Class _ii'L2J^ Book >U Ccpight'N" ^04 COPYRIGHT DEPOSIT. Creanierj Butter Maliing BY JOHN MICHELS, B. S. A. (U. W.) INSTRUCTOR IN DAIRYING IN THE MICHIGAN STATE AGRICULTURAL COLLEGE SINCE 1900 ILLUSTRATED LANSING, MICHIGAN PUBLISHED BY THE AUTHOR I 904 ALL RIGHTS RESERVED K Sf Q S3 ii TRE LIBRARY OF OONGRESe, One OoFy Reoeivw MAY. C 1904 OfWVWeKT ENTUV . .r^v^ 1^0 5- X -- ^ 4 oorv B. COPYRIGHTED BY JOHN MICHELS 1904 PREFACE. The author's experience in teaching creamery students has demonstrated to him the need of a suitable reference book to be used in conjunction with the lectures on cream- ery butter making. An attempt to supply this need has resulted in the preparation of this work, which embodies the results of a long experience both as a practical butter maker and as a teacher of creamery management. Special emphasis has been laid upon starters, pasteur- ized butter making, methods of creamery construction, and creamery mechanics, subjects which have usually been treated only in a very elementary way in similar publica- tions that have appeared heretofore. The historical side of the various phases of butter mak- ing has in the main been omitted, not because it was deemed uninteresting, but for fear of making this volume too bulky. With the appended glossary explaining all unavoidable technical terms, this treatise is offered to the public as a suitable hand-book for the student as well as for the butter maker who cannot attend a dairy school. John Michels. Michigan Agricultural College, March, 1904. INTRODUCTION. The ''rule of thumb" butter making days are gone by. No one at the present time can hold any important posi- tion in the profession of butter making unless thoroughly grounded in the principles that underlie it. It is true many obscure problems yet remain to be solved, but by the aid of the bacteriologist and chemist butter making has now been fairly placed upon a scientific basis. Bacteriology has shed no less light upon the various processes involved in the manufacture of butter than it has upon the nature and causes of the diseases with which mankind is afflicted. The souring of milk, the ripening of cream, the causes of the various taints common to milk and cream are now quite thoroughly understood. Along with this understanding have come many radical changes in the handling of milk and cream and their manufacture into butter as well as in the handling of butter itself. The best butter makers at the present time are the men who are the most diligent students of bacteria and their relation to butter making processes. Above their doors is written in emblazoned letters "Cleanliness is next to Godliness." For cleanliness is the foundation of success in butter making. TABLE OF CONTENTS. Page Chapter I. Milk 1 1 Chapter II. The Babcock Test 23 Chapter III. The Lactometer and Its Use 34 Chapter IV. Bacteria and Alilk Fermentations 42 Chapter V. Coriiposite Sampling 51 Chapter VI. Creaming 57 Chapter VII. Cream Ripening 68 Part I. Theory and Methods of Ripening 68 Part II. Control of Ripening Process.... jT) Part III. Cream Acid Tests 81 Chapter VIII. Starters 88 Chapter IX. Churning 100 Chapter X. Packing and Marketing Butter 114 Chapter XI. Calculating Dividends 119 Chapter XII. Theoretical Overrun 128 Chapter XIII. Distribution of Skim-milk and Buttermilk. 130 Chapter XIV. Butter Judging 134 Chapter XV. Location and Construction of Creameries. . 141 a. [Model Creamery Illustrated 143 b. Cost of Building 158 c. Cost of Equipment 159 Chapter XVI. Creamery Mechanics 165 a. The Steam Boiler 165 b. The Steam Engine 179 c. Calculating Size and Speed of Pulleys. . 188 d. Friction : Its Advantage and Disad- vantage 191 e. Tools, Packing and Steam Fittings 194 f. Valves 196 g. Lining up Shafting 198 Chapter XVII. Pasteurization as Applied to Butter Making 200 Chapter XVIII. Co-operation . . . . „ 213 Chapter XIX. Detection of Tainted or Impure ]\Iilk 219 10 CONTENTS Page Chapter XX. Care of Milk and Skim-milk 223 Chapter XXI. Handling and Testing Cream 227 Chapter XXII. Mechanical Refrigeration 232 Chapter XXIII. Creamery Book-keeping 241 Appendix 250 Glossary 261 Index 265 CREAMERY BUTTER MAKING. CHAPTER I. MILK. IMilk, in a broad sense, may be defined 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. Moreover it contains these elements in the proper pro- portions and in easily di- gestible and assimilable form. Designed by Nature to nourish the young, milk was originally used entirely for this purpose and secre- ted only a short time after parturition. For many cen- turies, however, it has been used as an important part of the human dietary and cows at the present time yield milk almost incessantly. Because of its nutritive qualities its use as a dietetic is rapidly increasing. Physical Properties. Milk is a whitish opaque fluid possessing a sweetish taste and a faint ordor suggestive of cow's breath. It has an amphioteric reaction, that is, 11 Weigh can showing gate opener. 12 CREAMERY BUTTER MAKING 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 and 1.033. After standing a fev^ 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 87.1^ Butter fat 3-9^ Casein 2.9^ Albumen 5^ wSugar 4-9^ Ash •■ 7^ Fibrin Trace. Galactase Trace. 100. o'i The great variations in the composition of milk are shown by the figures from Koenig, given below : CREAMERY BUTTER MAKING 13 Maxiinuin. Miniuiuiii. Water 90-69 80.32 Fat 6.47 1.67 Casein 4-23 i-79 Albumen i . 44 .25 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 14 CREAMERY BUTTER MAKING 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 i . 90 Laurin 7.40 Myristin 20.20 Palmitin 25.70 Stearin i .80 Olein, etc 35-00 J 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. CREAMERY BUTTER MAKING 15 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 16 CREAMERY BUTTER MAKING 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 sokible 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. CREAMERY BUTTER MAKING 17 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 18 CREAMERY BUTTER MAKING 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 CREAMERY BUTTER MAKING 19 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. Alilk from dif- ferent sources may vary considerably in composition, particularly in the percentage of butter fat. Even the 20 CREAMERY BUTTER MAKING 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. QUALITY OF MILK 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. 1 4 2 4 3 4 4 4 5 4 6 4 7 4 8 4 9 4 10 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 CREAM BRY BUTTER MAKING 21 milk. The following data obtained at the New Jersey Experiment Station illustrates these differences: Breed. Total Solids. Fat. Milk Sugar. Proteids. Ash. Aysliire Guernsey Holstein Tersev Per cent. 12.70 14.48 12.12 14.34 Per cent. 3.68 5.02 3.61 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. OUAUTY 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 strippings 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. 22 CREAMERY BUTTER MAKING 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 dififerences 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 in stead of twice a day. 4. Unusual excitement of any kind reduces the quality of milk. The person wdio abuses cows by dogs, milk stools, or boisterousness, pays dearly for it in a reduction o? 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 afifect the richness of milk, but only temporarily. So long as cow^s 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. CHAPTER 11. the; babcock test. This is a cheap and simple device for determining the percentage of fat in milk, cream, skim-milk, buttermilk, whey, and cheese. It was invented in 1890 by Dr. S. M. Babcock, of the Wisconsin Agricultural Experiment Sta- tion, and ranks among the leading agricultural inventions of modern times. The chief uses of the Babcock test may be mentioned as follows : I. It has made possible the payment for milk accord- ing to its quality. ■ 2. It has enabled butter and cheese makers to detect undue losses in the process of manufacture. 3. It has made possible the grading up of dairy herds by locating the poor cows. 4. It has, in a large measure, done away with the prac- tice of watering and skimming milk. Principle of the Babcock Test. The separation of the butter fat from milk with the Babcock test is made possible : 1. By the difference between the specific gravity of butter fat and milk serum. 2. By the centrifugal force generated in the tester. 3. By burning the solids not fat with a strong acid. Sample for a Test. Whatever the sample to be tested, always eighteen grams are used for a test. In testing cream and cheese, the sample is weighed. For testing milk, skim-milk, buttermilk-, and whey, weighing requires 23 24 CREAMERY BUTTER MAKING too much time. Indeed, with these substances weighing is not necessary as sufficiently accurate samples are ob- Fig. l.-Babcock tester. tained by measuring which is the method universally em- ployed. In making a Babcock test it is of the greatest importance to secure a uniform sample of the substance to be tested. CREAMERY BUTTER MAKING 25 Apparatus. This consists essentially of the followin^s^ parts : A, Babcock tester ; B, milk bottle ; C, cream bottle : D, skim-milk bottle ; E, pipette or milk measure ; F, acid measures; G, cream scales; H, mixing cans; I, dividers. A. Babcock Tester. This machine, shown in Fig. i, consists of a revolving wheel placed in a horizontal posi- tion and provided with swinging pockets for the bottles. This wheel is rotated by means of a steam turbine wheel in the bottom or at the top of the tester. When the tester stops the pockets hang down allowing the bottles to stand up. As the wheel begins rotating the pockets move out causing the bottles to assume a horizontal position. Both wheels are enclosed in a cast iron frame provided with a cover. B. Milk Bottle. This has a neck graduated to ten large divisions, each of which reads one per cent. Each large division is subdivided into live smaller ones, making each subdivision read .2%. The contents of the neck from the zero mark to the 10% mark is equivalent to two cubic centimeters. Since the Babcock test does not give the percentage of fat by volume but by weight, the 10% scale on the neck of the bottle will, therefore, hold 1.8 grams of fat. In other words, if the scale were filled with water it would hold two grams ; but fat being only .9 as heavy, 2 cubic centimeters of it would weigh nine- tenths of two grams or 1.8 grams. This is exactly 10% of 18 grams, the weight of the sample used for testing. A milk bottle is shown in Fig. 2. C. Cream Bottles. These are graduated from 30% to 55%. A 30% bottle is shown in Fig. 3. Since cream usually tests more than 30%, the sample must be divided when the 30% bottles are used. 26 CREAMERY BUTTER MAKING Fig. 2.— Milk bottle. Fig. 3. — Cream bottle. .lfe,WMf?i^**74 Fig. 4.— SUim-milit bottle. D. Skim=milk Bottle. This bottle, shown in Fig. 4. 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. CREAMERY BUTTER MAKIXG 4/ i nSi \ Fi>f. 5. -Pi. petie. M Fig. 6 — Acid meas- ure. Fig. 7 - Acid meas- ure. E. Pipette. This holds 17.6 c.c, as shown in Fig. 5. Since about .1 c.c. of milk will adhere to the inside of the pipette it is ex- pected to deliver only 17.5 ex., 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. 6, holds 17.5 c.c. of acid, the amount needed for one test. The one shown in Fig. 7 is divided into six divisions, each of which holds 17.5 c.c. or one charge of acid. Where 28 CREAMERY BUTTER MAKING 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 scales commonly used is illustrated in Fig. 8. Acid. The acid used in the test is commercial sul- Fig. 8.— Cream sc^alcs. 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.9. -Show- ingmannerof emptying pi- pette. steps are CREAMERY BUTTER MAKING 29 ZZ^8 top and allow the milk to run down to the mark by slowly relieving the pressure of the finger. 3. Empty the milk into the bottle in the manner shown in Fig. 9. 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. 1 1 . Add moderately hot water un- til contents of the bottle reach about the 8% mark. 12. Whirl one minute. 13. Leave tester open a few min- utes. 14. Read test. How to Read the Test. At the top of the fat column is usually quite a pronounced meniscus as shown in Fig. 10. A less pronounced one is found at the bottom of the column. The fat should be read from the extremes of the fat column, i to 3, not from 2 to 4, when its temperature is about 140° F. Too high a temperature gives too high Fig. 10.— Fat column showing meniscuses. 30 CREAMERY BUTTER MAKING a reading, because of the expanded condition of the. fat, while too low a temperature gives an uncertain reading. S bis I g'7 !o^ Fig. 12.— Milk bot- tle tester. Fig. 11. — Waste acid jar. Precautions in Making a Test. i. Be sure you have a fair sample. 2. The temperature of the milk should be about 6o or yo degrees. 3. Always mix twice after acid has been added. 4. Be sure your tester runs at the right speed. CREAMERY BUTTER MAKING 31 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 afifects 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 bottle should be emptied into an earthen jar (covered with a perforated board) by shaking it up and down so as to remove the white sediment. (Fig. 11.) It is now rinsed with one-third pipetteful of cleaning solution, which is made by dissolving about an ounce of potassium bichromate in one pint of sulphuric acid. Next run test bottle brush once up and down the neck of the bottle and finally rinse with hot water. 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. 12, 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. 32 CREAMERY BUTTER MAKING 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 i c.c. when immersed in the liquid, hence the two sections will just fill the scale if the latter is correct. 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 : Diameter of No. of revolutions zvheel of zvheel in inches. per minute. 10 1,074 12 980 14 909 16 848 18 800 20 759 22 724 24 693 General Pointers. Black fat is caused by 1. Too strong acid. 2. Too much acid. 3. Too high a temperature of the acid or the milk. 4. Not mixing soon enough. 5. Dropping the acid through the milk. . Foam on top of fat is caused by hard water, and can be prevented by adding a few drops of sulphuric acid to the water. CREAMERY BUTTER MAKING 33 Unclean or cloudy fat is caused by 1. Insufficient mixing. 