harrington's "Practical Hygiene.") water can be had at a reasonable depth, the driven well, commonly knov/n as the Abyssinian tube well, is the cheapest and one of the safest. This well is made by driving into the ground a water-tight iron tube, the lower end of which is pointed and perforated. In case rocks and hard clay must be penetrated, or great depth must be reached to secure water, the bored or drilled well, piped from top to bottom with water-tight iron pipes, will be found most satisfactory. WATER AND ICE SUPPLY 339 Water from the upper pervious stratum should be avoided wherever possible, even with wells of the kind just described. Especially is this necessary where the wells are shallow. The purest water is obtained by sink- ing the well" through an impervious stratum, like that shown in Fig. 71. The most dangerous well is the common dug well with pervious walls and so located as to permit seepage into it from outhouses, barnyards and cesspools. Wells of this type are altogether too common on dairy farms. Fig. 72. -Sources of Well Water Contamination. (From Bui. 143 Kan. Exp. Sta.) All wells, whatever their construction, must be provided with water-tight metallic or concrete covers to prevent the entrance of impurities into the shaft. ice SUPPLY. Necessity of Ice. Where there is no equipment for 340 MARKET DAIRYING mechanical refrigeration, ice is indispensible in furnish- ing the best quality of milk and cream. A low enough temperature cannot be secured with water alone, neither can the cooling be accomplished as quickly as is desirable for best results. Furthermore, a satisfactory cold storage cannot be had without the use of ice. Cooling Power of Ice. A great deal of cooling can be done with a comparatively small amount of ice. This is due to the latent or "hidden" cold in ice. Thus to convert one pound of ice at 32 ° F. into water at the same temperature requires 142 units of heat, or, in other words, enough cold is given out to reduce the temperature of 142 pounds of water one degree Fahr. Construction of Ice House. To keep ice satisfactorily three things are necessary, ( 1 ) good drainage at the bot- tom, (2) good insulation, and (3) abundant ventilation at the top. Good drainage and insulation at the bottom can be se- sured by laying an eight-inch foundation of stones and gravel and on top of this six inches of cinders, the whole being underlaid with drain tile. One foot of sawdust should be packed upon the cinders and the ice laid directly upon the sawdust. Satisfactory walls are secured by using matched boards on the outside of the studs and common rough boards on the inside, leaving the space between the studs empty. The ice should be separated from the walls by one foot of sawdust. Where no solid foundation walls are provided, earth must be banked around the ice house to prevent the en- trance of air along the base. The space between the sawdust covering on top of the ice and the roof should be left clear. Openings in the WATER AND ICE SUPPLY 341 gable ends as well as one or two ventilating shafts pro- jecting through the roof should be provided to insure a free circulation of air under the roof. This will not only remove the hot air which naturally gathers beneath the roof, but will aid in drying the sawdust. The ice must be packed solidly, using no sawdust except at the sides and bottom of the ice house and on top of the ice when the filling is completed. At least one foot of sawdust must be packed on top of the ice. Size of Ice House. The size of the ice house will depend, of course, upon the amount of ice to be used. For a herd of 25 cows, in the North, an ice house 10 feet square by 14 feet high will usually answer. These dimensions provide storage for 22 tons of ice, allowing one-foot space all around the ice for sawdust. In the South about 50% more ice is required than in the North. In calculating the amount of storage space needed for ice, it is necessary to know that one cubic foot of ice at 32 F. weighs 57.5 pounds. As a matter of convenience in filling and emptying the ice house, doors should be provided in sections from the sill to the gable at one end of the building. General Uses of Ice. Aside from the use of ice in cooling milk and cream, it can be employed to good ad- vantage in several other ways. Its value in the house- hold, in preserving meats, vegetables, and fruits cannot be overestimated. And what is so refreshing as cold drinks and frozen desserts during the summer months ! Ice is also frequently necessary in case of sickness. Cost of Making Ice. Where ice can be obtained with- in a reasonable distance, the cost of cutting, hauling, and packing should not exceed $1.50 per ton. Source of Ice. Always select the cleanest ice available. 342 MARKET DAIRYING Where the source of ice is at too great a distance from the dairy, an artificial pond should be made upon ground with a reasonably impervious subsoil and with a natural concave formation. If such a piece of ground is flooded with water during the coldest weather, an ample supply of ice will be available in a very short time. Insulated Ice Houses. The present tendency is to use ice houses with insulation sufficient to dispense with the use of sawdust. With ice houses of this kind, the refrigerator is cooled by circulating the air directly over the ice in the ice house. See Fig. 37>^, page IOI. CHAPTER XXXXII. sewage; disposal from dairy and dwelling. To secure a high degree of sanitation in and about the dairy house it is necessary to see that proper disposal is made of the sewage from both the dairy and the dwelling. Where the latter is situated close to the dairy house its surroundings may do fully as much harm as those of the dairy itself. With open privies and the careless dumping of kitchen slops near the dwelling, we have a double means