ISM MODERN BUTTER MAKING MARTIN H. MEYER Class _lS^_4S Rnnic !^V^ J Copyright W.. COPYRIGHT DEPOSIT Digitized by the Internet Archive in 2010 with funding from The Library of Congress http://www.archive.org/details/modernbuttermakiOOmeye ■1h- / t/.. / C -c/ix.o i^^-^-^ ^ u " - I .A--^ I^Jpl ' ^^^T^^m±4U^^^Bt fail Hi ^B University of Wisconsin Dairy School, Madison, Wisconsin My acquaintance with over 2000 dairy students in the past 15 years has convinced me that the three months instruction given each year in the winter dairy course of the University of Wisconsin is very helpful to the dairy interests of the state. The buttermakers and the cheesemakers find that an inquiry into the reasons for certain operations in their work helps not only to improve the quality of the products they make, but that by using their minds as well as their muscles the work becomes more interesting. Even a short course in dairying gives many students a start in the right direction and they learn by it to be methodical and systematic in their every day work. They also learn that it is necessary to follow the dairy press and dairy textbooks to keep up with the progress that is made each year. E. H. Farrington. Dairying is the highest and most speciahzed form of agriculture. Its success requires men thoroughly trained along broad and many-sided lines, and skillful in the practical application of their knowledge. The future progress of the dairy industry must, there- fore, largely depend on the number of thoroughly trained and competent dairymen. Men so trained are scarce, their demand far exceeds the supply and their opportunities are as numerous as the pebbles on the beach. The laying of a broad foundation for this life work and the acquiring of this knowledge and training are accomplished most effectively and most rapidly through the medium of our dairy schools. The dairy school is the factory, the clearing house and the distributory of dairy information, and its gra- duates are the pioneers of modern dairying, the ex- ponents of real dairy progress and development. 0. F. HUNZIKER. "'"^^ ; .;^^^^, ■■ ; ., . . .iigS ■^ '' ' '■ 1 ^ ,. -x-yn^^ ^^^' M ^^; ^ I t V::V&-;^>^-^ 1 L s^^ 1 ^ ^b ¥ |'\.:nRx ■^"'-■- 1^ p i;- r^'^'^ 1 H 1 ; ^^fl ?% ^^Y ^■^ / ?j8 '^^rmv^^r KL / '^ ^2 ' i ' V 1 j / Mr / . -/ P!i:;:l:.:;^:. ^U^ H . -^ W' i iJY\ 1 ^s^ ^ ^d^fc^j*! t 8 . . 1 1 :^isei^. 11^ The young man who chooses the occupation of a creamery butter maker must, in order to succeed, thoroly appreciate the necessity of acquiring a scien- tific knowledge of dairy subjects. The mechanical knowledge necessary in order to operate the machinery in a creamery is of minor importance, altho, of course, very essential. This knowledge can be acquired during the young man's apprenticeship, providing he is under the tutelage of a good butter maker and one who is not only willing but competent to impart information. The reason why things should be done in a certain way, or in other words, the scientific principles involved in dairy manufacture can best be learned at a Dairy School where these things are explained in lectures and facilities are provided for demonstration work in the various steps of dairy manufacture. Young men coming to the dairy school usually have in mind solely the art of making butter or cheese. They soon learn, however, that one who is but familiar with this part of the work is only a half-baked dairy- man; that the cow, the feed and the care of the herd are really the more important factors in the dairy in- dustry. It broadens their views and they look forward to the time when they can do even better than making butter or cheese. T. L. Haecker. Dairy education is not a goal, it is not the end sought; it is a tool to be used in attaining the desired end, and just as some can not drive a nail without marring the wood or even saw a board straight, so some may never profit by education. Education is training the eye to see, to read, and the mind to think and draw right conclusions from conflict- ing data and evidence. The seeker after truth asks two men, each of whom have been successful, "What is the proper thing to do under such circumstances." Their answers are diametrically opposite. It is then only the man who can analyze and figure out why seemingly opposite methods have brought these men success; who can derive from their answers that which will be of help in his condition. Again, education is not only training, but it is profit- ing by the experience of others; it is avoiding the experi- mental period, the cutting and trying and proving a truth that has already been proved and demonstrated many times over. It accepts that which is proved. The ancients knew that to keep milk sweet it must be cold. Science has shown us why, and the very be- ginner in the business of dairying can learn what tem- perature is necessary to secure the keeping of milk, he can learn whether or not he has that temperature and know that given that temperature, the milk received in the right condition will keep. Education then is but the tool that enables him to secure this information and profit by it immediately. Our dairy schools seek to teach men what is so, why it is so and how it may be profitably applied to every day business. They seek to give that amount of practice in the actual doing which chnches in the mind of the student the why and the wherefore. They can not make the dull man more bright or the lazy man more aggressive. They may give added incentive by contact with others, they can give him additional tools for his work. His success in using them depends on his own measure of ability and energy. Few men who are worth education need go long without it. The young man who expects to rise to a position of responsibility and individual independence, who hopes to have his own business as creameryman, dairyman or in any branch of the great dairy industry can afford to add to his natural endowment and to the practical experience which he has been fortunate enough to acquire, the help which comes with systematic training in high school and college. Whether it be a few weeks, a few months, a year, or a four years course need only be determined by personal, individual circumstances. Aim at what you want, then get as near it as possible. H. E. Van Norman. Knowledge plus practical experience plus determi- nation to get results is the ammunition required for fighting the battle which culminates in success. Knowledge broadens our comprehension. It is the eye through which we view our day's labor and where- with our work is changed from drudgery to pleasure. " Ignorance is the curse of God, Knowledge the wing wherewith we fly to Heaven ". (Shakespeare) m. mortensen MODERN BUTTER MAKING AND DAIRY ARITHMETIC BY MARTIN H. MEYER Formerly Assistant in Dairying and Instructor in Practical Butter Making at the University of Wisconsin, Madison, Wisconsin Author of A Treatise on Starters Madison, Wisconsin, Published by the Author, 19 10 Copyrighted 1910 By MARTIN H. MEYER Ccl.A' Overrun. Overread- ine test by .1% Butter fat in 20,000 lbs. of milk Pounds of butter made Per cent of true overrun Per cent of false overrun Per cent of decrease in overrun Correct test 4 % 800 lbs. 980 22.50 4.1% 820 lbs. 980 22.50 19.51 2.99 4.2% 840 lbs. 980 22.50 16.67- 5.83 4.3% 860 lbs. 980 22.50 13.95-F 8.55 4.4% 880 lbs. 980 22.50 11.36 11.14 4.5% 900 lbs. 980 22.50 8.88 13.62 THE OVEERtTN. 