2. Too low speed of tester. 3. Too low temperature. 4. Too weak acid. Curd particles in fat are caused by 1. Too weak acid. 2. Not enough acid. 3. Too low temperature. CHAPTER III. THE LACTOMETER AND ITS USE. This instrument, shown in Fig. 13, 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 w^eighted with shoti 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. 14.) 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 60°. 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 34 CREAMERY BUTTER MAKING 35 ojic-tcnth of a lactometer degree for every degree of teui- peratiire 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. 13. LiHCtom eter. Fig. 14.— Lactom- eier 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 ^2. 2. Lactometer reading is 31.7 at a temperature of 67^, Corrected reading is 31.7 plus .3, equals ^2, Interpretation of Lactometer Reading. In the chap- ter on milk we learned that normal milk has an average 36 CREAMERY BUTTER MAKING 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 i.o is omitted. A reading of 32, expressed in terms of specific gravity, would therefore read 1.032. Precautions in Making a Lactometer Test. i. 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 ofif 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 : 3-9^ fat 2.9^ casein 0.5^ albumen 4-9^ sugar 1 0.7^ ash Total 12.9,^ =total solids. CREAMERY BUTTER MAKING 37 g.'^= solids not fat. 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 Slykc. Per cent fat. Per cent casein. 3.00 2.10 3 25 2 . 20 50 2.30 75 2.40 00 2 . 50 25 2 . 60 50 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 38 CREAMERY BUTTER MAKING 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 : 1. 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 o Q ^ v —J— plus ~tr) equals (7.9 plus .7) equals 8 6 equals solids not fat. 2. The total solids in the above sample are obtained \)\ adding the fat and solids not fat. Thus: 8.6 plus 3.5 equals 1 2. 1 equals total solids. CREAMERY BUTTER MAKING 39 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 butter makers, 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 creamery. 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 : 40 CREAMERY BUTTER MAKING 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 : CREAMERY BUTTER MAKING 41 I. Suspected sample shows: Xormal milk shows: Lactometer reading 32 Lactometer reading 32 Fat 2.5 Fat 3-9 Solids not fat 8.5 Solids not fat 8.7S 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 IV. BACTERIA AND MILK FERMENTATIONS. A thorough knowledge of bacteria and their action forms the basis of success in butter making. Indeed the man who is lacking such knowledge is making butter in the dark ; his is chance work. Much attention will therefore be given to the study of these organisms in this work. I. BACTERIA. The term bacteria is applied to the smallest of living plants, which can be seen only under the highest powers of the miscroscope. Each bacterium is made up of a single cell. These plants are so small that it would require 30,000 of them laid side by side to measure an inch. Their presence is almost universal, being found in the air, water, and soil ; in cold, hot, and temperate climates ; and in living and dead as well as inorganic matter. Bacteria grow with marvelous rapidity. A single bac- terium is capable of reproducing, itself a million times in twenty- four hours. They reproduce either by a simple division of the mother cell, thus producing two new cells, or by spore formation in which case the contents of the mother cell are formed into a round mass called a spore. These spores have the power of withstanding unfavorable conditions to a remarkable extent, some being able to endure a temperature of 212° F, for several hours. Most bacteria require for best growth a moist, warm, and nutritious medium such as is furnished by milk, in 42 CREAMERY BUTTER MAKING 43 which an exceedingly varied and active life is possible. In nature and in many of the arts and industries, bacteria are of the greatest utility, if not indispensable. They play a most important part in the disintegration of vegetable and animal matter, resolving compounds into their elemental constituents in which form they can again be built up and used as plant food. In the art of butter and cheese making bacteria are indispensable. The to- bacco, tanning, and a host of other industries cannot flourish without them. II. MILK FERMENTATIONS. Definition. In defining fermentation processes, Conn says that, "In general, they are progressive chemical changes taking place under the influence of certain organic substances which are present in very small c[uantity in the fermenting mass." With few exceptions, milk fermentations are the result of the growth and multiplication of various classes of bacteria. The souring of milk illustrates a typical fer- mentation, which is caused by the action of lactic acid bacteria upon the milk sugar breaking it up into lactic acid. Here the chemical change is conversion of sugar into lactic acid. The most common fermentations of milk are the fol- lowing: : ]\lilk Fermentations J [" Lactic. Normal -| Curdling and Digesting. I Bntj-ric. f Bitter. I Slimy or Ropy. Abnormal... ^ Gassy '- I Toxic. I Chromoge nic. 44 CREAMERY BUTTER MAKING NORMAL FERMENTATIONS. We Speak of normal fermentations because milk always contains certain classes of bacteria even when drawn and kept under cleanly conditions. These fermentations will be discussed in the following pages. 1. LACTIC FERMENTATION. This is the most common and by far the most important fermentation of milk. Indeed it is indispensable in the manufacture of butter of the highest quality. The germ causing this fermentation is called Lactici Acidi. It is non-spore bearing and has its optimum growth tempera- ture between 90° and 98° F. At 40° its growth ceases. Exposed to a temperature of 140° for fifteen minutes it is killed. The souring of milk and cream, as already mentioned, is due to the action of the lactic acid bacteria upon the milk sugar changing it into lactic acid. x\cid is therefore always produced at the expense of milk sugar. But the sugar is never all converted into acid because the pro- duction of acid is limited. When the acidity reaches about .9% the lactic acid bacteria are either checked or killed and the production of acid ceases. Owing to the universal presence of these bacteria it is almost impossible to secure milk free from them. Under cleanly conditions the lactic acid type of bacteria always predominates in milk. When, however, miik is drawn under uncleanly conditions the lactic organisms may be outnumbered by other species of bacteria which give rise to the numerous taints often met with in milk. Contradictory as it may seem, the lactic acid bacteria are alike friend and foe to the butter maker. Creamery CREAMERY BUTTER MAKIXG . 45 patrons are expected to have milk as free as possible from these germs so that it may arrive at the creamery in a sweet condition. They are therefore expected to thoroughly cool and care for it, not alone to suppress the action of the lactic acid bacteria but also that of the abnormal species that might have gained access to the milk. \Miile the acid bacteria are objectionable in milk, in cream made into butter they are indispensable. The highly desirable aroma in butter is the result of the growth of these organisms in the process of cream ripening. There are a number of dififerent species of bacteria that have the power of producing lactic acid. 2. CURDLING AND DIGESTING FERMENTATION. In point of numbers this class of bacteria ranks perhaps next to the lactic acid type. Indeed it is very difficult to obtain milk that does not contain them. It is not often, however, that their presence is noticeable owing to their inability to thrive in an acid medium. According to bacteriologists most of these bacteria secrete two enzymes, one of wdiich has the power of curdling milk, the other of digesting it. The former has the power of rennet, the latter of trypsin. "As a rule," says Russell, "any organism that possesses the digestive power, first causes a coagulation of the casein in a manner comparable to rennet." It is onl}- occasionally when the lactic acid organisms are in a great minority, or when for some reason their action has been suppressed, that this class of bacteria manfests itself by curdling milk while sweet. The curd thus formed differs from that produced by lactic acid in being soft and slimy. 46 CREAMERY BUTTER MJKIXG Most of the curdling and digesting bacteria are spore bearing and can thus witlistand unfavorable conditions better than the lactic acid bacteria. For this reason milk that has been heated sufficiently to kill the lactic acid bacteria, will often undergo the undesirable changes attributable to the digesting and curdling organisms. 3. BUTYRIC Fi=;rme;ntaT]on. It was mentioned that many bacteria have the power of producing lactic acid but that the true lactic acid fer- mentation is probably caused by a single species. So it is with the butyric acid bacteria. While a number of different organisms are known to produce this acid. Conn is of the opinion that the common butyric fermentation of milk and cream is due to a single species belonging to the anaerobic type. The butyric acid produced by these organisms is the chief cause of rancid flavors in cream and butter. These bacteria are widely distributed in nature, being particu- larly abundant in filth. They are almost universally present in milk, from which they are hard to eradicate on account of their resistant spores. It is on account of these spores and their ability to grow in the absence of oxygen that the butyric fermentation is often found in ordinary sterilized milk from which the air has been excluded. This cl-ass of bacteria has great significance in cream ripening and in the keeping quality of butter. In the ripening of cream the desirable flavor develops with the increase of acidity until the latter has reached .6%. When the development of acid goes beyond this, the flavor is no longer of the desirable kind but turns rancid as a result of the development of the butyric fermentation. CREAMERY BUTTER MAKING 47 The butyric fermentation is rarely noticeable durinp^ the early stage of cream ripening and its subsequent development in a highly acid cream is explained by Russell as being "probably due, not so much to the pres- ence of lactic acid, as to the absence of dissolved oxygen, which at this stage has been used up by the lactic acid organisms." Butter that is apparently good in quality when freshly made, w^ill usually turn rancid when kept at ordinary temperatures a short time. The quickness with which this change comes is dependent largely upon the amount of acid present in cream at the time of churning. Butter made from cream in which the maximum amount of acid consistent with good flavor has been developed, usually possesses poor keeping quality. This seems to indi- cate that at least part of the rancidity that develops in butter after it is made is due to the butyric acid bacteria, while light and air, doubtless, also contribute much to this end. ABNORMAL FERMENTATIONS. No trouble needs to be anticipated from these fermenta- tions so long as cleanliness prevails in the dairy. The bacteria that belong to this class are usually associated with filth, and dairies that become infested with them show a lack of cleanliness in the care and handling of the milk. Since milk is frequently infected with one or another of these abnormal fermentations a brief discus- sion will be given of the most important. I. BITTER FERMENTATION. Bitter milk and cream are quite common and there are several ways in which this bitterness is imparted : it may 48 CREAMERY BUTTER MAKING be due to strippers' milk and to certain classes of feeds and weeds, but most frequently to bacteria. This class of bacteria has not yet been studied very thoroughly but we know a great deal about it in a practical way. In milk and cream in which the action of the lactic acid germs has been suppressed by low temperatures, bitter- ness due to the development of the bitter fermentation is almost certain to be noticeable. When the temperature is such as to cause a rapid development of the lactic fermentation, the bitter fermentation is rarely, if ever, present. It is quite evident from this that the bitter organisms are capable of growing at much lower tem- peratures than the lactic and that so long as the latter are rapidly growing the bitter fermentation is held in check. This teaches us that it is not safe to ripen cream below 60° F. The author has found that cream quickly ripened and then held at a temperature of 45° for twenty-four hours would show no tendency toward bitterness, while the same cream held sweet at 45° for twenty- four hours and then ripened would develop a bitter flavor. This indicates that the lactic acid is unfavorable to the develop- ment of the bitter fermentation. The bitter germs produce spores capable of resisting the boiling temperature. This accounts for the bitter taste that often develops in boiled milk. • 2. SUMY OR ROPY FERMENTATION. This is not a common fermentation and rarely causes trouble where cleanliness is practiced in the dairy. The bacteria that produce it are usually found in impure water, dust, and dung. These germs are antagonistic to CREAMERY BUTTER MAKING 49 the lactic organisms and for this reason milk infected with them sours with great difficulty. The action of this class of bacteria is to increase the viscosity of milk, which in mild cases simply assumes a slimy appearance. In extreme cases, however, the milk develops into a ropy consistency, permitting it to be strung out in threads several feet long. Slimy or ropy milk cannot be creamed and is therefore worthless in the manufacture of butter. Such milk should not be confused with gargety milk which is stringy when drawn from the cow. The bacteria belonging to this class are easily destroyed as they do not form spores. 