of en- dangering the dairy. If the ground near the dwelling and privy slopes in the direction of the water supply, the latter is likely to become contaminated through seepage in the manner indicated in Fig. 63. In addition to this -there is the danger of flies carrying various kinds of bacteria from these places to the dairy house. Flies not only carry the obnoxious, putrefactive species, but too often also the deadly pathogenic kinds, such as cause typhoid fever, to say nothing of the off ensive . excrementitious matter conveyed in this manner. Obviously the accumulation of sewage about the dairy house is attended by practically the same danger as that arising from the unsanitary surroundings of the dwelling. Moreover there is certain to be trouble also from bad odors. SEPTIC TANK. The best means of taking care of the sewage from 343 344 MARKET DAIRYING both the dairy and the dwelling is to run it into a septic tank (see Fig. 73, designed by the author) and from this into a net-work of tile laid underground where it will irrigate and fertilize the soil. Object of Septic Tank. The main purpose of the tank, as its name indicates, is to thoroughly decompose all organic matter entering it. This is accomplished by numerous species of bacteria, and the tank may be properly designated as a germ incubator. Where the Fig. 73 —Septic Tank. sewage is emptied into underground tile, the tank also serves as a storage, discharging its contents intermittently. This is necessary to force the liquid to all points of the system and to allow time for each discharge to soak away before the appearance of the next. Construction of Tank. The general plan of construc- tion is illustrated in Figs. 73 and 74. The tank is located in the ground with the top within a foot or two of the surface. For durability it is preferably constructed of brick, stone or concrete. The tank is so constructed as to SEWAGE DISPOSAL 345 I r ' V. ;' "" •E I / B cm * HAfGt retain all sediment and floating material, since the dis- charges permit the withdrawal of the liquid from near the middle of the tank only. This is one of the main features of the tank. All inorganic matter entering the tank will gradually settle and, of course, remain in it. Some of the organic matter tends to settle during the first 24 hours, after which it comes to the surface to be gradually wasted away by the action of bacteria. This wasting away is naturally very slow, and since the slowly gathering organic matter nearly all remains in the first section of the tank, this must be large enough to provide for a consider- able accumulation of it. The tank should be built air tight, except in two places. At the right is an air inlet, consisting of a goose-neck- pipe, which renders the vent at the top more effective. This vent consists of a long shaft extending beyond the top of the dairy, thus carrying off the foul gases caused by the decomposition of the material within. One-inch gas pipe, properly fastened, will serve as a satisfactory vent. In order to afford communication of sections A and C with the vent, the two partitions should not be built quite as high as the tank. There should be at least one inch space between the top of the partitions and the cover. A 1 y 2 -inch gas pipe should be laid over the tank through which the water from the cooler and vats may be discharged directly into the drain. This water Fig. 74.— Cross Section of Septic Tank. 346 MARKET DAIRYING requires no purification and, if conducted through the tank, would necessitate one of too large dimensions. Moreover, the large amount of cold water needed for cooling milk and cream would cool the contents of the tank too much for a rapid decomposition of the material within. Size of Tank. This must necessarily depend upon the amount of sewage run into it. In general it should have capacity sufficient to hold all of one day's waste in the smallest section (C). It will be noticed from the cut that section A is considerably larger than either of the other two. The reason for this is that nearly all of the inorganic matter remains in the bottom of this part of the tank, while the organic matter, as already stated, gradu- ally accumulates at the surface in this section, in spite of constant decomposition. Where the tank receives the sewage from both the dairy and the dwelling, a tank 12 feet square by 4^2 feet deep will be large enough, provided the water used for cooling is not run into it. It is well to remember, however, that the larger the tank used the better the results that may be expected from it. Flow of Sewage Through Tank. Four-inch tile, carefully laid, may be used to conduct the sewage from the dairy to the tank. A trap is placed near the dairy to shut off the odors coming from the drain. At the point at which the sewage enters the tank it is desirable to attach an elbow with an arm sufficiently long to keep the lower end always in the sewage. This prevents un- due mixing of the incoming sewage with that already in the tank, a matter of importance in the successful operation of the tank. When the sewage in section A has reached the dotted line, it begins to discharge into section B through three- SEWAGE DISPOSAL 347 inch .gas pipe as shown in Fig. 73. The liquid is with- drawn from a point near the middle of the tank as in- dicated by the discharge pipes. The eight-inch space above the discharge permits the accumulation of organic matter. The discharge from 'B into C, is the same as that from A into B ; but the discharge pipes are of neces- sity lower by an amount indicated by the dotted lines. Compartment C discharges intermittently by means of an automatic syphon. The sewage becomes gradually purified in its passage through the tank, and as it flows from the last section it is nearly as clear as water, but has a slightly sour