245 By reading the test .1 per cent too low, on 4 per cent milk the overrun is increased 3.14 per cent, Table VI. ; and by reading the test .1 per cent too high on 4 per cent milk, the overrun is reduced 2.99 per cent, Table No. VIII. This shows how easily the overrun may be reduced by reading the test while the test is too hot, and how easily it can be increased by reading the test when it is too cold, or by including the full meniscus, or by not including the meniscus in reading milk tests. Not only is the overrun affected by the above mentioned con- ditions, but not infrequently by deliberate over or under-reading of milk or cream tests. 37. The effect of under-reading cream tests. Table No. IX. Assuming that 800 lbs. of butter fat is re- ceived in 3,200 lbs. of cream testing 25 per cent. Butter made contains 80 per cent butter fat and the loss incident to its manufacture is 1 per cent. The Effect of TABLE IX. Underreading Cream Tests. 3200 lbs. Of cream No. of lbs. of butter fat in cream Total lbs. of butter fat in butter Per cent of butter fat in butter No. of lbs. of butter made Per cent of true overrun Per cent of false overrun due to reduced reading Per cent increase of overrun per .5% reduced reading Test Of cream Correct test 25 % 800 792 80 990 23.75 24.5% 784 792 80 990 23.75 26.27 2.52 24 % 768 792 80 990 23.75 28.90 5.15 23.5% 752 792 80 990 23.75 31.64 7.89 23 % 736 792 80 990 23.75 34.51 10.76 22.5% 720 792 80 990 23.75 37.50 13.75 The above table shows that for every .5 per cent reduction in reading 25 per cent cream, the overrun 246 MODERN BUTTER MAKING. is increased by about 2.7 per cent. The higher the cream tests are, the less is the increase in overrun due to reduced reading. 38. Table No. X., continuation of table No. IX. Showing increase in lbs. and value at 25c per lb. TABLE X. Continuation of Above Table No. IX. Showing Increase in lbs. and Value at 25 cents per lb. Beadinffs reduced from .5% to 2.5% Butter lbs. in- crease due to reduced reading daily Value at 25c per lb. daily Value during one year of 300 days Value when 6400 lbs. is received daily for one year .5% 19.8 $ 4.95 $1,485. $ 2,970 1. % 39.6 9.80 2,940. 5,880 1.5% 59.4 14.85 4,455. 8,910 2. % 79.2 19.80 5,940. 11,880 2.5% 99. 24.75 7,425. 14,850 That great care should be exercised at cream buying stations is clearly shown in the foregoing tables. The amount of butter fat bought should check up to within 2 per cent of the amount found to be in the cream when tested at the central station. When cream is bought at a receiving sta- tion the overrun is very likely to be from 2 per cent to 21/2 per cent, or even 4 per cent less than when cream is delivered directly to the creamery. 39. Butter fat in milk plus one-sixth equals the amount of butter made. The approximate amount of butter which can be made from any given number of pounds of butter fat is found by adding one-sixth of itself to the number of pounds of butter fat. This is true when butter having about 821/2 per cent butter fat is made. THE OVEREUN. 247 This was agreed upon by the Association of Ameri- can Agricultural Colleges and Experiment Stations at their ninth annual convention. The amount of butter which can be made from any given amount of butter fat also depends largely upon the skill of the operator and upon the compo- sition of the butter made; therefore the results ob- tained may be either higher or lower than results given in the preceding pages. The per cent of overrun is no true indication of the composition of butter, nor is the composition of butter a true indication of the per cent of over- run. 40. The effect of overreading cream tests. Assum- ing that 800 lbs. of butter fat are received in 3,200 lbs. of cream testing 25 per cent. Butter made con- tains 80 per cent butter fat. Loss incident to manu- facture is 1 per cent. TABLE XI. The Effect of Overreading Cream Tests. 3200 lbs. of cream No. of lbs. butter fat in cream Total lbs. of butter fat in butter Per cent of butter fat in butter No. of lbs. of butter made Per cent of false overrun. Due to over- reading Per cent of true overrun Per cent of reduc- tion of overrun by .5% Test of cream Correct test 25 % 800 792 80 990 23.75 25.5% 816 792 80 990 21.32 23.75 2.43 26 % 832 792 80 990 18.97 23.75 4.78 26.5% 848 792 80 990 16.74 23.75 7.01 27 % 27.5% 864 880 792 792 80 80 990 990 14.58 12.50 23.75 23.75 9.17 11.25 248 MODEEN BUTTER MAKING. In the foregoing table we find that for every .5 per cent overreading the overrun is reduced about 2.43 per cent and grows slightly less for every .5 per cent as the cream increases in richness of butter fat. 41. Continuation of table XI. showing a decrease in overrun in pounds of butter made, and the amount of loss at 25c per pound, when 3,200 lbs. of 25 per cent cream is read too high as in the preceding table. TABLE XII. Decrease in lbs. of butter per .5% over- reading of cream tests daily Daily loss at 25c per lb. Loss per year of 300 days Loss per year / /, . when 49,060 lbs. h ^^ of BftHfe are t^Ua received daily .5%= 20 lbs. $ 5.00 $1,500 $ 3,000 1. %— 401bs. 10.00 3,000 6,000 1.5%= 60 lbs. 15.00 4,500 9,000 2. %=801bs. 20.00 6,000 12,000 2.5%=1001bs. 25.00 7,500 15,000 The necessity of proper training for operating the Babcock test is again emphasized by the results presented in the foregoing tables. When we con- sider the foregoing chapter in its broadest sense it becomes evident that more and better training is necessary for the creamery operator, as well as better laws pertaining to this phase of the dairy industry. This is necessary for the protection of those who wish to perform their work honestly amidst unscrupulous persons. Taking a Dairy School course is undoubtedly the best way of gaining the knowledge necessary for properly performing all THE OVEEEUN. 249 the operations necessary for the handling of the Babcock test. 42. Main factors affecting the overrun. (a) Factors causing an increase in overrun : 1. Under-reading cream or milk tests. 2. Reading tests when too cold. 3. Not whirling test bottles long enough. 4. Short weight of test samples. 5. Reducing the per cent of fat in butter. 6. Increasing the per cent of moisture in butter. 7. Increasing the per cent of casein in butter. 8. Reducing losses to a minimum. 9. Giving short milk or cream weights. 10. Churning at high temperatures. 11. Working butter in wash water. 12. Washing butter with warm water. 13. Overworking butter in water when soft. (b) Factors causing a decrease in ovemm : 1. Overreading cream or milk tests. 2. Reading tests when sample is too hot. 3. Black specks and flocules in sample tested. 4. Overweight of test sample. 5. Too high per cent of fat in butter. 6. Too dry butter. 7. Decreasing the per cent of casein. 8. Spilling milk or cream or using a leaky churn. 9. Giving over weight in milk or cream. 10. Churning very cold cream and washing in very cold water. 11. Working hard butter at intervals instead of continuously until done. 250 MODEEN BUTTEE MAKING. 12. Draining butter too dry and adding cold, dry- salt. 13. Adding salt to cream or wash water. (c) Factors affecting overrun (market returns) after butter is made: 1. Dropping small pieces of butter during pack- ing. 2. Allowing butter to stick to churn, ladles and printers. 3. Leaky butter, losing water during handling and transit. 4. Repacking hardened butter. 5. Allowing butter to harden in churn before packing. 6. Incorrect weighing of butter when packed. CHAPTER ni. Standardization of Milk and Cream and Butter Fat Values. (a) Standardization of milk and cream. 