3. GASSY fe:rmentation. This is an exceedingly troublesome fermentation in cheese making and is also the cause of much poor flavored butter. The gas germs are very abundant during the warm summer months but are scarcely noticeable in winter. Like the bitter germs, they are antagonistic to the lactic acid bacteria and do not grow during the rapid development of the latter. They are found most abun- dantly in the barn, particularly in dung. 4. TOXIC FERMENTATIONS. Toxic or poisonous products are occasionally developed in milk as a result of bacterial activity. They are most commonly found in milk that has been kept for some time at low temperature. 5. CHROMOGENIC FERMENTATIONS. Bacteria belonging to this class have the power of imparting to milk various colors. The most common of 50 CREAMERY BUTTER MAKING these is blue. It is, however, not often met with in dairy practice since the color usually does not appear until the milk is several days old. The specific organism that causes blue milk has been known for more than half a century and is called cyanogenous. Another color that rarely turns up in dairy practice is produced by a germ known as prodigiosis, causing milk to turn red. Other colors are produced such as yellow, green, and black, but these are of very rare occurrence. Fig. 15— Composite test jar. ;HAPTER V. 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. 15. 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. 51 52 CREAMERY BUTTER MAKING Most of the sampling is done by either of two methods : (i) by means of a half ounce dipper, shown in Fig. i6, or (2) by means of long narrow tubes, one of which is shown in Fig. 17. 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. 17). 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 Equity sampler designed by Kolarik, works on the 'same principle as the Scovell and has proven very satis- factory. Preservatives. Milk cannot be satisfactorily tested after it has loppered owing to thhe 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 CREAMERY BUTTER MAKING . 53. Fig. ItD.— Milk sampler. Fig. 17 — Scovell sampling 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 twc 54 CREAMERY BUTTER MAKING 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 butter maker owes his patrons to keep the sample jars carefully locked up 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 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- CREAMERY BUTTER MAKING 55 served that the butter maker ( ?) did not cover the jars at all ! Can we wonder why patrons complain so fre- quently about the testing? Where the jars are kept uncovered for several 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 iio° 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 56 CREAMERY BUTTER MAKING that month. On the weekly basis of testing there would still be three tests to fall back on. Supervision of Test. To relieve the butter maker from any suspicion of unfairness or carelessness in the testing of the composite samples, one or two of the patrons should be present at each testing. When one of the patrons thus witnesses the details of the testing and is furnished with a copy of the test, the butter maker is practically exempt from the suspicions that usually rest upon him, no matter how honest or careful a man he may be. Duplicate Set of Jars. Where the testing is not under the supervision of one of the patrons, some butter makers have adopted the scheme of providing a double set of sample jars. After the test is made the jars, instead of being emptied, are set aside for a week, so that any- one who has any complaint to offer on the test may call on the buttermaker for a retest, another set of sample jars being used in the meantime. CHAPTER VL CREAMING. Definition. 'Milk upon standing soon separates into two portions, one called cream, the other skim-milk. This process of separation is known as creaming, and is due to the difference in the specific gravity of the fat and the milk serum. The fat being light and insoluble, rises, carrying with it the other constituents in about the same proportion in which they are found in milk. The fat together wnth these other constituents forms the cream. After the cream has been skimmed off, there remains a more or less fat- free watery portion called skiui-milk. 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 eft'ect 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. Before the days of the centrifugal cream separator, creameries either bought the milk and creamed it at the creamery by the gravity process* or bought and gathered the cream that had been creamed at the farms by the same process. The method of cream gathering is still exten- sivelv employed by creameries ; indeed in many sections 57 58 CREAMERY BUTTER MAKING of the country this practice is actually growing. Cream thus gathered is, however, largely the product of the cream separator, only a small portion being still creamed bv the gravity process. The discussion on creaming will therefore be confined to the centrifugal process. CREAM SEPARATORS. History. The cream separator had its beginning in 1864 when Prandtl, of Munich, creamed milk by means of two cylindrical buckets revolving upon a spindle. In 1874 Lefeldt constructed a separator with a revolving drum similar to the later hollow bowl separators. This drum had a speed of 800 revolutions per minute. But it lacked an arrangement permitting a continuous discharge of cream and skim-milk, so that the separator had to be stopped at regular intervals when the cream was skimmed ofif, the skim-milk removed, and the bowl refilled for the next separation. It was not until 1879 that real separators appeared upon the market. During this year two machines were perfected which permitted continuous creaiii and skim- milk discharges. One was known as the Danish Weston, invented in Denmark, the other the De Laval, invented in Sweden. Both of these separators were hollow bowl machines. Other separators soon followed but no decided improve- ment was made until 1891, when the De Laval separator, shown in Fig. 18, appeared with a series of discs inside the bowd which had the. efifect of separating the milk in thin layers, thus increasing 'both the efficiency and the capacity of the separator. Since then various bowl devices have been invented bv numerous separator manufacturers. CREAMERY BUTTER MAKING 59 In 1896 a hollow bowl separator was again placed upon the market, this time by the Sharpies Company. This separator had a long, narrow, suspended bowl, revolving about 24,000 times per minute, in which the efficiency of skimming was greater than that in the old hollow bowl style of separators. Fig. 18.— De Laval cream separator, Fig. 19.— Sharpies cream separator. In 1902 this company introduced another separator with a bowl of about the same construction but filled with a core made up of numerous sections which allowed the speed to be reduced to 14,000 revolutions per min- ute. This is a turbine separator a cut of which is shown in Fig. 19. Numerous other power separators have been in use for many years, chief among which may be mentioned the United States and Reid. 60 CREAMERY BUTTER MAKING Hand separators first appeared on the market in 1886. They are extensively used on dairy farms at the present time and are rapidly replacing the gravity methods of creaming. In 1887 a machine appeared on the market which ex- tracted the butter directly from sweet milk. This machine was called butter extractor. The butter made with the extractor was inferior in quality and the machine has practically gone out of existence. Choice of Separator. In choosing a cream separator we should be guided by three things: i. Efficiency of skimming ; 2. Power required to operate ; 3. Its durability. I. EFFICIENCY OF SKIMMING. 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- in??, other conditions the same. It is important to see CRBAMHRY BUTTER MAKING 61 that the separator runs at full speed during the separating- process. The speed indicator should always be applied before turning on the milk and several times during the run. Loose belts, pulleys slipping on the shaft, and low steam pressure will reduce the speed of the separator. 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: (i) loose bearings, (2) sepa- rator out of plum, (3) dirty oil or dirty bearings, (4) un- stable 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° F. is the most satisfactory for ordinary skimming. Under some conditions the cleanest skimming is obtained at temperatures above 100° 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 in ordinary skimming. 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 temperature 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. If, instead of suddenly heating the milk to 85°, it is heated to 160° or above, then no extra loss of fat occurs. Hence the ad- vantage of separating milk at pasteurizing temperature during the winter. 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. 62 CREAMERY BUTTER MAKING 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. This emphasizes the importance of having the milk delivered to the creamery in a sweet condition. 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- 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. 2. POWER REQUIRED TO OPERATE. This is a matter of importance as a heavy running machine will add much to the running expenses of the creamery. Such a machine will not only require more fuel but will increase the wear of belts and machinery. 3. DURABILITY. Cream separators are expensive machines and due re- gard should be given to their wearing qualities. They should be made of the best material, possess good work- manship, and have as few wearable parts as possible. CREAMERY BUTTER MAKING 63 SEPARATING TEMPERATURE. During the summer time, when milk is fresh and re- quires Httle heating, a separating temperature of 70° F. gives good results. In the late fall and during the winter, when milk is received cold and often two days old, it is necessary to raise the temperature of the milk to 85° before separating. When milk is received in a partly frozen condition or when permeated with bad odors, a separating temperature of 140° to 170° is pre- ferred. Whenever such high temperatures are employed it is necessary .to cool the cream immediately after it leaves the separator to a temperature of 70° or lower. RICHNESS OF CREAM. How Regulated. The richness of cream is usually regulated by means of a cream screw in the separator bowl. When a rich cream is desired the opening in the screw is turned toward the center of the bowl, and for a thin cream it is turned away from the center. In some machines the richness of cream is regulated by the rate of separation. With all separators the more milk separated per hour and the lower the speed the thinner the cream. Too low a speed always results in a rich skim-milk and poor cream. Temperatures between 60° and 90° have little effect on the richness of cream. Wlien, however, the tempera- ture is raised to 140° or above , the cream becomes thinner. Advantages of Rich Cream. These may be summed up as follow^s : 1. Permits the use of more starter. 2. Contains fewer objectionable bacteria. 64 CREAMERY BUTTER MAKING 3. Can be churned at a lower temperature. 4. Occupies less space. 5. There is less cream to cool. Where a large amount of starter is to be added to the cream it is necessary to separate a rich cream so that the starter will not bring it below the churning richness. Fig. 2J.-Cuitis milk heater. In case milk is tainted it is desirable to separate a very heavy cream so as to get rid of as much milk serum as possible. In this way we get rid of most of the taint, which develops in the milk serum. The cream is then reduced to churning richness w^ith starter, or partly with starter and partly with fine flavored milk. The fat globules in a rich cream are close together which permits churning at a comparatively low tempera- ture. The chief advantage gained in this is the greater exhaustiveness of churnin.sr. CREAMERY BUTTER MAKIXG 65 MILK HEATERS. There are to be found upon the market two general classes of milk heaters : Those which admit the steam directly to the milk called direct heaters, and those in which the steam enters a jacket surrounding the milk known as indirect heaters. Direct Heaters. These are practically nothing more than an expansion in the feed pipe in which the steam Fig- 21.— Twentieth Century milk heater. enters the milk. They are permissible only when first class steam is available and when milk is to be heated through a short range of temperature. But even under these conditions indirect heaters are always preferred. 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 temperature. Indirect Heaters. Figs. 20 and 21 illustrate this type of heaters. In the Curtis heater the milk circulates in a 66 CREAMERY BUTTER MAKING thin sheet between an inner removable cyHnder and the inner wall of the steam jacket, thus heating it gradually as it passes from one end to the other. In the Twentieth am^ Fig. 22.— Reid pasteurizer. Figr. 23.— Bair cream cooler. Century heater the steam passes inside a series of discs. These discs are in motion during the heating and force the milk into the separator. Another type of indirect heater is the Reid pasteurizer shown in Fig. 22. This machine not only heats the milk but elevates it, thus dis- pensing with the use of a milk pump. CREAMERY BUTTER MAKING 67 CREAM COOLERS. With the modern cream ripeners described in Chapter VII no special cream cooler is necessary since the cooling is very quickly done in the ripener. With open vats placed on the same floor with the separators the most practical cooler is that belonging to the Bair type, which is illustrated in Fig. 23. This cooler is from six to eight feet long, about one foot wide, and three inches deep. The top of the cream vat need there- fore not be more than four inches lower than the cream spout of the separator. The circulation of the water is indicated by the arrows, the water entering the cooler at the point at which the cream leaves it. The surface over which the cream flows is slightly corrugated, thus increasing the amount of cooling surface. This cooler will cool cream within ten degrees of the temperature of the water when separated at ordinary temperatures. CHAPTER VII. CREAM RIPENING. 