odor, which it seems to retain and which is in no way objection- able. The purified sewage has been kept for weeks with no sign of the development of putrefactive odors. The discharges should be arranged as shown in Fig. 65. This arrangement will cause the least mixing of old and new sewage. There is no discharge from A into B until the second day's sewage flows into A. Similarly there is no discharge from B into C until the second discharge into B, etc. The sewage, therefore, requires from three to four days in its passage through the tank. Cost of Septic Tank. A double partition tank, 12 feet square and 4^2 feet deep, constructed of concrete consisting of one part cement, two parts sand and four parts gravel, will cost approximately $50.00 when the walls are five inches thick. SEWAGE DISPOSAL FROM DWELLING. The open privy and the cesspool of kitchen slops are objectionable not only in so far as they affect the dairy house, but also in that they constitute a source of danger to the members of the family in ways entirely discon- nected with the milk supply. With the dairy house 348 MARKET DAIRYING already equipped with power to pump and elevate water, there is apparently no reason why the dwelling should not be equipped with a water closet. And with a water closet in the house there would be practically no expense connected with the disposal of the kitchen waste, since this would be discharged directly into the soil pipe con- nected with the closet. What a convenience such an equipment would afford to the housewife and members of the family ! If the dwelling and dairy house are reasonably close together, one septic tank will answer for both. In such a case the tank is located between the two buildings. Where a great distance separates the buildings, a tank is provided for each and the outlets are brought together as near the tank as possible to save extra expense of tile. SUBSURFACE IRRIGATION. While the septic tank sufficiently decomposes the organic matter to leave the sewage from the tank without offensive odors, it is best to run the discharge into a system of underground tile where it will serve as a fer- tilizer and as an irrigating agent. The tile should be laid below the frost line. In loose soils one foot of tile per gallon of sewage will answer. Clayey soils require two to three times this amount. Three-inch agricultural drain tile are best adapted for drainage work of this kind, the tile being" laid with open joints and with a slope of three or four inches per hundred feet. It is important that this subsurface irrigating system be located where there is no seepage into the water supply. In places where there is no danger from frost it is best to lay the tile only about one and one-half feet below the surface. APPENDIX. Composition of Butter. According to analyses re- ported by various experiment stations, American butter has the following average composition : Per cent. Water 13 Fat 83 Proteids 1 Salt 3 Composition of Cream. Cream contains all the con- stituents found in milk, though not in the same proportion. The fat may vary from 8% to 68%. As the cream grows richer in fat it becomes poorer in solids not fat. This is illustrated in the following figures by Richmond: Total solids. Solids not fat. Fat. Per cent. Per cent. Per cent. 32.50 6.83 25.67 37.59 6.14 31.45 50.92 5.02 45.90 55.05 4.65 50.40 57.99 4.17 53.82 68.18 3.30 64.88 The same authority also reports the following detailed analysis of a thick cream : 349 350 MARKET DAIRYING Per cent. Water 39-37 Fat .... Sugar . Proteids Ash ... Composition of Buttermilk. According to Vieth, buttermilk from ripened cream has the following compo- sition : Per cent. Water 90-39 Fat Milk sugar 4 Lactic acid Proteids . 3 Ash Creamery buttermilk should not average above .2% fat. Composition of Skim=milk. Richmond has found the following average composition of separator skim- milk: Per cent. Water 90.50 Fat Milk? sugar 4 Casein 3 Albumen Ash COMPARISON OF CENTIGRADE AND FAHRENHEIT THER- MOMETER SCALES. Thermometer. F. c. 212 32 100 Difference between boiling and freezing point 180 100 APPENDIX 351 From the above it will be seen that one degree Centi- grade is equivalent to 9-5 degrees Fahrenheit. Hence the following rules: 1. To change C. into F. reading, multiply by 9-5 and add 32. Example: 50°C = (50 X f) + 32 = 112°F. 2. To change F. into C. reading, subtract 32 and multiply by 5-9. Example: 182°F == (182 — 32) X f =83£°C. METRIC SYSTEM OE WEIGHTS AND MEASURES. This system was devised by the French people and has very extensive application wherever accuracy in weights and measures is desired. Some of its equivalents in ordinary weights and measures are given in the follow- ing table : Ordinary weights and measures. Equivalents in metric system. 28.35 grams. 0.9464 liter. 3.7854 liters. 29.57 cubic centimeters (c.c.) 0.4536 kilogram. 1 inch 0.3048 meter. 352 MARKET DAIRYING DETAILED SCORE CARD FOR JUDGING FARM DAIRIES Owner or lessee of farm P. O. address State Total number of cows Number milking. Gallons of milk produced daily Product is retailed by producer in . Sold at wholesale to For milk supply of Permit No Date of inspection REMARKS , 191. EQUIPMENT COWS. Health Apparently in good health 1 If tested with tuberculin once a year and no tuber- culosis is found, or if tested once in six months and all reacting animals removed 5 (If tested only once a year and reacting animals found and removed, 2.) Comfort Bedding 1 Temperature of stable 1 Food (clean and wholesome) Water Clean and fresh 1 Convenient and abundant 1 STABLES. Location of stable Well drained 1 Free from contaminating surroundings 1 Construction of stable Tight, sound floor and proper gutter 2 Smooth, tight walls and ceiling 1 Proper stall, tie and manger 1 Light, Four sq. ft. of glass per cow (Three sq. ft., 3 ; 2 