43. Correct standardization of milk and cream is without doubt a very important factor in the suc- cessful handling of these products. The butter fat — the least variable constituent of milk — is the most valuable, hence the necessity of knowing accurately the per cent of butter fat contained in milk and cream. Many iastances are known of milk being sold con- taining much more butter fat than the price received for it would warrant without sustaining losses. On the other hand, without testing or standardizing milk, it is sometimes sold containing less butter fat than the legal standard. When the butter fat con- tent is too low the consumer is the loser, and the sale of such milk is illegal ; when the butter fat con- tent is too high, the dealer is the loser. Where the milk is bought for a certain considera- tion per hundred pounds, or by the fat content, based upon the Babcock test, and part of it is sold in the form of cream, the necessity of knowing the exact fat content is important. In many instances this milk is run through a separator with the machiae so adjusted as to skim about the desired per cent of fat. Even with the milk uniformly heated, the speed regular, and the same rate of inflow, a great variation in the fat content of cream will be no- 251 252 MODERN BUTTER MAKING. ticed. Even when all conditions are exactly the same there is always a little difference in the fat content of the cream. With some kinds of separators this variation in fat content is not nearly so great as with others, but the variation is always great enough to make it impossible to go by guess work and thereby incur losses which might be avoided by a little mathematical calculation. When once the general milk dealer becomes conscious of the fact that his competitor, by adopting the Babcock test, a method of standardization, and up-to-date dairy machinery makes greater profits in his line of work, he will not fail to learn and adopt methods which will put him on the same basis as his neighbor. Where milk and cream are bought only on the but- ter fat basis, they certainly must be sold on the same basis in order to avoid losses to the dealer, or cheat- ing the consumers. 44. The extent to which losses may be incurred by buying on the butter fat basis and selling by weight or measure may readily be seen by the fol- lowing: A milk and cream establishment receives about 20,000 pounds of milk per day, testing 4.5 per cent of butter fat. This milk, at an average price of 20c per pound of butter fat, would cost $180, figured as follows. 20,000 pounds of 4.5 per cent-f- 100=900 lbs. of butter fat, which, at 20c, would be $180. One-half of this 20,000 pounds of milk is sold as milk. Under contract the milk should con- tain 3.8 per cent of butter fat ; but when sold con- taining 4.5 per cent instead of 3.8 per cent the loss sustained by the dealer would be 4.5 per cent — 3.8 STANDAEBIZATION OF CEBAM. 253 or .7 per cent, or 70 lbs. of butter fat. Seventy pounds of butter fat at 20c a pound equals $14 losi each day on 10,000 lbs. of milk. 45. The other 10,000 lbs of milk is separated and sold in the form of cream at 20c a quart. The separator is adjusted so as to skim cream testing 20 per cent, but instead of skimming a 20 per cent cream, it skims a cream which tests 22 per cent. The loss in this case at 20c a quart would be as follows: The total fat in the cream is 450 lbs. 450-^20 per cent X 100=2,250 lbs. of 20 per cent cream. The number of pounds of 22 per cent cream would be 450-^22X100, or 2,045 lbs. The differ- ence would be 2,250—2,045 or 205 lbs. of cream. This would equal about 96 quarts, which, at 20c a quart, amounts to $19.20. The loss per day is— on the milk $14, on the cream, $19.20, making a total loss of $33.20. On 300 working days per year this would amount to a loss of $9,960. Suppose such a sized plant employs 15 men at an average wage of $60 per month. These losses alone would practically pay all but one of these men. Before actually figuring it out the variation in the fat content seems unimportant, but the above calcu- lation shows that it amounts to rather a snug sum in a year. And in 20 years it would amount to $199,200 — a handome sum, indeed, and enough to make even two partners feel comfortable and look cheerfully toward coming old age. This illustration bears out the statement that great losses can be incurred by buying milk on the basis of the butter fat content and selling by weight 254 MODEEN BUTTEE MAKING. or measure without regard to the fat content. In order to do justice to both the dealer and the con- sumer, milk should be bought and sold on the basis of the butter fat content. A butcher would not sell the different cuts of meat for the same price, nor would a miller sell fancy flour for the same price as the poorer grades. But does the average milk dealer ever think of selling milk and cream on an accurate butter fat basis? Many consumers of milk and cream do not know any difference between rich and poor cream, and the expression ''pure cream" usually conveys the meaning of a rich, heavy cream with a high per cent of butter fat. I am personally acquainted with some dealers and have a knowledge of their methods of handling milk and cream. The milk is separated and the richness of the cream regulated by the cream screw ; the cream at times varies from 2 to 3 per cent of that desired by the dealer. From the methods gen- erally employed in handling milk and preparing it for the market, it seems that a method by which milk and cream can be easily and accurately made to test the desired per cent of butter fat is indispen- sable. This is known as standardization. Standardi- zation, as applied to milk and cream, is a process by which skim milk can be extracted from or added to milk or cream, or whole milk or cream can be added to milk or cream to raise or lower the per cent of butter fat to the desired standard. The following problems with rules and analyses will show the methods which may be employed in standardizing milk and cream : STANDARDIZATION OF CEEAM. 255 46. Problems in standardization of milk and cream. 1. When cream is too low in per cent of fat. Rule I. Subtract the per cent of fat in the cream to be raised to a higher per cent from the desired per cent. Rule II. Subtract the desired per cent of fat from the per cent of fat in the cream to be used to add to the cream; divide the first difference by the second difference and multiply the quotient by the number of pounds of thin cream to be raised to a higher per cent of fat. The result is the number of pounds of higher testing cream to be added to the thin cream to be raised to a higher per cent of fat. The total cream would be obtained by adding the number of pounds of rich cream to the number of pounds of thin cream. Problem: 1,000 lbs. of 25 per cent testing cream is to be raised to 40 per cent with cream testing 50 per cent butter fat. Find how many pounds of the 50 per cent cream must be added to the 25 per cent cream to make it test 40 per cent. Solution: 40 per cent — 25 per cent=15 per cent. 15-^10^1.5. 50 per cent — 40 per cent=10 per cent. 1,000X1.5=1,500 lbs., the number of pounds of 50 per cent cream to be added to 25 per cent cream to raise it to 40 per cent. One thousand pounds plus 1,500=2,500 pounds= the whole amount of cream testing 40 per cent. Proof: 1,000 lbs. X 25 per cent=250 lbs. of butter fat; 1,500 lbs. X50 per cent=750 lbs. of butter fat; 750 plus 250=1,000 lbs., total butter fat ; 2,500 lbs. X40 per cent=l,000 lbs. 256 MODEEN BUTTER MAKING. 