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, 68 CREAMERY BUTTER MAKING 69 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%. From this it might appear that all of the flavor is inher- ent in the lactic acid itself. But this is not the case. The souring of milk free from fat does not produce the flavor found in sour cream, though the acid is the same in both cases. The view held by Duclaux is perhaps the most satisfactory in explaining the origin of the flavor produced in cream ripening. He maintains that since some caproic and butyric acids always exist in a free state in butter, the flavor may be the result of the forma- tion of caproic and butyric ethers from these acids. The formation of such ether compounds in cream would doubtless be due to the presence of lactic acid. And it can not be denied that the lactic acid itself figures as one of the components of butter flavor. 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 viscositv impedes the movement of these globules. It is 70 CREAMERY BUTTER MAKING 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 pasteiirizcd cream ripening. CREAMERY BUTTER MAKING 71 3. By the aided development of the lactic fermenta- tion called starter ripening. I. NATURAL RIPENIN0. 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 60° 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 72 CREAMERY BUTTER MAKING 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 vmiversally 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 CREAMERY BUTTER MAKING 73 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 wdien 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 OF 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. ]\Ieans of controlling tem- perature. I. 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 efifect of a starter it should be added to the cream vat soon after the separation 74 CREAMERY BUTTER MAKING 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 I "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 80°. Temperatures below 60° 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 CREAMERY BUTTER MAKING 75 the best results. This means that the main portion 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 76 CREAMERY BUTTER MAKING one and will be discussed under the head of cream ripeners. CREAM RIPENERS. ~~ During the summer months much butter of inferior quality is made bv overnpenmj the cream and churning at too high a temperature. This is due chiefly to a lack of proper cool- ing facilities. With the open cream vats the control of temperature is a difficult thing. For- tunately these vats are being replaced by the more modern cream ripeners of which the Farrington and the Boyd are Fig. :i4.— Boyd cream ripener. Fig. 25.— Farrington cream ripener CREAMERY BUTTER MAKING 77 types. These ripeners possess two important advantaf:^es over the open vats, namely : first, they permit a niore rapid cooHng by agitating the water and cream while cooling ; second, they maintain a more uniform temperature be- cause of tight fitting covers and better all round construc- tion. With the Boyd ripener, shown in Fig. 24, the cooling is done by running cold water through a series of tinned-iron pipes which are inserted in the cream and kept moving to and fro by means of power attachment. The cooling in the Farrington vat is accomplished by circulating cold water in a jacket surrounding the cream. The vat is of cylindrical shape and is ro- tated by power during cooling. The Farrington ripener and air com- pressor for forcing the cream into the churn are shown in Figs. 25 and 26. Since these ripeners are so con- structed as to render the addition of ice to the water in them im- possible, they can not be considered complete without an ice water at- tachment. In Fig. 2y an ice water tank may be seen attached to the Boyd ripener. Ice water may be circulated in the same way with the Farrington 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 Fig. 26.— Air compressoi". 78 CREAMERY BUTTER MAKING 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 140 times as much cold as Fig. 27.— Showing method of circulating ice water through ripener. one pound of water raised from 32° to 2)Z° F. In other words, the cooling power of ice is 140 times as great as that of water. To get at the amount of ice necessary in cooling cream with ice a series of tests was made with a 400 gallon Farrington ripener, which was carried out as follows : As soon as about thirty-five gallons of cream was sepa- rated, the ripener was set in motion and a continuous stream of cold water kept flowing through it until all the cream was separated. Further cooling was then de- layed for three or four hours when the ripener was again started and iced water allowed to circulate through it by means of a common rotary pump. The results thus secured are set forth in the following table : CREAMERY BUTTER MAKIXG 79 Results obtained zcith a 400 gallon Farrington Cream Ripener. COOLING WITH ICED WATER. Gallons cream. 0) o a So, a c3 « 260 64° 260 260. 5»° 64° 260 61° 260 59° 260. . . . 60° 260 59° 260. 58° 260 66° 260 260. . 58° 58° 260 62° . 1 0-, ■ -^ August 15 3.4 . 4.3 3.6 August 23 3.4 4.2 2>1 August 31 Z2, 40 3.6 4| 13.4 4| 16.7 4| 14-5 Average test. .. . 3.35 4.17 3.62 CREAMERY BUTTER MAKING 121 4- Total milk. Ave. test. Total butter fat. A 8,091 X 3.35 = 27i.05lbs. B 4,650 X 4.17 = 193.91 lbs. C 9,405 X 3-^^ = 340.46 lbs. Total butter fat at Creamery = 805.42 lbs. Sales of butter. 205 lbs. at 22, cts. = $47-15 240 lbs. at 23.5 cts. = 56.40 214 lbs. at 24 cts. = 51.36 269 lbs. at 24 cts. = 64.56 Total... 928 Total $219-47 6. Total pounds of butter = 928. Price charged for making = 3 cts. per pound. 928 X .03 = $27.84 = Amount charged to cover running expenses. 7. $219.47 — $27.84 = $191.63 = Net money due patrons. 8. $191.63 ^805.42 = $.2379 = Average price per pound but- ter fat. 9. 271.05 X $.2379 = $64.48 = A's money. 193.91 X .2379= 46.13 = B's money. 340.46 X .2379= 81.00= C's money. OVERRUN. In a well conducted creamery the total pounds of butter is always greater than the total pounds of butter fat. The excess is called the "overrun." In the above problem 805.42 pounds of butter fat made 928 pounds of butter. 928.00 — 805.42 = 122.58 = No. pounds overrun. 122.58-^805.42= 15.2 = Per cent overrun. 122 CREAMERY BUTTER MAKING MONTHLY STATEMENT. When the monthly payments are made each patron is presented with an envelope upon which is printed his indi- vidual 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." Below is shown such a monthly statement: CREAMERY BUTTER MAKING 123 Creamery Co. Mr. IN ACCOUNT WITH For ttie me M\t\\ of 190 No. lbs. milk delivered Cr. Lbs. butter. . Cans @ @... Dr. hv vou - . - Average test No. lbs. of bu Price per lb. Cash, Hauling, @.. per 100 lbs. - - . tter fat, . . . $. ^^ ^ p X 1 X a X n . H- p- = — mm — ^^ ^^^^^ P = Mean effective steam pressure. 1 = length of stroke in feet, a = area of piston in square inches. - n = number of strokes per minute. H. P. = Horse power. 33,000= Number of foot-pounds. A foot-pound is one pound raised through one foot of space. Length of stroke = twice the length of crank. No. of strokes per min. = twice the number of revolutions. 188 CREAMERY BUTTER MAKING c ■ -^^^ Area of piston = -j-- Example : P = 40 lbs. 1 = 2 ft. a = 20 sq. inches. n = 400. 40 X 2 X 20 X 400 = 640,000 640,000 -^ 33,000 = 19.4 = H. P. CALCULATING SIZE AND SPEED OF PULLEYS. In creameries where new shafting and new machinery are being put up, it is important to know how to determine the required speed of the shafting as well as the speed and size of the pulleys. This calculation is not difficult when we remember the following rule: The speed varies inversely with the diameter of the pulley. Thus, with the same speed of the engine, the speed of the main shaft becomes less as the diameter of the pulley on that shaft is increased. It must be remembered, also, that in a creamery where the churn and separators are run directly from the main shaft, the speed of this shaft must be fixed at from 175 to 200 revolutions per minute in order to permit the use of suitable sized pulleys. We usually speak of two kinds of pulleys: the drive pulley and the driven pulley. Where the engine drives the main shaft the pulley on the engine is called the drive pulley and that on the main shaft the driven pulley. When we refer to the main shaft driving the intermediate, then the pulley on the main shaft becomes the driver and that on the intermediate the driven pulley. In creameries there are two problems that present them- selves with respect to pulleys : one is to find the speed of CREAMERY BUTTER MAKING 189 the pulley when the diameter is given ; the other is to find the diameter when the speed is given. I. To find the speed of a driven pulley : IMultiply the diameter of the driver by its speed and divide the product by the diameter of the driven pulley. Fig. 54.— Belting from engine to separator. Example : Diameter of engine pulley, 20 inches ; speed of engine, 200 revolutions per minute ; diameter of driven pulley, 25 inches. 20 X 200-^25 = 160= No. rev. per min. of driven pulley. 2. To find diameter of driven pulley: Multiply the diameter of driver by its speed and divide the product by the required speed of driven pulley. Example : Diameter of engine pulley, 20 inches ; speed of engine, 200 revolutions per minute; speed of driven pulley, 200 revolutions per minute. 20 X 200 ^ 200 = 20 = diameter of driven pulley. 190 CREAMERY BUTTER MAKING Let us calculate the size and speed of pulleys neces- sary to run a separator 6,000 revolutions per minute when the following conditions are knovv^n : Size of drive pulley on engine, 16 inches; size of separator pulley, 3 inches; size of large pulley on intermediate, 18 inches; size of small pulley on intermediate, 5 inches; speed of shaft, 180 revolutions per minute. The known conditions given here are indicated in the diagram above by figures, the unknown by x (Fig. 54). The calculation in this problem begins at the separator, where both the speed and diameter of the pulley are known, and ends with the determination of the speed of the engine. 1. Determine the speed of the intermediate which has a large pulley at one end and a small one at the other. Applying the foregoing rules, the speed of intermediate is equal to : 6000x3-4-18 = 1000 rev. per min. 2. Determine diameter of pulley on main shaft. This is equal to: 1000x5-f-180=27.7 inches. 3. Determine speed of drive pulley on engine. This is equal to: 180X27.7^16=312 rev. per min. With most engines a great range of speed is possible by regulating the governor. It is better, however, to have the drive pulley of such size as to keep the speed under 300 revolutions per minute. CREAMERY BUTTER MAKING 191 FRICTION : ITS ADVANTAGE AND DISADVANTAGE. The resistance produced by one body sliding over another is called friction. No matter how smooth a sur- face may appear it always contains irregularities (molec- ular) which are not imlike the teeth of a saw, though so small as to render them invisible to the naked eye. When- ever, then, two surfaces are put together they inter- lock and when made to slide over each other produce friction. Friction as Applied to Belts. Practical application of friction is made in transmitting power by means of belts. Without friction such transmission would be im- possible. The highest efficiency of belts is obtained where there is no slipping or stretching, conditions made possi- ble by observing the following points : 1. Use only good leather belting. 2. Avoid too slack or too tight belts. 3. Run belts with the hair side next to the pulley. 4. Cover face of pulley with belting and have . the hair side out. 5. Keep belts dry and flexible. Size of Belting. A two-ply belt may be subjected to an effective tension of 40 pounds per inch of width with- out straining it. In determining, therefore, the width of a belt for a given horse power the effective tension of the belt must be considered. Further, since a fast running belt is capable of transmitting a greater horse power per given width than a slow running belt, the speed of the belt must also be considered. Hence the following formula : 192 CREAMERY BUTTER MAKING M^rA.^ f K u No. H. P. X 33,000 Wiath of belt= — ^p^^ ^^^ 77. TT D X No. rev. X 40 In which H. P. = Horse power. 33,000 = Number of foot-pounds in one H. P. No. rev. = Number of revolutions of drive pulley per minute. 40 = Effective tension. TT = 3.1416. D. = Diameter of drive pulley in feet. Example : What width of two-ply belting is required with a drive pulley fourteen inches in diameter, making three hundred revolutions per minute and developing ten horse power? Applying our formula we have : 10 X 33,000 „^. , "^'^''^ = 3.1416X14X300X40 = '"^ ^"^^^^- Lacing Belts. In lacing belts care must be taken never to cross the lacing on the side of belt next to the pulley, nor to have more than a double thickness of lacing. The ends of the belt should be cut off squarely so as to have them come together at all points. Holes are punched in a line one inch from the cut edges with the outer ones within half an inch of the edge of the belt. They should be just large enough to permit double lacing. The lacing is best begun at the middle of the belt, care being taken to have the smooth side of the lace on the side of the belt that runs on the pulley. The ends are fastened either by running them through small holes punched in line with the lace holes, or by cutting a small slit in the middle of one end, then cutting into the edge and toward the end of the other, which is run through the slit just beyond the cut edge. CREAMERY BUTTER MAKING- 193 Rubber belts are not as desirable for creamery use as leather belts. Adjustment of Shafts. To avoid straining a belt the shafts must be parallel. This means that where the inter- mediate and engine are hitched to the same shaft the latter must be placed in position first. The engine and intermediate are then lined up so as to have their shafts run parallel with the main shaft. When the shafts are parallel the pulleys are easily adjusted so as to have the belts run on the middle of the pulley. Lubricants or Oils. These slippery substances act in a two- fold way in minimizing the friction between sliding surfaces : ( i ) by filling up the inequalities of the sliding surfaces, thus preventing interlocking; (2) by allowing oil to slide on oil instead of one solid surface upon another. The best oils are those that are entirely free from any tendency to gumminess and it is economy to use only such. Indeed in fast running machinery no other oils are permissible. Consistency of Oils. This is determined by the use to which the oil is put. In fast running machinery where there is little pressure on the bearings, as, for example in a cream separator, very thin oil is most serviceable. The reasons for this are ( i ) that only a very thin layer of oil is required in the bearings of such machinery, and (2) that there is some friction produced in one layer of oil sliding upon another, and the thinner the oil the less will be the friction produced in this way. The crank shaft of an engine, which runs at a com- paratively low speed and is subjected to more or less pressure, requires a rather heavy oil for best service. Hot Bearings. These are most frequently caused by 194 CREAMERY BUTTER MAKING using an insufficient amount, or the wrong kind, of oil. Hot bearings are also frequently caused by dirt, slipping belts, too tight belts, and too tight bearings. TOOLS, PACKING, AND STEAM FITTINGS. A creamery contains a great deal of machinery and Fig. 55.