sq. ft., 2 ; 1 sq. ft., 1. Deduct for un- " even distribution.) Ventilation: Automatic system Adjustable windows 1 Cubic feet of space for cow; 500 to 1000 feet (Less than 500 ft., 2 ; less than 400 ft., 1 ; less than 300 ft., 0; over 1000 ft., 0.) UTENSILS. Construction and condition of utensils Water for cleaning (Clean, convenient and abundant.) Small-top milking pail Facilities for hot water or steam (Should be in milk house, not in kitchen.) Milk cooler Clean milking suits . . ,. MILK ROOM. Location of milk room Free from contaminating surroundings 1 Convenient 1 Construction of milk room Floor, walls and ceiling 1 Light, ventilation, screens 1 Total SCORE Perfect Allowed APPEXDIX 353 SCORE CARD -Continued. METHODS COWS. Cleanliness of cows. STABLES. Cleanliness of stables Floor 2 Walls 1 Ceiling and ledges 1 Mangers and partitions 1 Windows 1 Stable at milking tune Barnyard clean and well drained Removal of manure daily to field or proper pit (To 50 ft. from stable, 1.) MILK ROOM. Cleanliness of milk room UTENSILS AND MILKING. Care and cleanliness of utensils Thoroughly washed and sterilized in live steam for 30 minutes 5 (Thoroughly washed and placed over steam jet, 4 ; thoroughly washed and scalded with boiling water, 3 , thoroughly washed, not scalded, 2.) Inverted in pure air 3 Cleanliness of milking Clean , dry hands 3 Udders washed and dried 6 (Udders cleaned with moist cloth, 4; cleaned with dry cloth at least 15 minutes before milking, i.) HANDLING THE MILK. Cleanliness of attendants Milk removed immediately from stable Prompt cooling (cooled immediately after milking each cow Efficient cooling ; below 50° F (51° to 55°, 4; 56° to 60°, 2.) Storage below 50°F (51° to 55°, 2; 56° to 60°, 1 ) Transportation ; iced in summer (For jacket or wet blanket, allow 2; dry blanket or covered wagon, 1.) Total SCORE Perfect Allowed 60 Equipment + Methods. FINAL SCORE;. NOTE 1.— If any filthy condition is found, particularly dirty utensils, the total *core shall be limited to 49. NOTE 2.— If the water is exposed to dangerous contamination or there is evidence of the presence of a dangerous disease in animals or attendants, the score shall be 0. 354 MARKET DAIRYING SCORE CARD FOR SANITARY INSPECTION OF CITY MILK PLANTS Owner or manager Trade name City Street and No State. Milk Cream Permit or License No Date of inspection No. of wagons Gallons sold daily , 191. EQUIPMENT SCORE Perfect Allowed Building: Location: Free from contaminating surroundings Arrangement Separate receiving room 1 Separate handling room 2 Separate wash room 1 Separate sales room 1 Separate boiler room -. 1 Construction Floors tight, sound, cleanable 1 Walls tight, smooth, cleanable 1 Ceilings smooth, tight, cleanable 1 Provision for light 1 Provision for pure air 1 Screens 2 Minimum of shafting, pulleys, hangers, exposed pipes, etc 1 Apparatus Boiler 2 Hot-water heater 1 Milk cooler 2 Refrigerator 2 Appliances for cleansing utensils and bottles 2 Racks, etc., for utensils and bottles after cleaning 1 Sterilizer for utensils and bottles 2 Bottling and capping machine 1 Wash bowl, soap, and towel for attendants 2 Protection during delivery 2 Condition of apparatus (make deduction for inac- cessible parts, open seams, rusty ware, decayed or battered tables or sink, milk-carrying pipes with rough interiors and lack of frequent hand couplings, and for badly worn and poorly repaired material) . . .4 Laboratory and equipment Water supply Clean , fresh 1 Convenient and abundant 1 Total 20 APPENDIX SCORE CARD -Continued. 355 METHODS Building. Cleanliness : Floors 3 Walls 1 Ceilings 2 Doors and windows 1 Shafting, pulleys, hangers, pipes 1 Freedom from odors 2 Freedom from flies and other insects 3 Drainage 2 Apparatus Cleanliness : Thoroughly washed and rinsed 6 Sterilized in live steam, thirty minutes 5 (Thoroughly scalded after washing with water over 20U° F. or live steam, 3.) Bottle caps sterilized 3 Protected from dirt 2 Handling milk Received below 50° F 5 (50° to 55°, 4; 55° to 60°, 3.) Rapidity of handling in plant 3 Freedom from undue exposure to air in the plant 2 Capping bottles by machine 1 Bottle top and cap protected by covering 2 Storage 45° F. or below 3 (45° to 50°, 2; 50° to 55°, 1.) Inspection Bacteriological work 4 Inspection of dairies supplying milk 5 (Once a year, 1 ; twice a year, 2 ; three times a year, 3 ; four times a year, 4.) Miscellaneous Cleanliness of attendants 2 (General appearance, hands, etc. clothing, 1.) Cleanliness of delivery outfit 1 ; clean washable Total. SCORE Perfect Allowed 15 Score for equipment + score for methods = TOTAL SCORE. NOTE. — If the conditions in any particular are so exceptionally bad as to be inadequately expressed by a score of "0" the inspector can make a deduc- tion from the total score. Inspector. RULES AND REGULATIONS RELATING TO THE SALE OF MILK IN NEW YORK CITY. GRADE A.— FOR INFANTS AND CHILDREN. GUARANTEED MILK. Definition. Guaranteed milk is milk produced at farms holding permits therefor from the board of health, and produced and handled in accordance with the follow- ing minimum requirements, rules, and regulations : i. Only such cows shall be admitted to the herd as have not re-acted to a diagnostic injection of tuberculin. 2. All cows shall be annually tested with tuberculin, and all re-acting animals shall be excluded from the herd. 3. No milk from re-acting animals shall be shipped to the city of New York for any purpose whatever. 4. The milk shall not contain more than 30,000 bac- teria per c. c. when delivered to the consumer, or at any time prior to such delivery. 5. The milk shall be delivered to the consumer only in sealed bottles which have been sealed at the dairy, and shall be labeled with the day of the week upon which the earliest milking, of which the contents of the bottle form part, has been drawn. 