2. When cream is too high in per cent of fat. Bule I. From the test of the rich cream subtract the test of the desired cream. Rule II. Subtract the test of the thin cream to be added to dilute rich cream, from the desired test. Divide the first difference by the second and multi- ply the quotient by the number of pounds of rich cream to be lowered, and the result will be the num- ber of pounds of thin cream to be added to the rich cream to reduce it to the desired test. The total number of pounds of cream may be found by adding the number of pounds of thin cream to the number of pounds of rich cream. Problem: 1,000 lbs. of 50 per cent testing cream is to be diluted to 40 per cent with cream testing 25 per cent. How many pounds of 25 per cent must be added to give the desired test? Solution: 50 per cent — 40 per cent=10 per cent. 10 per cent^-15=.66666 plus. 40 per cent — 25 per cent=15 per cent. 1,000X.66666=666.66 plus pounds. 666.66=the number of pounds of thin cream to be added to reduce the heavy cream to 40 per cent. Total cream equals 1,000 lbs. plus 666.66 pounds or 1,666.66+ lbs. Proof: 1,000 lbs. X 50 per cent=500 lbs. of fat in 1,000 lbs. of 50 per cent cream. 666.66 lbs. X25 per cent=166.66 lbs. of fat in 666.66 lbs. of 25 per cent cream. 500+166.66=666.66, total pounds of fat in cream. 3. When a definite number of pounds of cream of a certain richness is wanted and cream or milk of less butter fat content is on hand, to find the ratio of STANDABDIZATION OF CREAM. 257 number of pounds of the two kinds to mix together to reduce the richer cream to the butter fat content desired : Rule I. Subtract the per cent of fat in the cream to be used to add to heavy cream to dilute it from the desired test. Rule II. Subtract the per cent of thin cream from the test of the rich cream and divide the re- mainder into the result obtained in the first sub- traction. Multiply the quotient by 100 and the re- sult will be the per cent of the rich cream to be used in standardizing the cream. Problem. How many pounds each of 50 per cent and 25 per cent cream must be mixed together to produce 1,000 lbs. of cream testing 40 per cent? Solution : 40 per cent — 25 per cent=15 per cent. 15 per cent-f-25 per cent=.6 per cent. 50 per cent — 25 per cent=25 per cent. .6X100=60 per cent, the per cent of 50 per cent cream to be used for the standardization of cream. 1,000 lbs. of 40 per cent is wanted. Sixty per cent of 1,000 lbs. equals 600 lbs., the number of pounds of 50 per cent cream necessary. 40 , per cent of the 25 per cent cream is to be added to the rich cream to reduce the test to 40 per cent. Proof: 1,000 lbs. of 40 per cent cream=400 lbs. butter fat. 60 per cent of 1,000 lbs.=600 lbs. of 50 per cent cream to be used. 40 per cent of 1,000 lbs.=400 lbs. of 25 per cent cream to be used. 17 258 MODERN BUTTER MAKING. 600 lbs. of 50 per cent cream=300 lbs butter fat. 400 lbs. of 25 per cent cream=100 lbs. butter fat. 400 lbs. total butter fat. 4. To find the ratio of the number of pounds of cream and skim-milk to be mixed to give a definite quantity of a definite richness: Rule I. Determine the quantity of fat in the de- sired cream by multiplying the number of pounds of cream wanted by the desired test and dividing the results by 100. Rule II. Divide the number of pounds of butter fat by the test of the cream on hand for use in standardizing, and multiply the quotient by 100. The result will give the number of pounds of cream to be used. The difference between the amount of cream desired and the amount of rich cream to be used will be the amount of skim milk to be added to the rich cream to produce the desired test. Problem: 600 lbs. of 30 per cent cream is wanted. Having cream on hand testing 40 per cent, and skim- milk, find how many pounds of each are needed to produce 600 lbs of 30 per cent cream. Solution: 600 lbs. X 30 per cent-f-100=180 lbs. of butter fat in the quantity of cream desired. 180 lbs.-f-40 per cent X 100=450 lbs. of 40 per cent cream to be used. 600 lbs. — 450 lbs.=150 lbs. of skim milk to be mixed with cream to reduce it to 30 per cent cream. 450 lbs. plus 150 lbs.=600 lbs. of cream testing 30 per cent. Proof: Butter fat in cream desired is (600X30) _i-100==180 lbs. Butter fat in mixture of 40 per cent cream and skim-milk is (450X40) -^100=180 lbs. STANBAEBIZATION OF CEEAM. 259 Butter fat in skim-milk none. The butter fat in tlie desired cream and in the mixture are the same; therefore calculations are correct. In order to prove whether the calculations have been correctly made, determine the fat in the two mixtures, and the fat in the desired cream. If calcu- lations have been correctly made, both results should be the same. 5. Three different methods which may be used to reduce the per cent of butter fat by adding skim- milk. (a) Rule I. Multiply the number of lbs. of cream to be diluted by the per cent of butter fat contained in the same, divide the product by 100. The quotient should then be multiplied by 100 and divided by the desired test. The difference between this result and the original amount of cream is the quantity of skim- milk to be added. Problem: 1,000 lbs. of cream testing 30 per cent butter fat is to be reduced to 25 per cent by adding skim-milk. How many pounds of skim-milk must be added? Solution : 1,000X30 — =300 lbs. butter fat in 1,000 lbs. 30 per cent cream. 300X100 =1,200 lbs., total cream having the desired 25 per cent of butter fat. 1,200—1,000=200 lbs. of skim-milk to be added to the original cream to reduce it to 25 per cent cream. (b) Rule II. Multiply the difference between the 260 MODEEN BUTTEE MAKING. test of the original cream by the number of lbs. of cream and divide the product by 100. Divide the result by the desired test, multiply the quotient by 100 and the result will be the number of pounds of skim-milk to be added to the cream to reduce the fat to the desired per cent. Problem: 1,000 lbs. of cream testing 30 per cent is to be reduced to 25 per cent by adding skim milk. How many pounds of skim-milk must be added ? Solution: 30—25=5. 1,000X5=5,000. 5,000-f-100=50. 50-f-25==2. 2xl00=lbs. of skim-milk to be added to 1,000 lbs. of 30 per cent cream to reduce it to 25 per cent. (c) Rule III. Multiply the number of pounds of cream to be diluted by the per cent of butter fat in the same and divide the product by the desired test. Find the difference between the quotient and the number of pounds of skim-milk to be added. Problem: 1,000 lbs. of cream testing 30 per cent is to be reduced to 25 per cent by adding skim-milk. How many pounds of skim-milk must be added ? Solution: 30X1,000 , . — =1,200, total pounds of cream, having the desired test. 1^200—1,000=200 lbs. of skim-milk, to be added. 47. When whole milk is used instead of skim-milk. The following rule and problem will illustrate STANDAEDIZATION OP CEEAM. 261 the methods employed when whole milk is used instead of skim-milk for diluting cream : Rule in. Divide the difference between the test of the original cream and the desired test, by the difference between the desired test and the test of the milk to be used, and multiply the quotient by 100. Problem: 1,000 lbs. of cream testing 30 per cent is to be reduced to 25 per cent by the addition of whole milk. How many pounds of milk testing 4 per cent must be added to give the desired test? Selution: 30—25=5; 25—4=21; 5^21=.238 lbs. of 4% milk to be added to every one lb. of 30% testing cream. To 1,000 lbs. 30% cream must be added .238X1.000=238 lbs. 4% testing milk. 48. Standardizing whole milk. The principles involved in the foregoing problems may also be applied in standardizing milk, except cases where skim-milk or cream is to be extracted. A few problems will be sufficient to show the meth- ods which can be employed. The following rule may be employed when the milk is too low in per cent of butter fat and it is necessary to determine how many pounds of skim- milk must be extracted to produce the desired per cent of butter fat in the milk. (a) Rule : Divide the per cent of butter fat in the milk by the per cent of butter fat desired ; multiply the quotient by the original amount of milk and the result will be the number of pounds of milk testing the desired per cent. The difference between this 262 MODERN BUTTER MAKING. result and the original amount of milk will be the quantity of skim-milk to be extracted. Problem: 2,000 lbs. of milk testing 3.5 per cent of butter fat is to be made to test 4 per cent. How many pounds of skim-milk must be extracted? Solution: 3.5-^=.875. 