— Pipe cutter. Fig. 56.— Stock and die piping. The need of an ample supply of tools, packing, and steam fittings is therefore evident. Tools. These consist mainly of pipe cutter, two pipe tongs, vise, stock and dies, alligator wrench, a pair of gas pliers, hammer, punch, and screw driver. Fig. 55 shows pipe cutter ; Fig. 56, stock and dies ; Fig. 57, alligator wrench ; Fig. 58, vise ; and Fig. 59, pipe wrench. CREAMERY BUTTER MAKING 195 Packing. All steam stuffing boxes should be packed with asbestos which has been treated with a mixture of oil and graphite. Fig. 57.— Adjustable alligator wrench. Pipe joints, such as unions, should be fitted with rainbow gas- kets to which a little graphite or chalk is added to prevent their sticking to the joints. Pipes that must be frequently taken apart should have ground joints. These will do away with the use of gaskets which are troublesome in such cases. Steam Fittings. Extra fittings for one-half to two inch pipes should always be on hand. The necessary fittings are elbows, nip- ples, bushings, tees (Ts), plugs. Fig. 58 -vise. lock nuts, couplings, reducing couplings, and unions. Fig. 59.~Pipe wrench. 196 CREAMERY BUTTER MAKING When using right and left nipples, that is, nipples with a right thread at one end and left thread at the other, screw each end separately into the pipe which it is to fit and count the number of threads covered. If, for exam- ple, four right threads are covered and six left threads, then cover two left threads be- r" \ fore joining with the other ^^ — -^ • ^ end. In this way the two ends turn tight at the same time, which is necessary to prevent leaking. VALVES. The subject of valves is an important one and deserves much attention. Usually the ordinary creamery contains from twenty-five to fifty valves. It is, therefore, not sur- prising to find steam and water leaks in a creamery building. To replace a valve as soon as it begins leaking is too expensive. The proper thing to do is to repair it. In the following paragraphs a brief discussion will be given of the kinds of valves and the methods of repairing them. Globe Valve. This valve, shown in Fig. 60, takes its name from its globular form. It is preferably so placed as to allow the pressure of the steam to come under the valve. Check Valve. This is placed between the boiler and the feed pipe to prevent the return of water and steam. Fig. 60.— Globe valve. CREAMERY BUTTER MAKING 197- Gate Valve. As its name implies, this is a valve closed by a gate. Throttle Valve. This is the valve that admits the steam to the engine. Stop or Gas Valve. This is opened by giving it a half turn. It is commonly used on receiving vats, and on milk and skim-milk pipes. Rotary Valve. This is illustrated by the stop cocks used on the boiler. Ball Valve. This is an automatic valve ^'Uustrated by the float that regulates the feed of the separator. Parts of a Globe Valve. These are: (i) chamber; (2) seat; (3) stem; (4) stuffing box; (5) disc; and (6) handle. The chamber is the place where the valve oper- ates. The disc is attached to the stem and closes the valve by turning it onto the seat. Repairing of Globe Valves. There are three parts in a valve that may cause it to leak : ( i ) the seat, (2) the disc, and (3) the stem. In valves like the Huxley where the seat and disc are replaceable, extras should always be kept on hand so that either may be replaced when leaking. In valves like the Jenkins where only the disc is replace- able a "reseater" should be at hand whereby the seat of the valve can be made to fit tight again. A reseater for valves from one-half to one and one-half inches in diameter can be bought for twenty-five dollars, and creameries that use valves in which the seat is not re- movable should be provided with one. The valve discs are made of various materials, but, for ordinary steam pressure, brass and * 'composition" discs are giving the best satisfaction. 198 CREAMERY BUTTER MAKING The stuffing box of the valve is packed with asbestos to which a mixture of oil and graphite is first added. This packing will prevent the stem from leaking. The burr of the stuffing box must be tightened from time to time when it shows signs of leaking. Fig. 61.— Intersecting planes. Pig. 62.— An aid to lining up shafts. In case of water valves the stuffing boxes are best packed with oiled candle wicking. LINING UP SHAFTING. Fasten a heavily chalked string along the ceiling paral- lel to the direction the shafting is to take. Snap the string, and a white mark will indicate the position of the CREAMERY BUTTER MAKING 199 shafting in a plane at right angles to the floor. This plane is indicated by the line ab in Fig. 6i. Next determine the position of the shafting in a plane parallel to the floor, indicated by the line cd. This is done as follows : Loosely fasten the hangers along the white chalk line and properly fasten the shafting. Now hang on the shafting, at intervals of three feet, pieces of board like that shown in Fig. 62. The upper end is rounded to fit over the shaft, while the lower end is perforated as indicated by the dot. These pieces of board must be carefully cut so that the distance P is the same in all. If the holes at the lower ends are all in line the shafting is properly lined up. If not. the shaft needs readjusting. CHAPTER XVir PASTEURIZATION AS APPLIED TO BUTTER MAKING. The process known as pasteurization derives its name from the eminent French bacteriologist Pasteur. It con- sists in heating and cooHng in a manner which will de- stroy the vegetative or actively growing bacteria. Milk or cream is also considered pasteurized when only the bulk of the vegetative bacteria is destroyed. Beginning of Cream Pasteurization. About fourteen years ago Storch, the noted Danish scientist, succeeded in isolating from milk the bacteria that are needed in successfully ripening cream. Cultures of these bacteria were prepared and propagated in his laboratory and placed upon the market for cream ripening. It became evident to Storch, however, that the best results could not be expected when these cultures were added to cream that was already teeming with various species of bacteria. This led him to the idea of preparing a clean field for his cultures by destroying the germs that already existed in the cream by pasteurizing it. After this treatment the cream was inoculated with the desirable germs that he had isolated and propagated for this purpose. The result of this practice was that it became possible to produce butter which not only possessed a very fine flavor but which was characterized by its extreme uniformity and good keeping quality. Storch soon succeeded in introducing this method of butter making into Danish creameries which has done 200 CREAMERY BUTTER MAKING 201 much toward making Denmark the most noted butter- producing country in the world. Practically all butter produced in that country at the present time is made from pasteurized cream. Pasteurized Butter in America. The growth of the system of pasteurized butter making has been slow in America up to within recent years. That pasteurized butter possesses merits over unpasteurized has, however, long since been demonstrated by American agricultural colleges and private investigators. It remained, never- theless, for our practical butter makers to place the merits of this system beyond a possible doubt. During the past two years most of the important prizes awarded to butter makers have gone to makers of pasteurized butter. M. Sondergaard and John Sollie, two cham- pion butter makers of the United States, are the firmest advocates of pasteurization. Creameries all over the country are now turning their attention to pasteuriza- tion and the general adoption of the system in America can only be a matter of time. The Continental Creamery Co. of Topeka, Kansas, one of the largest creameries in the w^orld, is now making butter exclusively from pas- teurized cream. Why We Should Pasteurize. It must not be for- gotten that the standard of American butter is becom- ing higher year after year. Methods which only six years ago produced a butter that, fairly suited the general market, are now obsolete and unsatisfactory. In il- lustration of this may be cited the practice of using butter- milk starters, or the use of no starters at all, in creamery practice. The author has closely watched the careers of several young men who, only a few years ago, had met with a fair degree of success in ripening cream with but- 202 CREAMERY BUTTER MAKING termilk starters, but whose persistence in adhering to old methods has driven them out of the profession of butter making. The rational use of starters has done much to raise the genei^al standard of butter in America. But the finest starters added to cream already teeming with many species of good and bad bacteria, can not produce the best re- sults. It is obvious that the best results with good starters are possible only when the bacteria in the cream are first destroyed by pasteurization so that the good germs intro- duced by the starter may have a clean field for develop- ment. If nothing but clean, uncontaminated milk were de- livered at our creameries, pasteurization could hold no place in our system of butter making, for such milk could not be improved by this process. But we can not hope, for many years at least, to have all milk arrive at the creameries in good, clean condition, though of course great possibilities remain for improvement in this direction. Some milk will persist in coming to the cream- ery too good to reject and too poor to make the best qual- ity of butter. Then, too, with the advent of the hand separator system in creamery butter making, pasteurization has become more imperative than ever before. Where cream of vary- ing ages and acidity is received it is more difficult to secure uniformity and good keeping quality in butter than is the case where the milk is daily delivered to the cream- ery. It is hoped that the general recognition of the merits of pasteurization will soon be followed by the adoption of this method of butter making in all of our creameries. We need to produce a butter of better keeping quality and CREAMERY BUTTER MAKING 203 of greater uniformity, two qualities which American but- ter notably lacks. Some of the advantages of pasteurization are well set forth by M. Mortenson in an article contributed to the Chicago Dairy Produce (p. 798, 1903). He says: "By pasteurizing the cream and adding a starter he (butter maker) secures perfect control of fermentations, and he will be enabled to make a uniform grade of butter. By pasteurization it is also possible to remove taints caused by foods consumed by the animal, also taints that have been absorbed by the milk from unfavorable surround- ings. One point strongly in favor of this system is the keeping quality which pasteurized butter possesses. If we desire to compete for the foreign trade we must make pasteurized butter. A dealer in Montreal informed me that he would willingly pay one cent more for pasteurized than raw cream butter." Mortenson is one of our most successful butter makers and a champion of pasteuriza- tion. Methods of Making Pasteurized Butter. Pasteur- ized butter may be made by pasteurizing either the milk or the cream. The latter method is the one generally em- ployed at the present time. The machines used for pasteurizing are of two kinds : I. Discontinuous pasteurizers, used for pasteurizing small quantities of milk or cream, in which the heating lasts from 15 minutes to i hour, according as the tempera- ture is high or low. 2. Continuous pasteurizers in which a constant stream of cream or milk flows through the machine and is heated only during its few moments pas- sage from the bottom to the top of the pasteurizer. The heating in both classes of machines is done in a jacket surrounding the milk or cream in which either 204- CREAMERY BUTTER MAKING live steam or hot water is used. The latter is to be preferred, because hot water does not scorch as much as live steam. Fig. 63. -Cream pasteurizer and cooler. In purchasing a pasteurizer the following points should be observed : first, the ease with which the machine can be cleaned; second, the capacity, which should be large enough to avoid crowding ; third, the ease and uniformity with which the cream or milk can be heated ; fourth, the durability of the machine. It is a great mistake to buy a machine of too small CREAMERY BUTTER MAKING 2Ud capacity. Such a machine must be fed so heavily as to necessitate a thick layer of milk or cream over the heating surface which can not result in uniform heating. DISCHARGL SPRING WATER SUPPLY ice: water RETURN ICE WATF.R SUPPLY Fig. 64.