6. The milk shall be delivered to the consumer within 36 hours of the time at which it was drawn. 356 APPENDIX 357 CERTIFIED MILK. Definition. Certified milk is milk certified by a milk commission appointed by the Medical Society of the County of New York, or the Medical Society of the County of Kings, as being produced under the super- vision and in conformity with the requirements of that commission as laid down for certified milk, and sold un- der a permit therefor issued by the board of health. No milk shall be held, kept, offered for sale, or sold and delivered as certified milk in the city of New York, which is produced under requirements less than those for guaranteed milk. INSPECTED MILK — RAW. Definition. Inspected milk (raw) is milk produced at farms holding permits therefor from the board of health, and produced and handled in accordance with the follow- ing minimum requirements, rules and regulations : 1. Only such cows shall be admitted to the herd as have not re-acted to a diagnostic injection of tuberculin. 2. All cows shall be tested annually with tuberculin, and all re-acting animals shall be excluded from the herd. 3. No milk from re-acting animals shall be shipped to the city of New York for any purpose whatsoever. 4. The farms at which the milk is produced must ob- tain at least 75 points in an official score of the depart- ment of health. These 75 points shall be made up as follows : A minimum of 25 points for equipment, and 50 points for method. 5. The milk shall not contain more than an average 358 MARKET DAIRYING of 60,000 bacteria per c. c. when delivered to the con- sumer, or at any time prior thereto. 6. Unless otherwise specified in the permit, the milk shall be delivered to the consumer only in bottles. SELECTED MILK — PASTEURIZED. Definition. Selected milk (pasteurized) is milk handled and sold by dealers holding permits therefor from the board of health, and produced and handled in accordance with the following requirements, rules and regulations : 1. The farms at which the milk is produced must ob- tain at least 60 points in an official score of the depart- ment of health. Of these 60 points, a minimum of 20 points shall be required for equipment and a minimum of 40 points for method. 2. All milk of this grade shall be pasteurized, and said pasteurization shall be carried on under a special per- mit issued therefor by the board of health, in addition to the permit for "Selected Milk (Pasteurized.)" 3. The milk shall not contain more than an average of 50,000 bacteria per c. c. when delivered to the con- sumer, or at any time after pasteurization and prior to such delivery. 4. Unless otherwise specified in the permit, the milk shall be delivered to the consumer only in bottles. 5. All containers in which pasteurized milk is de- livered to the consumer shall be plainly labeled "Pasteur- ized." Labels must also bear the date and hour when pasteurization was completed, the place where pasteur- ization was performed, and the name of the person, firm, or corporation performing the pasteurization. APPENDIX 359 . 6. The milk must be delivered to the consumers within 30 hours after the completion of the process of pasteurization. 7. No milk shall be pasteurized more than once 8. No milk supply averaging more than 200,000 bac- teria per c. c. shall be pasteurized for sale under the designation Selected Milk — Pasteurized. General Regulations for Grade A. 1. The caps of all bottles containing milk of Grade A shall be white, and shall contain the words "Grade A" in black letters, in large type. 2. If cans are used for the delivery of milk of Grade A, the said cans shall have affixed to them white tags with the words "Grade A" printed thereon in black let- ters, in large type, together with the designation "In- spected Milk (Raw)" or "Selected Milk (Pasteurized)," as the quality of the contents may require. ■ GRADE B.— FOR ADULTS. SELECTED MILK RAW. Definition. . Selected milk (raw) is milk handled and sold by dealers holding permits therefor from the board of health, and produced and handled in accordance with the following minimum requirements, rules and regu- lations : 1. Only such cows shall be admitted to the herd as have been physically examined by a regularly qualified veterinarian and declared by him to be healthy, and free from tuberculosis in so far as a physical examination may 360 MARKET DAIRYING determine that fact. Such an examination of all cows shall be made at least once each year. 2. The farms at which the milk is produced must ob- tain at least 68 points in an official score of the depart- ment of health. These 68 points shall be made up as follows : A minimum of 25 points for equipment, and a minimum of 43 points for method. 3. The milk shall not contain an excessive number of bacteria when delivered to the consumer, or at any time prior thereto. PASTEURIZED MILK. Definition. Pasteurized milk (Grade B) is milk pro- duced under a permit issued therefor by the board of health, and produced and handled in accordance with the following minimum requirements, rules and regulations and in further accordance with the special rules and reg- ulations relating to the oasteurization of milk : 1. All containers in which pasteurized milk is de- livered to the consumer shall be plainly labeled "Pasteur- ized." Labels must also bear the date and hour when the pasteurization was completed, the place where pasteur- ization was performed, and the name of the person, firm, or corporation performing the pasteurization. 2. The milk must be delivered to the consumer within 36 hours after the completion of the process of pasteur- ization. 