2,000X.875=1,750 lbs. of milk testing 4%. 2,000—1,750=250 lbs. of skim-milk to be extracted. (b) When skim-milk is used to lower fat in milk. When reducing the fat content in milk by adding skim milk, the following rule may be used: . Rule : Multiply the milk by its per cent of butter fat, divide the product by the desired per cent of butter fat, multiply the quotient by 100 and the prod- uct will be the total amount of milk with the de- sired test. The difference between the original quantity and the total quantity will give the number of pounds of skim-milk to be added to produce the desired per cent of butter fat. Problem: 5,000 lbs. of milk testing 4.5 per cent is to be reduced to 3.8 per cent butter fat. How many pounds of skim-milk must be added to reduce the test to 3.8 per cent of butter fat? Solution: 5,000X4.5=225 lbs. fat in milk. 225-f-3.8=59.21. 59.21X100=5,921. 5,921—5,000=921 lbs. of skim-milk to be added to 5,000 lbs. of 4.5% milk to reduce the test to 3.8%. The following solution of this problem may also STANDAEDIZATION OF CEEAM. 263 be used: 4.5-^3.8X5,000=5,921 lbs., the total amount of milk testing 3.8 per cent butter fat. 5,921—5,000=921, the whole amount of skim-milk added to reduce the test to 3.8%. These few problems will probably show that stand- ardization is not too complicated to be made use of in every cream and milk plant, where milk or cream of different richness is mixed and in this manner the per cent of butter fat is raised or lowered. Its economical and commercial advantages can not be questioned; and since we are legally and morally bound not to take advantage of the public, its use seems to be indispensable. The simplicity with which the desired richness may be calculated is ob- vious. 49. How to use viscogen as a thickening agent. Where viscogen is employed as a thickening agent, the following rule will help to simplify the work: Rule: Multiply the amount of cream to be treated with viscogen by two-thirds of the number of cubic centimeters used to neutralize the acidity in one pound of cream. The product divided by 950 cubic centimeters (the number of c. c. in one quart) will equal the number of quarts of viscogen to be added to the cream to be treated. Problem: If 6 cubic centimeters of viscogen will neutralize the acidity in one pound of cream, how many quarts of viscogen must be added to 800 lbs. of cream? Solution: Six c. e. of viscogen wiU neutralize acidity in one pound of cream. 264 MODEEN BUTTEE MAKING. % of 6 c. c=4 c. c. the quantity of viscogen to be added to one pound of cream. 800 lbs.X4=3,200, total number of cubic centime- ters of viscogen to be added to 800 lbs. of cream. 3,200 lbs.-^950=3.3 plus, the number of quarts of viscogen to be added to cream. 50. A few suggestions on the use of viscogen in commercial cream. The use of viscogen as a thickening agent has both advantages and disadvantages. Great care should be exercised in its use, which must always be regu- lated according to the condition of the cream. When too much is used, the cream has a disagreeable, dis- gusting flavor and aroma, and when such cream gets a little old, it is nothing short of rotten. There is no other defect in cream, whatever its source, which equals the rank flavor caused by too much viscogen. In practice it is well to use only one half the quantity necessary to neutralize the acidity of cream. When cream is very sweet, having an acidity of .1 per cent, it is well to add only % of the quantity necessary to neutralize the acidity of the cream. The poorer the cream and the higher its acidity, the greater is the quantity of viscogen which may be added to it. When viscogen is properly used, it serves a very good purpose and where its use is allowed by law it is de- sirable to use it. (b) Butter fat values. 51. Next to the values of standardization of milk and cream for city supply is the process of ascer- taining the relative value of butter fat in milk when sold in the form of milk, cream and butter at retail STANDAEDIZATION OF CEEAM. 265 prices, as compared with the wholesale butter fat value of milk. In the following the cost of manufacture and the expenses incident to selling the product will not be considered, the aim being to point out the possible value of butter fat as sold in different products. Cream or milk is usually sold both by measure and weight. The weight of cream varies according to its fat content. Pure butter fat has. a specific gravity of .9 against 1, the specific gravity of water ; consequently the richer the cream the lighter it is, and the thinner it is the heavier it is. Generally speaking the cream usually put upon the market weighs about 8.3 lbs. per gallon. Cream contain- ing from 18 to 22 per cent butter fat weighs a little more than this, while cream testing from 25 to 40 per cent weighs a little less per gallon. Milk does not vary in weight to any appreciable amount, therefore, no difference in weight of milk of different richness is made. The explanation of a few problems is necessary CQ order to illustrate methods that may be used in determining the approximate amount of butter which can be made from a given quantity of milk and the possible value of the butter fat when sold in the form of butter, cream and milk; these problems to be based upon an assumed retail price. Problems are also necessary to show the amount of butter fat in a quart or a gallon of cream of any richness and the price of cream according to the price of butter fat. 266 MODEEN BUTTEE MAKING. 52. Problems with explanations. I, Find the quantity of butter which may be made from 5,000 lbs. of milk testing 4 per cent butter fat ; also find the value of butter when the selling price is 22c a pound. Rule : Multiply the amount of milk by its test, in- crease the product by ^ of itself and multiply the sum by the price per pound. Solution: 5,000 lbs. X. 04=200 lbs. butter fat. 200 lbs.Xi=33V3 lbs. increase or overrun. 200 lbs.+33y3 lbs.=233y3 lbs. of butter made. 2331/3 lbs.X22c=$51.33, value of butter. Problem II. Find the value of the butter fat in 5,000 lbs. of 4 per cent milk when sold in the form of cream at the following prices: 20% cream at 20c, 24% cream at 25c per quart and 30 per cent crean? at 35c per quart. The weight of cream per gallon being as follows: 20% cream, about 8.4 lbs.; 24% cream, 8.3 lbs. ; 30% cream, 8.3 lbs. Rule: Multiply test of cream by the weight per gallon and multiply the amount of milk by its test; divide the latter by the former and multiply the quotient by the price per gallon. Solution (1). To find the value of milk when 20 per cent cream sells for 80c per gallon or 20c per quart: 20%.X8.4=168-f-100=1.68 lbs. butter fat in 1 gal- Ion of cream. 