— Cream cooler. Cream Pasteurization. For creameries the most popu- lar as well as the most practical method of making pas- teurized butter consists in heating cream to 185° F. in a continuous pasteurizer and then rapidly cooling it to 65° F. By this treatment the great bulk of bacteria is de- stroyed. Fig. 63 illustrates a common form of pasteurizer and cream cooler. The cream flows directly from the separa- tor into the bottom of the pasteurizer whence it is forced upward by means of revolving dashers, which finally discharge it over the cream cooler at the left. 206 CREAMERY BUTTER MAKING The circulation of the water in the cooler is indicated by the arrows. A cooler consisting of 12 discs will cool the cream from two separators to within 10 degrees of the temperature of the water. It will be noticed from the cut that the cooler is pro- vided with a cover, but it is best to leave this off as pas- teurized cream needs very thorough aeration. A cooler like that shown in Fig. 22 will cool and aerate cream satisfactorily when made large enough. It should be at least 10 feet long and i foot wide. Fig. 64 illus- trates another form of cream cooler which has proved very efficient. Pasteurization will not prove successful unless the cream is rapidly cooled to at least 65° F. immediately after it leaves the pasteurizer. During the past four years a great many experiments have been carried out at the Michigan Dairy School along pasteurizing lines, with a view of determining the advantages of making pasteurized butter. The experiments have had for their immediate objects: I. To study the relative merits of pasteurizing whole milk and cream ; 2. To study the extent to which pasteuriza- tion improves the quality of the butter; 3. To study the keeping quality of pasteurized butter. The results of these tests are briefly summarized as fol- lows : 1. There was practically no difference in the quality of the butter produced from pasteurized whole milk and that made from pasteurized cream. 2. Where the milk was of average purity the butter from the pasteurized cream scored on an average 3 points higher than that from the unpasteurized, using, 15% starter in each case. CREAMERY BUTTER MAKING 207 3. When the milk was below average purity, the but- ter from the pasteurized cream scored from 4 to 6 points higher than that from the unpasteurized, using 15% starter in each case. 4. When the unpasteurized cream from milk below average purity was ripened without starter and the pas- teurized cream from the same milk was ripened with 15% starter, the difference in the scores was from 8 to 1 1 points in favor of the pasteurized cream. 5. The keeping quality of the butter made from pas- teurized cream was in most cases so far superior to that from the unpasteurized, that the author feels that the in- creased keeping quality alone should warrant the general introduction of pasteurization in our system of butter making. Samples of the butter obtained in the above experiments were usually sent to W. H. Healey, New York City, for scoring. A host of other careful experiments conducted in Wis- consin, Iowa, Canada, and elsewhere, have so firmly estab- lished the merits of pasteurized butter that the general in- troduction of the system of pasteurization can not long be delayed. Purification of Wash Water. The matter of using clean, pure water for washing butter has hitherto not received the attention which this subject demands. There is no question that much butter is robbed of its rich, creamy flavor by too much w^ashing with impure water. Experiments conducted at the Iowa station and elsewhere have shown that the flavor and keeping quality of butter can be improved by purifying the average wash water, either by filtering or sterilizing it. Where pasteurized butter is made it is of the utmost 208 CREAMERY BUTTER MAKING importance to use nothing but pure water for rinsing cream vats and washing butter, else pasteurization will prove a delusion. Purifying Water by Filtration. Most people are familiar with the purifying action which water under- goes in its passage through sand, gravel, charcoal, etc. For purifying water used for washmg butter, artificial filter beds constructed of such material have given excel- lent satisfaction. The filter can described in bulletin No. 71 from the Iowa Experiment Station is 48 inches high, 18 inches in diameter, and constructed of 22 gage galvanized iron. Be- ginning at the bottom the filtering material was placed in the can in the following order: i. 2 inches of small flint stones ; 2. 22 inches of fine sand ; 3. 12 inches of fine coke ; 4. 9 inches of charcoal ; 5. 2 inches of fine stone or coarse gravel. Two perforated plates are placed in the can, one near the bottom upon which the filtering material rests, the other on top of the fine sand. A third and concave plate is placed near the top with a hole in the center, which directs the water to the center of the filter bed. This can has a filtering capacity of 16 gallons per hour, and it is claimed that the filter does not need to be cleaned or renewed oftener than once in four months and possibly not this often. The cost of the can is $11.11. Filtration offers one of the cheapest methods of purify- ing water and is the method generally employed by cities that are dependent upon lakes for their water supply. Purification of Water by Heating. Water may be pas- teurized in the same manner as cream. There is, how- ever, one objection to this method of purifying water, and that is the bad effect which it has on the pasteurizer. In the course of time a distinct laver of the mineral im- CREAMERY BUTTER MAKING 209 purities of the water will be deposited upon the walls of the pasteurizer in a manner similar to the formation of scale in the boiler. This mineral deposit will in time destroy the usefulness of the pasteurizer. CREIAMEIRV ROOM A STE.RII_IZ.E1D V^ATE-R. BOIUE.R ROOM ri_OOR. Fig. 65.— Showing method of sterilizing wash water for butter. A more satisfactory method of purifying water by heat- ing is illustrated in Fig. 65. The water is pumped from" the well into the galvanized iron tank A, which is placed about 6 feet above the floor in the boiler room. This tank is tightly covered with the exception of a small vent in the cover. The water is heated by placing a series of galvanized iron pipes in the bottom of the tank through which all, or a part, of the exhaust steam from the engine is con- ducted. In this way the expense of heating water will cost nothing more than a slight back pressure on the 210 CREAMERY BUTTER MAKING The hot water may be drawn off from this tank when- ever desirable and cooled in the same manner as the cream, that is, by running it over the cream cooler B. From the cooler the water should be run into a tank, in which it can be cooled to the desired temperature by means of ice water. The water as it leaves the cooler will have a temperature of from 60 to 65 degrees, so that only enough ice will be needed to reduce the tempera- ture about 10 degrees. Fig. 65 also illustrates the method of heating water for the boiler and for general washing. Cost of Pasteurizing Cream. Unfortunately definite data on the cost of pasteurizing cream are still wanting. According to Danish experiments the cost will be approxi- mately .1 cent per pound of butter. These results seem to be confirmed by the best practical butter makers in this country who have pasteurized for several years. The cost of pasteurizing must, however, always depend largely upon the manner in which the pasteurizing pro- cess is carried out. For example, if the water used for cooling the cream is pumped into the water supply tank for the boiler, a large portion of the heat used for pas- teurizing is recovered. Further, if the proper coolers are used, ordinary well water will cool the cream to the ripening temperature without the use of ice. Some have also found it practical to use the exhaust steam from the engine for pasteurizing cream. The care and cleaning of the pasteurizer and cooler will, of course, entail extra labor, but the labor thus in- volved will not materially add to the expense of pasteuriz- ing. Pasteurization of Gathered Cream. There is proba- bly no problem along pasteurizing lines of greater impor- CREAMERY BUTTER MAKING 211 tance at present than the pasteurization of hand separator or gathered cream. Heretofore the apparent difficulty in the way of pasteurizing this cream has been the high degree of acidity which it often reaches before deHvery to the creamery. To arrive at some definite conclusions, a series of ex- periments was carried out at the Michigan Dairy School under the direction of the author, in which cream with an acidity varying from .3 to .6 per cent was pasteurized in a continuous pasteurizer at a temperature of 185° F. After pasteurization, one-half was left without starter, the other half was treated with 25 per cent starter after it had reached a temperature of 65° F. Both lots were then cooled to 48° F., where they were held for ten hours and then churned. Control experiments were car- ried of unpasteurized cream ripened without starter. Samples of the butter made were sent to W. H. Healy of New York for scoring. The results obtained in these experiments are sum- marized as follows : 1. Cream with a fat content of from 20 to 40 per cent can be pasteurized without difficulty even when the acidity reaches .6 per cent. 2. When no starter was added to the pasteurized sour cream no improvement in the flavor of the butter was noticeable. 3. When the pasteurized sour cream was treated with 25 per cent starter the flavor of the butter was improved from 2 to 4 points in every experiment. 4. Pasteurizing sour cream destroys its heavy con- sistency, which cannot be recovered even when ripened with 25 per cent starter. The body of the butter from this cream was perfect, however. 212 CREAMERY BUTTER MAKING 5. There was practically no difference in the yield of butter from the pasteurized and unpasteurized sour cream. 6. The average test of the buttermilk from the pasteur- ized sour cream was .07 per cent, that from the unpasteur- ized, .09 per cent. 7. There was a marked increase in the keeping quality of the butter made from pasteurized sour cream treated with starter. 8. The acidity of the sour cream was somewhat dimin- ished by the pasteurizing process. These experiments have shown that it is absolutely essential to add a heavy starter to the pasteurized sour cream even if the latter shows an acidity of .6 per cent. CHAPTER XVIII. CO-OPERATION. I. Co-operative Creameries. There are two distinct classes of creameries in existence at the present time. ( I ) Those owned and operated by private individuals, called proprietary creameries; (2) those owned and oper- ated by the patrons, known as co-operative creameries. Most of the creameries built at the present time belong to the co-operative type. This is the ideal plan upon which creameries should be built and operated and it has in most cases proved successful. Methods of Organizing Co=operative Creameries. Too frequently co-operative creameries are established by so-called "promoters," whose aim is to make money for themselves by taxing the farmers a thousand dollars or more in excess of the actual cost of the creamery. If a community of farmers is interested in the estab- lishment of a creamery, the following method of organiz- ing should be pursued : 1. Let those most interested in the project make a thorough canvass of the milk producers in that community to ascertain the number of cows available. There should not be less than 400 cows to start with. 2. If the desired number of cows is available, the next step is to secure a subscription of $4,500 by selling shares for that amount. This sum of money is necessary to build and equip a substantial fire proof creamery containing all the modern creamery machinery. Where possible it is 213 214 CREAMERY BUTTER MAKING desirable to sell shares only to prospective creamery patrons, so that the creamery may be a truly co-operative one. 3. When the necessary funds have been subscribed, call a meeting of the shareholders to elect a president, secretary, treasurer, manager, and a board of directors which should consist of the president, secretary, treasurer, and at least three other shareholders. 4. The next step is to specify a certain time within which all subscriptions must be paid. The money is pref- erably turned over to a reliable banker in the form of notes bearing interest. 5. The treasurer should be authorized to draw upon the bank for the money thus deposited whenever occasion demands, but he should be required to give security for the money that comes into his hands. 6. When all subscriptions have been paid, a meeting of the board of directors should be called for the purpose of hiring a butter maker who shall not only be able to make a first class article of butter, but who shall also be competent to plan and superintend the construction of the creamery. This is a point w^hich most co-operative cream- eries overlook. The result is there are dozens of cream- eries scattered all over the country which are faulty in both design and construction. Before drawing up his plans it would be policy for the butter maker to visit several up-to-date creameries so as to get the latest ideas on creamery construction. 7. The creamery is paid for out of a sinking fund created by charging the patrons, in addition to the charge necessary to cover running expenses, say one cent for every pound of butter fat delivered until the creamery is paid for. CREAMERY BUTTER MAKING 215 8. After the creamery is paid for, there should l)e an annual dividend declared to the shareholders as inter- est on their investment. 9. A sufficient sinking fund must be maintained to cover the annual dividend and the running expenses, by charging from two to three cents for every pound of butter fat delivered. Management of Co=operative Creameries. Too fre- quently the management of co-operative creameries is placed in the hands of persons who know little or nothing about creamery matters. Perhaps more co-operative creamery failures can be traced to this cause than to any other. The stockholders of co-operative creameries should select a manager and managing board who are familiar with the details of the business they are going to manage. Advice should freely be sought from the butter maker who in most cases is the best posted man to govern the affairs of the creamery. 