3. No milk shall be pasteurized more than once. 4. No milk containing an excessive number of bac- teria shall be pasteurized. APPENDIX 361 General Regulations for Grade B. 1. Caps of bottles containing milk of Grade B shall be white and marked ''Grade B" in bright green letters, in large type. 2. Cans containing milk of Grade B shall have a tag affixed to each can with the words "Grade B" in large type, and the words of the subdivision to which the qual- ity of the milk in the said can conforms. GRADE C— FOR COOKING AND MANUFAC- TURING PURPOSES ONLY. Definition. Raw milk not conforming to the require- ments of any of the subdivisions of Grade A or Grade B, shall be handled according to the following requirements, rules and regulations : i. Milk of this grade shall not be sold at retail from stores. 2. Milk of this grade may be sold to restaurants, hotels, and manufacturing plants only. 3. Cans containing milk of Grade C shall be painted red on necks and shoulders, and shall have the words "Grade C" in large type affixed to each can. All creameries handling milk of different grades will be required to demonstrate to the department of health that they are capable of keeping the grades separate, and must keep records satisfactory to the department of health concerning the amount of milk of each grade handled each day. CONDENSED OR CONCENTRATED MIEK. Definition. This is milk' of any grade or subdivision thereof from which any part of the water has been re- 362 MARKET DAIRYING moved, or from which any part of the water has been removed and to which sugar has been added. Milk of this designation shall be sold only under a permit issued therefor. GENERAL RULES AND REGULATIONS. Permits. 1. A permit for the sale of milk or cream, of any grade or designation, may be granted only after an application has been made in writing on the special blank provided for the purpose. 2. A permit for the sale of milk, of any grade or designation, or of cream, may be granted only after the premises where it is proposed to care for and handle such milk shall have been rendered clean and sanitary. 3. Every permit for the sale of milk, or cream, from places other than wagons shall expire one year from the date of issue. 4. No wagon shall be used for the transportation of milk, condensed milk, or cream, without a permit from the board of health. Every such permit shall expire on the last day of December of the year in which it is granted. A wagon permit for the sale or transportation of milk, condensed milk, or cream shall be conspicuously displayed on the outside of the wagon so that it may be readily seen from the street. 5. Every permit for the sale of milk, of any grade or designation, in a store, shall be so conspicuously placed that it may be readily seen at all times. 6. All stores selling or keeping for sale milk, con- densed milk, or cream will be frequently inspected and APPENDIX 363 scored by a system adopted by the department of health, and the revocation of the permit of any store may ensue if the score is found repeatedly below the required stand- ard. 7. The revocation of a permit may ensue for violation of any of the rules and regulations of the department of health. 8. The revocation of a permit may ensue upon re- peated conviction of the holder thereof of the violation of any section of the Sanitary Code relating to the adul- teration of milk of any grade or designation. Sanitary Requirements. 1. Milk," condensed milk, or cream shall not be kept for sale nor stored in any stable or room used for sleep- ing or domestic purposes, or in any room if in commun- ication with such stable or room, or with watercloset apartments, except when such watercloset apartments are enclosed by a vestibule and are properly ventilated to the external air. 2. Milk, condensed milk, or cream shall not be sold or stored in any room which is dark, poorly ventilated, or dirty, or in which rubbish or useless material is al- lowed to accumulate, or in which there are offensive odors. 3. The vessels which contain milk, condensed milk, or cream, while on sale, must be so protected by suitable covers and so placed in the store that the milk, con- densed milk, or cream will not become contaminated by dust, dirt, or flies. 4. Cans containing milk, condensed milk, or cream 364 MARKET DAIRYING shall not be allowed to stand on the sidewalk or outside of the store door. 5. Milk, condensed milk, or cream must not be trans- ferred from cans to bottles or other vessels on the streets, at ferries, or at railroad depots. 6. Cans in which milk, condensed milk, or cream is kept for sale, shall be kept either in a milk tub, prop- erly iced, or in a clean ice-box or refrigerator in which these or similar articles of food are stored 7. All containers in which milk, condensed milk, or cream is handled, transported, or sold, must be thoroughly cleaned before filling, but such cleaning shall not be done, nor shall such containers be filled in any stable or in any room used for sleeping or domestic purposes, or in any room having connection with such stable or rooms, or with watercloset apartments, except when such water- closet apartments are enclosed by a vestibule and are properly ventilated to the external air. 8. All dippers, measures or other utensils used in the handling of milk, condensed milk, or cream must be kept clean while in use, and must be thoroughly cleaned with hot water and soapsuds directly after each day's use. 9. The ice-box or ice-tub in which milk, condensed milk, or cream is kept, must be maintained in a thoroughly clean condition, and must be scrubbed at such times as may be directed by the department of health. 