5,000 X .04=200 lbs. butter fat. 200-f-1.68X 100=119 gallons of 20% cream. 119X80 cents=$95.20, value of 5,000 lbs. of milk. STANDAEDIZATION OF CREAM. 267 Solution (2). To find the value of the milk when 24 per cent cream is sold for 25c per quart or $1 per gallon. 24%X8.3=199.2. 5,000 lbs. X. 04=200 lbs. butter fat in milk. 199.2-f-100=1.99 plus lbs. butter fat in 1 gallon of cream. 200-^1.99X100=100.5 gallons of 24% cream. 100.5 X$1.00=$100.50, value of 5,000 lbs. of milk. Solution (3). To find the value of the milk when 30 per cent cream is sold for 35c per quart or $1.40 per gallon. 30% X 8.3=249. 5,00OX. 04=200 lbs. butter fat in milk. 249-^100=2.49 lbs. of fat in 1 gallon of cream. 200-f-2.49=80.4 gallons of 30% cream. 80.4X1.40=$112.56, value of 5,000 lbs. of milk. If 5,000 lbs. of 4% milk were sold in the form of milk we find the values to be as follows : 5,000 lbs. milk-^8.5 lbs. (weight of 1 gallon) = 588.2 gallons. 588.2X20 cents=$117.64, value of milk. 53. Comparative values. When sold as butter at 22c per lb., value $ 51.33 "When sold as 20% cream at 80c per gallon, value 95.20 When sold as 24% cream at $1.00 per gallon, value , 100.50 When sold as 30% cream at $1.40 per gallon, value 112.56 When sold as milk at 20c per gallon, value. . . 117.64 268 MODERN BUTTER MAKING. From the table it will readily be seen that milk when sold in the form of milk has the highest market value. However, we must also consider that in mar- keting milk there are many expenses. There are losses in selling, and when the bottling system is used there is additional expense of this process, together with the loss from breakage of bottles, etc. The washing and sterilizing of the bottles is also an item which must not be overlooked. When cream is the main article sold in a city milk supply plant, and some butter is made, the buttermilk and skim milk can in many cases be disposed of to great ad- vantage. The skim-milk can be made into cottage cheese and the buttermilk sold either plain or creamed. There is sometimes quite a demand for creamed buttermilk, especially during the summer months. 54. To find the value of a pound of butter fat when cream sells at 25c per quart or $1 per gallon proceed as follows: Multiply the test of the cream by the weight per gallon and divide the product by 100. Divide the price per gallon by this quotient and the result will be the price of 1 lb. of butter fat. 24 X 8.3=1.99 lbs. fat in 1 gallon of 24% cream. $1.00 H-1.99=50c, price per pound of butter fat. CHAPTER IV. Problems Relating to the RtecEiviNG and Separating of Milk. 55. To find the amount of butter fat in milk. Problem: How many pounds of butter fat are there in 30,000 pounds of milk testing 4 per cent? Rule. Multiply the number of pounds of milk by its test, and divide the result by 100. This will give the number of pounds of butter fat in the milk. Solution. 30,000. X4=120,000. : 120,000.-f-100= 1,200. lbs. Explanation: Every 100 lbs. of milk contains 4 per cent, .04 or 4/100 of butter fat. When every hundred pounds of milk contains four pounds of butter fat, there will be as many pounds of butter fat in 30,000 lbs. of milk as 100 is contained in (30,000X4) or 1,200 lbs. Problems for Practice. (1). How many pounds of butter fat in: 8,000 lbs. of milk testing 4 %? Ans. 320. lbs. (2). 10,500 lbs. of milk testing 3.5%? Ans. 367.5 lbs. (3). 18,750 lbs. of milk testing 3.9%? Ans. 731.25 lbs. (4). 50,000 lbs. of milk testing 3.8%? Ans. 1,900. lbs. (5). 100,000 lbs. of milk testing 4.1%? Ans. 4,100. lbs. 270 MODEBN BUTTEE MAKING. 56. To find butter fat losses in skim milk. Problem: How much butter fat is lost in 25,000 lbs. of skim milk testing .09 per cent? Rule: Multiply the skim milk pounds by its test, divide the result by 100 and point off as per rules 5 and 9. Solution : 25,000X. 09=2,250 ; 2,250^100=22.5 lbs. Ans. Explanation: Every 100 lbs. of skim milk con- tains .0009 or 9/10,000 or .09 per cent butter fat. If every 100 lbs. skim milk contains .09 per cent but- ter fat, then 25,000. lbs. will contain 25,000X.09% or 2,250.00. Dividing this by 100 gives the result, 22.50 lbs. Problems for Practice. How many pounds of butter fat are lost in : 1. 7,500. lbs. of skim milk testing .06%? Ans. 4.5 lbs. 2. 10,500. lbs. of skim milk testing .09%? Ans. 9.45 lbs. 3. 25,780. lbs. of skim milk testing .15%? Ans. 38.67 lbs. 4. 30,000 lbs. of skim milk testing .03%? Ans. 9. lbs. 5. 30,000. lbs. of skim milk testing .09% ? Ans. 27. lbs. 6. 30,000. lbs. of skim milk testing .1 % ? Ans. 30. lbs. 7. 30,000. lbs. of skim milk testing .2 %? Ans. 60. lbs. 8. 30,000. lbs. of skim milk testing .3 % ? Ans. 90. lbs. Note.— Losses of butter fat in buttermilk are determined the same way as losses of butter fat in skim milk and come under the lame rule. CREAMEEY PEOBLEMS. 271 57. To find the per cent of cream from milk. Problem: 5,000 lbs. of milk, delivered 800 lbs. of cream. Find the per cent of cream from milk. Rule: Divide the total cream pounds by the total milk pounds, multiply the quotient by 100; the re- sult is the per cent of cream from milk. Solution : 800^5000=.16 X 100=16 % . Ans. or 800x100-^-5000=16%. Ans. or 800/5000 reduced = 4/25, expressed decimally 4/25 =.16 or 16%. Explanation: When 5,000 lbs. milk give 800 lbs. cream, 1 lb. of milk will give as many pounds as 5^000 is contained in 800 lbs. cream, which is .16; 100 lbs. milk will give IOOX.16 or 16 lbs. or 16%. Ans. Problems for Practice. What is the per cent of cream from: 1. 8,780 lbs. milk delivering 900 lbs. cream? Ans. 10.25%). 2. 10,900 lbs. milk delivering 1,275 lbs. cream? Ans. 11.69%. 3. 20,785 lbs. milk delivering 3,750 lbs. cream? Ans. 13.23%. 4. 35,000 lbs. milk delivering 7,000 lbs. cream? Ans. 20. %. 5. 50,000 lbs. milk delivering 9,500 lbs. cream? Ans. 19. %. 58. To find the per cent of cream from milk, when the amount of skim milk and cream separated are known. Problem: What is the per cent of cream from 272 MODERN BUTTEE MAKING. milk when a separator delivers 10 lbs. of cream to every 40 lbs. of skim milk? Rule: Add the cream and skim milk separated at one time, together; divide the cream pounds by the sum, and multiply the quotient by 100. The re- sult will be the per cent of cream from milk. Solution: 10+40=50; 10^50=.2% cream from 1 lb. milk. Or 10+40=50; 10X100-^-50=20% cream from 300 lbs. of milk. For every 50 lbs. of milk we get 10 lbs. of cream and we get as man pounds of cream for every pound of milk as 50 is contained in 10, which is .2, and from every 100 lbs. of milk we get 100 X.2 or 20 lbs. or 20%. Problems for Practice. What is the per cent of cream from milk when a separator delivers: 1. 10 lbs. of cream and 35 lbs. of skim milk? Ans. 22+%. 2. 12 lbs. of cream and 60 lbs. of skim milk? Ans. 16+%. 3. 15 lbs. of cream and 75 lbs. of skim milk? Ans. 17—%. 4. 20 lbs. of cream and 88 lbs. of skim milk? Ans. 18+%. 5. 24 lbs. of cream and 95 lbs. of skim milk? Ans. 20+%. 59. To find the amount of cream of any desired test which milk of any richness can yield. CEEAMEEY PEOBLEMS. 273 Problem: How many pounds of 20 per cent test- ing cream will 800 lbs. of 4 per cent milk yield ? Rule : Divide the milk test by the cream test and multiply the quotient by 100. Multiply this result by the number of pounds of milk; divide result by 100. The quotient is the number of pounds of cream. Salution: 4/20=.2; .2X100=20; or 4/20X100= 20%; (800X20)-f-100=160 lbs. Ans. Milk. lbs. Milk test. Cream test. or 800 + 4 -^-:20— 160 cream lbs. Ans. Problems for Practice. How much cream can be obtained from the fol- lowing : Milk lbs. Milk test. Cream test. 1. 