2. Co=operation of Butter maker and Patron. The relationship of butter maker and patron should be one of mutual interest — a business relationship. Butter making is a business and, as such, should be governed by business principles. The butter maker, then, besides being able to make a fine quality of butter, must be a business man, dealing as he does with farmers, bankers, merchants, mechanics, and others. He must be honest, tactful, and full of enterprise. Too frequently self-interest figures too conspicuously in the management of creamery affairs. This can not help but result, sooner or later, in the ruination of the business. The butter maker has, and must have, certain rights which, if rightly asserted, can not help but be productive 216 CREAMERY BUTTER MAKING of much good. If used otherwise, these rights will create enmity and become a damage to the creamery. For exam- ple, a butter maker has a right to demand of his patrons good clean milk, but he can not attain his object by repeatedly sending back milk that is not right. Tactfully explaining the evils resulting from unclean milk, giving the probable cause, and manifesting a willingness to visit his premises, will accomplish very much more in reform- ing the patron. Greeting the patrons with a smile and a ''good morn- ing" inspires confidence. Accuracy in sampling, weighing and testing, a clean person and clean surroundings, are things that merit more than ordinary attention. The best way for butter makers to get along with their patrons is to help them in every way they can. They should act as educators of their patrons in their respective communities. No person has a greater opportunity for doing good in his community than the butter maker. A few printed instructions to patrons occasionally can not fail to be productive of much good, both to the patron and to the butter maker. The following may be con- sidered as sample instructions : 1. Get cows that are purely dairy animals. Cows that have a tendency to lay on flesh while giving milk are not the most profitable for the dairy. A milch cow should convert her food into milk, not into flesh. Such a cow you will generally find a spare, lean looking animal. 2. Do not be afraid to invest $ioo in a good sire of some good dairy breed to head your herd. See to it that this sire is a descendant of prolific milkers, and that he has good breeding qualities. 3. Feed liberally. Remember that about sixty per cent of what a cow can eat and properly assimilate is CREAMERY BUTTER MAKING 217 required for her maintenance ; that which is fed beyond this is utiHzed for the production of milk if the cow is a purely milk-producing animal. Hence the wisdom of feeding a cow to her full capacity. 4. Do not feed just one kind of feed. Variety of feeds is essential in economical feeding. 5. Feed liberally of concentrated feeds like bran and oil meal, especially during scarcity of pasturage. 6. Do not be afraid to invest $16 in a ton of bran, for its value to you as a fertilizer alone is $11. 7. Always milk your cows at the same time morning and evening. Regularity in milking means more milk. 8. Do not change milkers, and insist that the milkers treat the cows gently. 9. Always thoroughly cool night's milk by placing it in cold water and stirring it frequently. 10. Do not allow the calves to suckle the cows more than three days after calving. 11. Always add a few tablespoonfuls of oil meal or cooked flax seed to the skim-milk before feeding it to your calves. 12. Grow a liberal supply of clover and peas, for these produce a liberal flow of milk, at the same time enrich- ing the soil. 13. Grow an abundance of corn and ensilo it. It may prove your most economical feed. 14. Never place your milk cans in the barn while milking for the barn odors will taint the milk. 15. Do not bed or feed your cows, or in any way dis- turb the barn dust, while milking. 16. Always provide your cows with a liberal supply of salt and pure water. Never allow them to drink stag- nant water. 218 CREAMERY BUTTER MAKING ly. Bring samples of milk from the individual cows of your herd for testing. It will cost you nothing, but it may be of great value to you. i8. A sample consisting of a portion (i oz.) of the night's and morning's milk is necessary for a test. Always thoroughly mix milk before sampling. CHAPTER XIX. DETECTION OF TAINTED OR IMPURE MILK. In well regulated creameries the head butter maker will usually be found at the intake every morning care- fully examining the milk as it arrives at the factory. It requires skill and training to detect and properly locate the numerous taints to which milk is heir. It also requires considerable tact to reform patrons who have been care- less in the handling of their milk. The best skill available in the creamery should therefore be placed in the intake. In the daily examination of milk, defects can usually be detected by smelling of it as soon as the cover is re- moved from the cans. When, however, milk arrives at the creamery at a temperature of 50° F. or below, it becomes more difficult to detect taints ; indeed during the winter when milk is often received in a partly frozen condition, experts may be unable to detect faults which become quite prominent when the milk is heated to a temperature of 100° F. or above. Frequently milk is seeded with undesirable kinds of bacteria which have not had time to develop sufficiently to manifest themselves at the time the milk is delivered to the creamery, but which later in the course of cream ripening produce undesirable flavors. It is necessary, therefore, in making a thorough examination of milk to heat it to a temperature of from 95° to 100° F. and to keep it there for some time to permit a vigorous bacterial development. Such bacterial development is best carried on in what is known as the Wisconsin Curd Test, a full description of which is given below. 219 220 CREAMERY BUTTER MAKING WISCONSIN CURD TEST. This test originated at the Wisconsin Dairy School. The name of the test impHes that the samples of milk to be tested are curded, which is accomplished in a man- ner similar to that in which milk is curded for cheese making. The Wisconsin Curd Test is frequently spOKen oi as ''fermentation test," since the process involved consists in fermenting the milk by holding it at a temperature at which the bacterial fermentations go on most rapidly. Apparatus. This consists of one pint cylindrical tin cans placed in a tin frame, and of a well insulated box made so that the tin frame will nicely slide into it. Added to this is a case knife, and a small pipette used to measure rennet extract. The construction of the box and the position of the cans inside is illustrated in Fig. 66. This box consists of three-eighths inch lumber, the inside of which is lined with a quarter inch thickness of felt. Narrow strips are tacked on the felt and tin upon these, the object of the strips being to prevent conduction of heat by contact of the tin with the felt. The cover of the box is constructed in the same way and made to fit tight. This construction makes it possible to maintain a nearly constant temperature of the samples which are surrounded by water as shown in the illustration. Making the Test. A curd or fermentation test is made at the creamery by selecting from each patron about two- thirds of a pint of milk and placing this in the tin pint cans after they have been thoroughly sterilized. Each pint can should be provided with a sterilized cover which is placed upon it as soon as the sample has been taken. CREAMERY BUTTER MAKIXG 221 The sample cans are next placed in the insulated box provided for them. Here they are warmed by adding water at a temperature of 103° F. to the box, a tempera- ture which should be maintained throughout the whole test. WOOO rCUT UIMllMG. STRIFES oj:- Fig. 66.— Section through curd test. With a sterile thermometer watch the rise in tempera- ture until it has reached 86° F. when 10 drops of rennet extract are added to each sample and mixed with it for a few moments with a sterile case knife. This knife must be sterilized for each sample to avoid transferring bacteria from one can to another. As soon as the milk has curdled it is sliced with the case knife to permit the separation of the whey. After the whey has been separating for half an hour, the sam- ples should be examined for flavor, which can be told far better at this stage than is possible by smelling of the milk as it arrives at the creamery. After the samples have all been carefully examined, the whey is poured off at intervals of from twenty to forty minutes for not less than eight hours. At the end 222 CREAMERY BUTTER MAKING of this time a mass of curd will be found at the bottom of the can in which there has been a vigorous develop- ment of bacteria throughout the test. If the sample of milk is free from taint, this curd when cut with a knife will be perfectly smooth and close. If, on the other hand, the sample contains gas germs, these in course of eight hours' development will have produced enough gas to give the curd an open spongy appearance when cut. The openings are usually small and round, hence the name ''pin holes" has been applied to them in- dicating holes the size of a pin's head. Whenever, therefore, milk produces a curd that an- swers this description it may be taken for granted that it contains undesirable bacteria. Sometimes the milk may be tainted and yet produce a close textured curd, but in such cases the taint can be detected by carefully smelling of the curd. Precautions. In making a test as above outlined two things must constantly be kept in mind: first, that to se- cure the desired bacterial development, the temperature of the samples must be maintained as nearly as possible at 98° F., which is accomplished by surrounding them with water at a temperature of 103° ; second, that to avoid con- taminating one sample with another, the knife used for mixing the rennet with the milk and cutting the curd must be sterilized for each can. The thermometer used must also be sterile. The temperature of the samples can easily be main- tained by using a well insulated box like that shown in Fig. 66. When a common tin box is used it becomes necessary to change the water in it about once every half hour. CHAPTER XX. CARE OF MILK AND SKIM-MILK. No matter how skillful a butter maker may be he can not produce the highest quality of butter from milk of inferior quality. Skill may do much to improve qual- ity but it can never make perfection out of imperfec- tion. It should, therefore, be as much a duty of the butter maker to keep his patrons properly instructed in the care and handling of milk as it is to keep himself posted on the latest and most approved methods of making butter. The cows should be milk- ed in clean, well ventilated barns in which the air is kept free from dust during milk- ing. This means that cows should not be fed or bedded about milking time. In ordinary milking a great share of the bacteria find their way into the milk through the dust that dislodges from the animal. This is easily prevented by wiping the flanks and udder of the cow with a moist cloth just before milking. Immediately after the milk is drawn it should be re- moved from the barn to a clean, pure atmosphere where it is aerated and cooled by running it over a combined aerator and cooler like that shown in Fig. (yj. The 223 Fig. 67.— Milk aerator and cooler. 224 CREAMERY BUTTER MAKING barrel here shown is fihecl with cold water which circu- lates, as it flows from the barrel, between the two tin surfaces of the cooler over which the milk flows in thin sheets, thus cooling it to within five degrees of the tem- perature of the water. Fig. 68. -Skim-milk pasteurizer. The ordinary method of cooling milk in ten gallon cans by setting them in a tank of cold water is too slow. The result is that during the summer months milk frequently arrives at the creamery sour or nearly so. All milk should be strained through absorbent cotton. A strainer consisting of a few thicknesses of cheese cloth is of little value. Milking utensils, such as pails, cans and dippers, should be thoroughly washed and scalded after which they are placed in direct sunlight. Pasteurization of Skim=milk. To secure the greatest feeding value of skim-milk it must be fed sweet. During the summer months skim-milk as it is ordinarily returned from creameries, keeps sweet but a short time, a fact which has compelled many a farmer to purchase a hand separator and separate the milk at the farm. CREAMERY BUTTER MAKING 225 To keep the skim-milk in good feeding condition it must be pasteurized at the creamery. The cheapest and most common means by which this is done is to heat it with a heater Hke that shown in Fig. 68. This heater utiHzes the exhaust steam from the engine and heats the skim-milk to temperatures ranging from 170° to 200° F. The skim-milk enters at one end of the heater while the steam (either live or exhaust) enters through the top near the point at which the skim-milk enters. The steam thus comes in direct contact with the skim-milk and condenses, heating it to the above tempera- ture. One end of the pasteurizer is removable so as to permit thorough cleaning. Objections have frequently been raised against this method of pasteurizing because of the small quantity of cylinder oil contained in the exhaust steam. Where judg- ment is used in oiling cylinders no trouble need be anticipated from this source as the oil can be detected only with difficulty. Extensive inquiry into the matter of pasteurizing skim- milk has developed the fact that the patrons and the calves must be educated to the change from unpasteurized to pasteurized skim-milk, and where this has been done pasteurization has given the best of satisfaction — indeed the patrons would refuse to accept the skim-milk unpas- teurized. Calves will object somewhat at first to a change from unpasteurized to pasteurized skim-milk (especially if the latter is fed at a temperature of 150° F.) but they will soon begin to like it. A difficulty that has always been experienced in pasteur- izing skim-milk is the foam that results from the heating. Various so-called "foam killers" have been placed upon 226 CREAMERY BUTTER MAKING the market which have been more or less successful in obviating this trouble. Fig. 69 illustrates a method of handling skim-milk which prevents, to a great extent the difficulty usually ex- perienced from foam. EXHAUST STEAM PASTELURIZtR SKIM CAF>Aci-r V MILK ~r/\rsjK 10.000 LBS. skim milk we:igme:r. o SKIM MILK PUMP Fig. 69.