10. The overflow pipe from the ice-box in which milk., condensed milk, or cream is kept, must not be directly connected with the drain pipe or sewer, but must dis- charge into a properly trapped, sewer-connected, water- supplied open sink. 11. No person having a contagious disease, or car- APPENDIX 365 ing for or coming in contact with any person having a contagious disease, shall handle milk. Labeling. Each container or receptacle used for bringing milk or cream into the city of New York, from which the said milk or cream is sold directly to the consumer, shall bear a tag stating, if shipped from a creamery, the location of the said creamery and the date of shipment ; if shipped di- rectly from a dairy, the location of the said dairy and the date of shipment. As soon as the contents of such container or receptacle are sold, or before the said container is returned or other- wise disposed of, or leaves the possession of the dealer, the tag thereon shall be removed and kept on file in the store where such milk or cream has been sold for a period of two months thereafter for inspection by the department of health. Every wholesale dealer in the city of New York shall keep a record in his main office in the said city, which shall show the place or places from which milk or cream, delivered by him daily to retail stores in the city of New York, has been received ; and the said record shall be kept for a period of two months for inspection by the depart- ment of health, and shall be readily accessible to the in- spectors of the said department. Pasteurisation. I. Milk, which has been subjected to the action of heat commonly known as "pasteurization," shall not be held, ke*pt, offered for sale, or sold and delivered in the 366 MARKET DAIRYING city of New York, unless the receptacle in which the same is contained is plainly labeled "Pasteurized." 2. Only such milk or cream shall be regarded as pas- teurized as has been subjected to a process in which the temperature and exposure conform to one of the fol- lowing: See page ill. 3. The milk after pasteurization must De at once cooled and placed in clean containers, and the containers immediately closed. 4. The said term "pasteurized" shall only be used in connection with the milk classified as "Grade A : selected Milk (Pasteurized)" and "Grade B: Pasteurized," or cream obtained from such milk. 5. Milk or cream which has been heated in any degree will not be permitted to be sold in New York City un- less the heating conforms with the requirements of the department of health for the pasteurization of milk or cream. 6. Applications for permits to pasteurize milk or cream will not be received until all forms of apparatus connected with the said pasteurization have been tested and the processes approved by the board of health. ' sTorch's TEST. This test makes it possible to determine whether milk, cream, skimmilk or buttermilk has been heated to 176 F. or above. It is made as follows : Put one teaspoonful of milk into a test tube, add one drop of 2% solution of peroxid of hydrogen and two drops of 2% solution of paraphenylenediamin ; shake the mixture ; if a dark violet color promptly appears, the milk has not been heated to 176 F. De Laval Milk Clarifier Next to the Cream Separator the most im- portant invention in the history of Dairy pro gr eSS— Statement of a National Dairy Authority. t| Milk clarified with the De sweet longer than milk not so DE LAVAL MILK CLARIFIER— Belt driven. Capacities 8,000 or 1 2,000 pounds per hour. Also furnished with steam turbine drive with same capacities. Laval Milk Clarifier will keep treated. 1$ Removes all free dirt, cow hairs and other objectionable foreign matter from milk, rendering it more wholesome and by the same token mak- ing it more marketable. €J The general introduction of these machines will greatly increase the consumption of milk. €| Requires less than one horse power to operate the 12,000 lbs. per hour ma- chine and it requires but lit- tle attention. C| Large milk dealers, con- denseries and cheese facto- ries will find it greatly to their advantage to investigate the merits of this machine. SEND FOR COMPLETE CATALOG De Laval Separator Company 165 Broadway, NEW YORK 29 E. Madison St., CHICAGO INDEX. Page Acid measures, sulphuric 52 Acids tests for milk and cream. 83 Acid test, rapid, for milk and cream 87 Aeration of milk and cream ... 39 Air, dust free 35 Albumen 13 Albumenoids 12 Appendix : . . . . 349 Ash 13 Babcock test 48 apparatus for 50 Babcock tester, calculating speed of 57 Babcock testers 4!», 58 Babcock test, making a 53 sample for 48 Bacteria, description of 20 Bacterial counts 232 Barn, sanitary 30 Bedding, clean 36 Bitter fermentation 25 Boiler and its management ....326 Boiler, care of / 332 firing of 330 pointers on 331 scale 334 Boric acid, detection of 195 Bottles as disease carriers 234 Bottling milk 122 Bulgaricus, bacillus 150 preparation and propaga- tion 150 Butter, composition of 349 dairy, marketing of 271 as a side line 133 granules 255 judging 202 marketing, creamery 267 dairy 271 overrun 274 Page Butter packages, paraffining. .. .265 packing of 263 salting of 255 score card 203 washing of 255 working of 258 Butterfat 9 composition of 10 globules 7, 9, 19 physical properties of 9 Buttermaking 239 Buttermilk, composition of 350 Butyric fermentation 24 Cans, shipping 129 Casein 12 Certified milk 183 Cheddar cheese making 278 cheese, marketing of 272 Cheese, cheddar, judging of.... 207 making 278 club 180 cottage 175 cream 180 factory dividends 2n.~i neufchatel 178 paraffining 283 pimento 182 ripening of 282 score card 208 whey or ricotta 181 Churning 249 conditions influencing ....249 difficult 260 operations 253 Churns, cleaning 260 City milk plants 320 City milk supply 226 Cold storage 97 air, forced circulation .... 99 anteroom for 97 insulation . 98 natural circulation in 100 369 370 INDEX Page Coloring butter 254 Colostrum milk 14 Composite sampling 59 Coolers, milk and cream 41 Cooling milk and cream 30 Cottage cheese 175 marketing 178 methods of manufacture ..175 packing 177 Cows, clean 31 Cream, acid tests for , 83 aging 167 bottles, Babcock 50, 71, 72 bottles, calibrating 57 cheese making 180 composition of 349 cooling of 39 detection of taints in 190 frequency of testing 70 judging of 200 keeping account of 220 pasteurization 104 regulating richness of .... 