255 4 % 20% Ans. 51. lbs. 2. 340 5 % 30% Ans. 56.6 lbs. 3. 3,250 3.5% 18% Ans. 631.9 lbs, 4. 10,550 3.8% 25% Ans. 1,603.6 lbs. 5. 20,670 4.2% 40% Ans. 2,170.3 lbs. 60. To find the amount of cream when the per cent of cream from milk, and the milk pounds, are known. Problem: The per cent of cream from 35,000 lbs. of 4 per cent milk is 22.5. Find the amount of cream. Rule: Multiply the milk pounds by the per cent of cream from milk and divide the result by 100. The quotient will be the cream pounds. Solution: 35,000X22.5=787,500; 787,500-^100= 7,875; or (35,000^100) X 22.5=7,875 lbs. Ans. 19 274 MODEEN BUTTER MAKING. Explanation : Every 100 lbs. of milk delivers 22.5 lbs. of cream. Therefore, there are as many times 22.5 lbs. of cream delivered as 100 is contained in 35,000, which is 350; 350X22.5=7,875 lbs., the total amount of cream. Problems for Practice. Find the amount of cream when the per cent of cream from: 1. 5,507 lbs. of milk is 10.5% ? Ans. 578.23 lbs. 2. 10,780 lbs. of milk is 12.7% ? Ans. 1,369.06 lbs. 3. 15,872 lbs. of milk is 15.2% ? Ans. 2,412.54 lbs. 4. 20,975 lbs. of milk is 20.1% ? Ans. 4,215.9 lbs. 5. 40,435 lbs. of milk is 23.3%? Ans. 9,421.35 lbs. 61. To find the approximate amount of cream, knowing the test of cream, and the amount and test of the whole milk. Skim milk losses are l^i per cent of the total fat in the milk. Problem: What is the amount of cream received from 25,000 lbs. of milk testing 4 per cent, the cream testing 30 per cent and the butter milk losses being 1^4 pel* cent of the fat in the milk? Ride: I. Multiply the amount of milk by its test, and multiply this result by the per cent of loss. II. From the total fat in the milk, subtract the loss, and divide the remainder by the cream test, multiply the quotient by 100 and the result will be the amount of cream. 25,000X4%=1,000 lbs.; l,000XliA%=12.50 loss. 1,000—12.50=987.5 ; (987.5-^30) X 100=3,291.66 lbs. cream. Ans. Explanation: First find the amount of butter fat CEEAMEEY PEOBLEMS. 275 in the milk and from that subtract loss, which is 12.5; this leaves 987.5 lbs. butter fat in the cream. Each 100 lbs. of cream contains 30 lbs. butter fat, and there will be as many 100 lbs. of cream as 30 is contained in 987.5, and the total cream will be 100 times this number, or 3,291.66 lbs. cream. Problems for Practice. Find the approximate amount of cream when losses incident to separating are in each case 1^4 V^^ cent of the total fat in milk. Milk lbs. Milk test. Cream test. Cream lbs. Ans. 1. 12,760 4 % 25% 2,016 2. 17,590 3.9% 20% 3,387 3. 25,300 3.8% 18% 5,211 4. 50,000 4.1% 35% 5,784 5. 50,000 4.1% 50% 4,048 62. To find amount of skim milk from any quan- tity of milk. Problem: A creamery receives 24,000 lbs. of whole milk; 80 lbs. of skim milk out of every 100 lbs. of milk are returned to patrons. How much skim milk does the creamery return to patrons! Rule: Multiply milk pounds by per cent of skim milk returned and divide result by 100. The quo- tient is number of skim milk pounds. Solution: 24,000X80=1,920,000; 1,920,000-^100 =19,200 lbs. Ans. Explanation: For every 100 lbs. of whole milk delivered the patron gets 80 lbs. of skim milk. The total skim milk will be (24,000x80)-^100=19,200 lbs. 276 MODEEN BUTTEB MAKING. Problems for Practice. Find amount of skim milk returned to patrons when : Skim milk Pounds Milk received returned returned 1. 10,000 lbs. 80% 8,000 lbs. 2. 15,780 lbs. 85% 13,413 lbs. 3. 20,340 lbs. 90% 18,306 lbs. 4. 50,590 lbs. 75% 37,942 lbs. 5. 50,590 lbs. 80% 40,482 lbs. 63. To find the approximate test of cream, know- ing the amount and test of milk, the pounds of cream separated, and allowing 1^4 per cent me- chanical loss on the total butter fat. Problem: 45,000 lbs. of milk testing 4 per cent gave 3,500 lbs. of cream. Find the test of cream. Rule: Find the total butter fat in milk and mul- tiply this by the per cent of loss. Subtract the loss from the total butter fat and divide the remainder by the number of pounds of cream. Multiply the quotient by 100 and the result will be the test of the cream. Solution: 45,000 X 4 %-r-100=l,800; (1,800X1%) X100=22.5; 1,800—22.5=1,777.5; (1,777.5-^3,500) X 100=50.6%. Ans. Explanation: From the total butter fat in the milk we subtract the loss. Then we divide the re- maining butter fat by the total amount of cream. This gives the butter fat in one pound of cream, and 100 lbs. of cream will test 100 times the butter fat in one pound of cream, or 50.8 per cent. CREAMEEY PROBLEMS. 277 Problems for Practice. Find the test of cream when: Cream Cream test. Separated. Milk lbs Milk test. Ans. 1. 350 lbs. 4,000 4 % 45.1% 2. 1,500 lbs. 9,500 3.9% 24.3% 3. 2,800 lbs. 20,780 4 % 29.3% 4. 5,550 lbs. 45,000 3.8% 30.4% 5. 5,550 lbs. 45,000 3.9% 31.2% 64. To find the approximate average test of skim milk, knowing the total butter fat in milk and in cream separated, and knowing the number of pounds of skim milk. Problem: Milk contained 2,540. lbs. butter fat, and the cream contained 2,500. lbs. butter fat. There were 56,108. lbs. skim milk. Find the test of skim milk. Rule: Divide the difference in the amount of butter fat in milk and cream by the skim milk pounds, and multiply quotient by 100. The result is the test of the skim milk. Solution: 2,540—2,500=40; (40-f-56,108)Xl00= .071%. Ans. Explanation: First find the difference, which is 40 lbs. Then by dividing this by the number of pounds of skim milk, and multiplying by 100, we get the test per hundred pounds or in per cent. 278 MODERN BUTTER MAKING. Problems for Practice. Find the test of skim milk in the following : Fat in milk. Fat in cream. Lbs. skim milk. Ans. 1. 295. lbs. 290. lbs. 3,120. .16% 2. 900. lbs. 892. lbs. 17,460. .046% 3. 3,250. lbs. 3,225. lbs. 39,812. .062% 4. 5,675. lbs. 5,520. lbs. 133,440. .11% 5. 5,675. lbs. 5,440. lbs. 133,440. .17% 65. Table showing relative loss in skim milk at 25c per lb. of butter fat. Average skim milk test .05 to .03 per cent. TaUe SJioidng Relative Loss in Skimming at 25 cents per lb. of Butter Fat. Average Skim Milk Tests .05 to .3%. Skim milk lbs. Daily Test % Loss in lbs. At 25c per lb. daily 10,000 .05% 5. $1.25 10,000 .08% 8. 2.00 10,000 .10% 10. 2.50 10,000 .13% 13. 3.25 10,000 .15% 15. 3.75 10,000 .18% 18. 4.50 10,000 .20% 20. 5.00 10,000 .23% 23. 5.75 10,000 .25% 25. 6.25 10,000 .28% 28. 7.00 10,000 .30% 30. 7.50 CREAMEEY PROBLEMS. 279 The above table should serve to bring out more clearly the fact that in creamery work, not unlike brokerage, it is the fractional parts which are very important and essential factors in making for the success or failure of the business. The same comparative losses occur in buttermilk, therefore, it is just as important to churn so as to reduce buttermilk fat losses to the minimum. Q6. Promiscuous problems. 1. A creamery receives 2,480 lbs. of milk testing 4.2 per cent. The skim milk is 80 per cent of the whole and tests .1 per cent fat. What is the (a) per cent of cream taken, and (b) the test of the ereaml Ans. (a) 20 per cent; (b) 22.6 per cent. 2. A creamery receives 30,000 lbs. of milk testing 3 J per cent, of which 85 per cent is skim milk test- ing .08 per cent. Find (a) the fat lost in skim milk, (b) test of cream, (c) per cent of cream from milk, (d) total weight of cream. Ans. (a) 20.4 lbs.; (b) 24.21 per cent; (c) 15 per cent; (d) 4,500 lbs. 3. At a creamery 80 per cent of the milk is skim milk, testing .05 per cent, and is returned to the patrons. The total skim milk is 2,880 lbs. Find the (a) total number of pounds of milk received, and (b) the total fat lost in the skim milk. Ans. (a) 3,600 lbs.; (b) 1.44 lbs. 4. Cream tests 20 per cent butter fat and the total milk, which is 35,000 lbs., tests 4 per cent. Find (a) the per cent of cream taken from the milk, and (b) the total weight of cream, allowing a loss of 1 per cent butter fat in skimming. Ans. (a) 19.8 per cent; (b) 6,930 lbs. 280 MODEEN BUTTER MAKING. 