— Skim-milk tank and pasteurizer. The pasteurizer is placed on top of the skim-milk tank and the pasteurized skim-milk flows through a pipe which runs to wathin an inch or an inch and a half of the bottom of the tank. A pipe so placed will tend to destroy a por- tion of the foam formed in the heater. The tank is of ample size to hold the foam not thus destroyed, which, during the early summer, is quite considerable. The larger the tank the less trouble will be experienced from the foam. CHAPTER XXL HANDLING AND TESTING CREAM. The rapid introduction of hand separators among^ creamery patrons during the past few years has con- fronted many creamery operators with the problem of how this cream should be handled to make the best quality oi butter from it. The practice of receiving cream instead of milk at the creamery is growing. Creameries which only a few years since were running entirely on the whole milk plan have now changed more or less to cream gather- ing plants. Indeed many creameries that are now being built operate entirely on the hand separator plan. Sampling. Where the cream is delivered to the cream- ery in a sweet condition, composite samples may be taken in the same manner as with milk. Usually, however,, where a great deal of hand separator cream is handled^ some of it is delivered too sour for composite samplings In this case it becomes necessary to test the cream as ofter^ as it is delivered. Where cream of varying degrees of acidity is received,, the following method of sampling and weighing is recom- mended : With a long-handled conical dipper thoroughly mix the cream in the can and then pour into a small glass tube enough of it for a duplicate test. Weigh the cream in the cans in which it is delivered and subtract from the gross weight the weight of the can which should be marked upon it in plain figures. The cream is now^ emptied into one or two receiving vats, one provided for 228 CREAMERY BUTTER MAKING sweet cream, the other for that which has more or less soured. After all the cream has been sampled and weighed, the tubes containing the samples for testing are placed in a water bath at a temperature of 120° where the cream is warmed preparatory to testing. A suitable rack, made to fit the water bath, should be provided for the cream tubes. When the cream has become sufficiently warmed in the tubes, it is poured and repoured a few times and a sample weighed out by transferring the cream to the test bottle by means of an automatic pipette like that shown in Fig. 70. This consists essentially of a pipette with a rubber bulb at one end by means of which the cream is sucked into the pipette and again forced out of it. This method of forcing permits a rapid delivery of the cream. Testing. 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 : Weight of fresh separator cream delivered by a 17.6 c.c. pipette. Per cent of fat Specific gravity Weig-ht of cream in cream. (weighed). in grams. 10 1.023 17.9 15 1.012 17.7 20 1.008 17.3 25 1.002 17.2 30 .996 17.0 35 .980 16.4 40 .966 16.3 45 .950 16.2 50 .947 15.8 CREAMERY BUTTER MAKING 229 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 balance (Fig. 7.), the amount necessary for a full sample being eighteen grams. To save time in weighing place a cream bottle on each side of the scales and balance. Then place an eighteen-gram weight on one side and pour cream into the bottle on the other side until the scales balance. Now re- move the weight and pour cream into the empty bottle until the scales again bal- ance. The same operation is repeated with the next two bottles, and so on. Special Cream Bottles and Tester. Since most cream tests above 30%, a full sample of it can not be tested in a 30% bottle. Fig. 71 illustrates a cream tester which is specially designed to whirl a long-necked cream bottle graduated at 55%. At the left in the figure is shown one of these bottles. Another cream bot- tle graduated to 55% is shown in Fig. 72. These bottles have the advantage of permitting the use of a full sample for testing which insures a more accurate reading than is possible where only half a sample of cream is taken for a test. With proper care, however, cream may be tested in an ordinary tester by using the 30% cream bottler When these bottles are used only half a sample (8 grams) of cream is weighed out and a corresponding amount of acid used. Amount of Acid. It is evident that the richer the Fig. 70.— Auto- matic pipette. 230 CREAMERY BUTTER MAKING ^ream the less the amount of acid necessary for a test, tor acid does not act upon the fat but spends its energy upon Fig. 71. -Cream tester. the serum, which becomes less the richer the cream. 14 or 15 c.c, of acid is usually sufficient for 18 grams of ordinary cream. In case 18 grams of cream are divided between two 30% bottles and the same quantity of water is added, the full measure of acid may be used with satisfactory results. It must be remembered that when only half a sample of cream is used for a test the fat in the neck must always be multiplied by 2 to get the correct reading. Necessity of Grading Cream. It is a fact which can not be disputed that in most of the gathered cream factories some cream is received sweet and some more CREAMERY BUTTER MAKING 231 or less sour. Hence the necessity of grading. The sour cream should be placed in a class by itself and the same with the sweet cream. The butter maker has far better con- trol over sweet cream than he has over sour and can therefore make a better quality of butter from it. It is, then, no more than just that the patron who takes good care of his cream and endeavors to deliver it often, should receive more for it than the man who is careless and de- livers the cream only once a week. In- deed grading cream seems to be the only resource left to the butter maker to in- duce his patrons to deliver sweet cream. W^iere it is desired to churn all the cream in the same churning, a better quality of butter is possible when the sweet cream is ripened by itself with a heavy starter and the sour cream added to this some hours previous to churning. Adding sour cream to sweet cream is equivalent to add- ing so much starter of a kind not likely to produce very good results. Moreover when a fine flavored starter is added to such a mixture its influence is small compared with what it is when added to sweet cream, because acid is a hindrance to the development of the lactic acid bacteria. Necessity of Pasteurizing. Experiments have abun- dantly proven that average cream, whether sweet or sour, will make a better quality of butter when pasteurized. This subject is fully discussed in the chapter on pasteur- ization. Fig. 72.-55% Cream bottle. CHAPTER XXII. 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; (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. 232 CREAMERY BUTTER MAKING 233 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 212° 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 234 CREAMERY BUTTER MAKING 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 CREAMERY BUTTER MAKING 235 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 : Percentag-e of salt by weig-ht. 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 26.6 23.9 21.2 18.7 16.0 12.2 6.1 0.5 -1.1 .992 2 .. .9^4 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 oft' by one ton of ice at 32° F. 236 CREAMERY BUTTER MAKING 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 54 -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. Ihe 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- CREAMERY BUTTER MAKIXG J.6i 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 c}linder, opening it when the fresh cylinder is connected up. "From sixty to seventy-five per cent of the full charge is 238 CREAMERY BUTTER MAKING sufficient to start with so that the air may have an oppor- tunity of escaping with as Httle 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 CREAMERY BUTTER MAKING 239 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 efifect 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 chargirf^ 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. 240 CREAMERY BUTTER MAKING "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 XXIII. creame:ry book-kee;ping. The object of book-keeping is to keep a record of busi- ness transactions, enabling the proprietor or proprietors at any time to determine the true condition of the business. In most businesses usually one of two forms of book- keeping is followed : either double entry which makes use of three books — day book, journal, and ledger — or single entry which makes use of only two books, a day book or journal, and ledger. The day book contains a detailed record of business transactions. Entries are made in this book as soon as the transaction occurs.. The journal contains the debits and credits arranged in convenient form for transferring to the ledger. The ledger contains the final results. Debits and Credits. These words are usually abbre- viated Dr. and Cr. respectively. The debits and credits in any business transaction are determined by the following rule: debit whatez'er costs value; credit zi'hatever pro- duces value. In a journal entry the sum of the debits and the sum of the credits must be equal. Double and Single Entry Book=keeping. While double entry is the most complete form of keeping a busi- ness record, it entails too much work for creameries, which have but a limited time to devote to keeping books. Single entry book-keeping when properly carried out has proved very satisfactory and most creameries follow this method in a more or less modified form. 241 242 CREAMERY BUTTER MAKING In the following pages a simple and approved method of book-keeping is presented which may be followed by any creamery whether proprietary, co-operative, or otherwise. In this method the following books and papers are made use of: (i) Day book, (2) order book, (3) sales book, (4) cash book, (5) pay roll register, (6) ledger, (7) milk sheet, (8) milk book, (9) test book, and (10) butter slips. Day Book. All transactions made at the creamery should be at once recorded in the day book. At the close of the day or at some convenient time the records made in the day book are transferred to the order book, sales book, or cash book, according to the transaction. The following examples illustrate the manner of making records in the day book. January 6, 1900. Sold to J. D. Steele & Co. on account 1 100 lbs. of butter @ 24c $20 8 4 00 50 00 $264 32 33 00 Bought of Newman & Co., for cash, 1 san- itary milk Dumo . . 5 gal. butter color @ $1.70 20 gal. separator oil @ 20c Bought of H. Chandler on account 11 cords of wood (cO $3 00 50 00 When payment is made for goods at the time the transaction occurs the term "for cash" is used. When payment is made some time after the transaction occurs the term "on account" is used. CREAMERY BUTTER MAKING 243 Order and Sales Books. All purchases and sales are recorded in the manner illustrated below : . o o o o o s o o o o o "u O CO O 1— 1 "* cu (M T-H T— t ! €& ;- . 1 o % W( •a •a >— c c c < r (T ^ " ^ h. 2 - § D b o z E ft -s ^ ^ X 'x. 3 u H U U C4 d c U o d o =a s ^ tj U U oa D o>j 0^ 6 3 Q Q C/2 o in crj ^ H eu ^ cii ^ CO t- ^ CD 00 '^od T— 1 tH "<^S "c t. Q'' rt " - - "* ^ 1 8 8 S 8 o •Sp990 -OJa a8N : S •saSa^qo i ^ "5 § 8 8 8 g S i Oh % g g N ji n ^ g o ^ •^qSiOAV § ? g s Jiaqj. --^ - •?qSi8M 8 .? 8 8 ano -- -^ -^ d^ 00 g 8 § ^g >i >^ >^ i ^ z ^ !^ •a O o o o ■a e: >^ c3 < se *: SB s :: 3 m m '4, w xi o o fe O 6 u o cy o 1 ^ «« a ^ Z a a » a c o ii. Ji^ d o ."3 ^ ^ ^ ^ eo o (M |2 OS - - : 244 CREAMERY BUTTER MAKING Cash Book. Cash book records are illustrated below : CASH BOOK Date. Cash received. Mar. 1 " 10 4 " 14 4 " 20 5 " 24 5 •' 24 5 •' 28 5 " 28 5 " 30 5 Balance Butter. . From Feb WiUson&Co Willson&Co Nicholson & Fish. Willson & Son. . . . Nicholson & Fish. Willson & Son.... J. C. R. & Co..... Nicholson & Fish $181 00 180 00 208 00 374 50 249 90 139 80 201 00 10 10 848 38 $2, 392 * Sales book Page, —(monthly record). Date, 1898. Cash paid. Mar. 10 § 6 " 11 6 " 18 7 " 24 7 *' 27 7 ^' 27 7 " 28 7 " 29 7 " 31 7 " 31 7 Butter tubs — Tinning Butter printer. Cleaningpo'der Boiler repair. . . Salary Wood Sundries Patrons Balance Thorbin & Son . . , Paul Burger R. S. D. & Co. . . . R. S. D. & Co.... J. R. Smith & Co John Smith W. Saunders .. . John Jones Monthly dues. .. To new account $90 00 3 00 20 00 11 00 14 00 95 00 55 00 4 35 1,902 48 197 85 $2,392 § Order book page. CREAMERY BUTTER MAKING 245 Pay Roll Register. Each patron's monthly account is recorded in the pay roll register as illustrated below : PAY ROLL REGISTER. Date, 1898. 1 a 1 2 Name. i 6 I 4^ a o a < O 1* April 5 " 5 John Smith PaulWirth 7,850 4,575 3.9 4.0 306.15 183.00 $0 20 20 $61 23 36 60 $1.48 $59 75 36 60 123V 124V V Means paid. The Ledger. Where a good, permanent, and easily accessible record is desirable, the main items of all trans- actions should be posted under suitable heads in the ledger. Where there is liable to be a frequent change of bookkeepers the additional work involved in keeping a ledger is well justified. In case monthly payments are made at the creamery all accounts should be closed once a month and those with different individuals should be kept separate. The fol- lowing illustrates a ledger account with a butter firm in New York. Dr. John Johnson & Co. Cr. 1898. New York City. Sept. 3 " 7 Balance Sale *12 12 13 $90 40 103 38 84 50 Sept. 6 " 18 " 31 Check Check Balance ^14 14 14 $80 35 139 85 " 20 Sale 58 08 Oct. 1 Balance 13 58 08 *Sale s book page. 1 Cash b ook page. 246 CREAMERY BUTTER MAKING Below is illustrated a ledger account with a creamery supply house in Chicago : Dr. J. D. Murray & Co. Or 1898. Chicago. Aug. 4 " 11 Check Check *15 15 15 $29 00 64 50 19 38 Aug. 1 5 " 19 Balance.... Order Order 1il6 16 16 S18 50 70 38 " 31 Balance 24 00 Sept. 1 Balance 16 19 38 *Casl 1 book page. 1 Order book page. The following illustrates a ledger record with a patron of the creamery : Dr. William Sampson. c 'r. 1898. Piketown. August Sept. 31 31 Check Check $61 50 83 92 August Sept. Milk Milk $61 50 83 92 19 *Pay roil register page. Milk Sheet and Milk Book. Immediately after milk- is weighed it is recorded upon a milk sheet placed in the intake. This sheet consists of heavy paper with the date, name, and number of the patron upon it. The names should be arranged in alphabetical order. A suitable milk sheet is illustrated in Fig. y2>- Where care is taken in recording the milk upon the milk sheet, the milk book may be dispensed with. In that case a record of the milk is preserved by filing the milk sheets after each patron's total has been transferred CREAMERY BUTTER MAKING 247 to the pay roll register. In case, however, a careful daily record of the milk is to be preserved, it is better to copy the milk from the milk sheet into a milk book in which a record may be preserved for a long time. '::- r ■" r" *" — - — — ~ '— "" - — — ~ ~ '" ' — f— f— — "i"" ^ ^ ^ - P , „ ^ • n 1, ,, , ,« .7 l