94 rich, advantages of 94 ripening 239 control of 244 methods of 241 natural 242 object of 239 pasteurized 242 starter 243 ripeners 247 samples, necessity of weigh- ing 70 sample, preparing of 73 samplers: «. 66 samples, composite 64 sampling 65 at creamery 69 at farm 68 scales 53, 71, 72 Shipping 128 standardizing 125 standards for cities 233 straining 254 tests, making of 73 reading of 73 Page Cream tickets 220, 225 weighing, at creamery...... 69 at farm 68 Creamery dividends .287 floor plan for ..270 statement 293 Creaming 90 centrifugal 92 gravity 90, 91 processes of 90 Cultured milk 147 Curdling and digesting fermen- tation 23 Curd test, Wisconsin 191 Dairy houses 312 Dirt, detection of 195 Dividends 287 Fggs as a side line 133 Farrington's acid test 85 Fat globules 19* Fats, insoluble 11 soluble 12 Fermentation test, Gerber 194 Flies 37 Fore-milk 36 Formaldehyde, detection of.... 196 Gassy fermentation 27 Homogenizer 167 Ice box 102 Ice cream, aging cream for.... 167 chocolate 162 condensed milk for 168 cost of 165 freezing process 158 fruit ice cream ..." 163 lemon 162 making of 157 marketing 166 nut 163 packing 163 plants 323 swell in 165 INDEX 371 Page Ice cream, use of gelatin in.... 164 vanilla 1G1 Ice house, construction of 340 insulated 101 Ice supply 339 Injector 328 Inspection at farm 228 in city 226 Insulation, cold storage 98 Judging butter 202 cheddar cheese 207 milk and cream 200 Lactic acid cultures 135 Lactic fermentation 22 Lacto 169 Lactometer and its use 7.">, 76 Manns' acid test 84 Marketing butter 263 cheese 272 dairy butter 271 milk and cream 121 pointers on 117 Metric system 351 Milk, acid tests for 83 adulterations 236 bottle, Babcock 50 bottles, calibrating 58 bottling 122 buying on fat basis 211 care of in home 216 certified 183 city, temperature and age regulations for 235 colostrum 14 composition of 8 cooling of . . . r 39 cultured 147 as a side line 133 marketing 152 method of manufacture. 149 therapeutic value of... 147 value as a drink 149 detection of dirt in 197 detection of preservatives in 195 Page Milk, detection of taints in 190 gassy, in cheese making ..283 heating before separating. . 95 houses (see dairy houses) fermentations 20 from different breeds .... 17 judging of 200 inspection at farm 229 keeping account of 220 microscopic appearance of . . 7 modified 170 preparation of 171 modifying in home 218 overripe, in cheese making. 285 pail sanitary 33 paying for at creameries. . .292 pasteurization of 104 physical properties of 7 plants 320 preservatives 60 rules and regulations for... 356 samplers 61 sanitary production of .... 29 score cards 200 secretion 14 selling on fat basis 211 shipping 128 skimming, detection of ... 80 specific gravity of 8 solids 77 calculation of 79 standardizing of 125 standards for cities 233 straining of 35 sugar 13 supply, control of city ..226 tickets 220, 225 tests, reading of 54 value, compared with its products 186 variations in quality of . . 15 watering of 80 Modified milk 170 Neufchatel cheese 178 methods of manufacture. .. 178 packing and marketing ...179 372 INDEX Page Overrun, butter 274 ice cream 165 Pimento cheese making 182 Pipette 52 Preservatives, detection of 195 Preservatives, for composite samples 60 Packing butter 263 Pasteurization : 104 advantages of, in butter making 242 for milk and cream.... 104 growing popular 105 held process Ill home 217 necessity of clean milk for. 112 objections to flash process .106 of milk and cream 104 processes 106 Pasteurized milk, low tem- perature for 112 Pasteurizing chart 107 in bottles 114 regulations Ill Refrigeration, mechanical 296 Refrigerator connected with ice house 101 ice box end 100 Ricotta cheese making 181 Salicylic acid, detection of.... 196 Salting butter 255 Samplers, cream 66 Samples, taking milk 59 Sampling, composite 59 cream 65 Sanitary milk production 29 Score card for butter 203 for cheese 208 for city milk plants 354 for farm dairies 352 for milk and cream 200 Sediment tester 197 Separators, fastening 95 Septic tank 343 Sewage disposal 343 Shipping cans 1 29 milk and cream 12S Page Side lines 132 Skimmilk bottle 51 Skimmilk — Buttermilk, manufac- ture of 154. as a side line 134 Skimmilk, composition of 350 Skimming milk, detection of . . 80 Slimy or ropy fermentation . . . 26 Standardizing milk and cream. 125 Starters 135 commercial 138 preparation of 138 mother 143 natural 136 natural vs. commercial 139 Steam 329 wet and dry 336 Sterilizing vessels 30S Strainers 35 Straining cream 254 Straining milk 35 Test bottles, cleaning of 56 Tester, Babcock 49,58 sediment 197 Testing composite samples .... 63 cream 65, 70 milk 48 Testjars 64 Themometer scales 350 Titration 83 Toxic fermentations 27 Tubercule bacilli in milk 231 Tuberculin test 229 benefits of . 231 Vanilla beans 160 flavor 159 Vessels as disease carriers 234 clean 32 washing of 306 Viscogen H3 Washing butter 255 vessels 306 Wash sinks 300 Water supply 337 Whey cheese (see ricotta cheese) Wisconsin curd test 191 The Vilter Manufacturing Co. (Established 1867) 877 Clinton Street ::: MILWAUKEE, WIS. " THE CREAM CITY " Buadc S CORLISS STEAM ENGINES Any horse power, Girder or Heavy Duty Type for Belted or Direct Connected Service. Medium or high speed, Vertical or Horizontal Slide Valve Engines, any size, Boilers, Heaters, Pumps, Etc. Vertical Single-Acting Refrigerating Machine for Belt Drive REFRIGERATING MACHINERY Vertical or Horizontal, for Dairies, Creameries, Ice Cream Plants, Cold Storage Houses, Markets or for Ice Making. Catalogs upon application. If interested in above machine ask for Bulletin H.-l 6