5. Cream tests 30 per cent, the total weight is 2,250 lbs. ; 10 lbs. of fat were lost in skimming. Find (a) the per cent of loss in skimming on the total butter fat in milk, (b) the number of pounds of milk which tests 4 per cent, and (c) the per cent of cream from milk. Ans. (a) 1.5 per cent; (b) 17,125 lbs.; (c) 13.2— per cent. 6. A gathered cream plant receives 5,000 lbs. of cream daily, testing 32 per cent butter fat, and makes 1,850 lbs. butter. To the cream is added 800 lbs. of skim milk starter. The buttermilk tests .2 per cent. Find (a) loss of fat in buttermilk, (b) per cent of buttermilk from cream, (c) per cent of loss of butter fat on total fat in cream. Ans. (a) 7.9 lbs.; (b) 68+ per cent; (c) .49 per cent. 7. What will be the (a) test of cream, (b) per cent of cream from milk, and (c) test of skim milk when 50,000 lbs. of 4 per cent milk are received and the skim milk is 85 per cent of the whole; al- lowing a loss of 20 lbs. of butter fat in the skim milk? Ans. (a) 26.4 per cent; (b) 15 per cent; (c) .047 per cent. 8. A creamery in good running order loses 1% per cent of the total fat in milk. When separating is carelessly done a creamery may lose 3% per cent of the total fat in milk. When a creamery received 100,000 lbs. of milk per day testing 4 per cent and the cream is 12 per cent of the milk, find (a) the difference in the test of the cream, and (b) the dif- ference in loss when butter fat sells at 30 cents per pound. CREAMEEY PROBLEMS. 281 Ans. (a) When loss is 3I/2 per cent instead of 1% per cent, cream tests .67 per cent less. Ans. (b) When loss is 3I/2 per cent instead of 1% per cent, loss at 30c per lb. is $24.00 per day. B. Problems Pertaining to Cream Ripening. 67. To find how many pounds of starter should be added to cream of any richness to reduce it to any desired per cent of butter fat, assuming that a skim milk starter is used. Problem: How many pounds of starter will it re- quire to reduce 3,000 lbs. of 30 per cent cream to 25 per cent cream? Rule. I. Multiply the cream pounds to be re- duced by its test and divide the result by 100. The result will be the total fat in the richer cream. II. Divide the total butter fat by the desired test of cream and multiply the quotient by 100. From this result subtract the cream pounds to be diluted. The difference will be the amount of starter to be added. Solution: 3,000X30-^100=900. lbs. butter fat; (900-^25) X100=3,600— 3,000=600 lbs. Ans. Explanation: By subtracting 25 from 30, we get 5, which is % of the test of the desired cream. The same relation exists between the amount of cream to be diluted and the amount of starter necessary to dilute it. Therefore, it must be increased by % of itself, or 600 lbs. of a skim milk starter. 2 MODEEN BUTTEE MAKING. Problems for Practice. Find the amount of starter to be added to Cream lbs. Cream test. Reduced to. Ans. 1. 3,275 lbs. 30% 25% 675 lbs. 2. 4,560 lbs. 40% 30% 1,520 lbs. 3. 6,780 lbs. 50% 35%. 2,905 lbs. 4. 10,500 lbs. 30% 25% 2,100 lbs. 5. 10,500 lbs. 30% 20% 5,250 lbs. 68. To find the number of pounds of starter to be added to cream, when the per cent of starter is known. Problem: 20% of starter is to be added to 3,080 lbs. of cream. How many pounds of starter will it require ? Rule: Multiply the cream pounds by the per cent of starter and divide the result by 100. The quotient will be the number of pounds of starter required. Solution: 3,080X20=61,600; 61,600-f-100=616. Ans. Explanation : By adding 20 per cent of starter we add 20 lbs. to every hundred pounds of cream. Therefore we must add as many times 20 lbs. as there are hundreds in the amount of cream (3,080), or 616 lbs. Problems for Practice. How many pounds of starter are required when: 1. 10% of starter is to be added to 2,570 lbs. cream. Answer, 257 lbs. 2. 15% of starter is to be added to 3,800 lbs. cream. Answer, 570 lbs. CEEAMEEY PEOBLEMS. 283 3. 25% of starter is to be added to 4,800 lbs. cream. Answer, 1,200 lbs. 4. 30% of starter is to be added to 5,780 lbs. cream. Answer, 1,734 lbs. 5. 50% of starter is to be added to 8,500 lbs. cream. Answer, 4,250 lbs. 60. To find the per cent of starter added when any quantity of starter was added to any quantity of cream. Problem: 670 lbs. starter were added to cream, making a total of 3,200 lbs. of cream. What per cent of starter was added ? Rule: From the number of pounds of cream sub- tract the number of pounds of starter, divide the difference into the number of pounds of starter; multiply the quotient by 100 and the result is the per cent of starter. Solution : 3,200—670=2,530 ; (670^2,530) X 100= 26.5%. Ans. Explanation: When any amount of starter has been added to cream we first subtract the number of pounds of starter from the total number of pounds given. This gives the number of pounds of cream before the starter was added. By dividing the num- ber of pounds of cream into the number of pounds of starter and multiplying by 100 we get the per cent of starter. What is the per cent of starter when : 1. 1,600 lbs. of cream contain 300 lbs. of start- er? Ans. 23.07%. 2. 4,000 lbs. of cream contain 600 lbs. of start- er? Ans. 17.6%. 284 MODERN BUTTER MAKING. 3. 4,500 lbs. of cream contain 800 lbs. of start- er? Ans. 21.6%. 4. 30,000 lbs. of cream contain 6,000 lbs. of start- er? Ans. 25%. 5. 30,000 lbs. of cream contain 7,600 lbs. of start- er? Ans. 33.4%. 70. Knowing the acidity of both cream and starter find the acidity after starter is added to cream. Problem: The acidity of the starter is .70% ; the acidity of the cream (100 lbs.) is .22%. 30% (or 30 lbs.) of starter is added to every 100 lbs. of cream. Find acidity of cream after starter is added. Rule: To the acidity in the cream add the acidity in the per cent of starter (30 lbs.) to be added, and divide the sum by 100+the per cent to be added. Multiply the quotient by 100 and the result will be the acidity of cream after starter is added. Solution : (70X3O)h-100=.21 ; .21+.22=.4i3 ; .43-f-130=.0033; .0033X100=.33%. Ans. Explanation: 100 lbs. cream tests .22% acidity. 100 lbs. starter tests .70%. We add 30% or 30 lbs. of starter to each 100 lbs. of cream. We have .22% acidity in each 100 lbs. cream. We have 30 lbs. of starter at .70% acidity=.21 acidity. The total acidi- ty is .43. The total cream and starter is 130 lbs. and the total acidity of cream and starter is .43; 43-^130=.0033. .0033X100==.33%, the acidity of 100 lbs. of cream after the starter is added. CREAMERY PROBLEMS. 285 Problems for Practice. Find acidity of cream when the per cent of start- er to be added is : Starter. Acidity. Cream Acidity. Ans. 1. 10% .65% .25% .286% 2. 15% .75% .20% .27 % 3. 20% .60% .23%. .29 % 4. 25% .68% .20% .296% 5. 30% .70% .26% .361% 71. To find acidity of cream when sweet milk or water is used to reduce acidity. Problem: What will be the acidity of cream hav- ing .65% acidity, when (a) 12% of water is added; (b) when 12% of milk with an acidity of .15% is added? Rule I. Divide the per cent of acidity in cream to be diluted, by 100+the per cent of water to be added. Multiply the quotient by 100, and the result will be the per cent of acidity after diluting. Rule n. Multiply the per cent of milk to be added by its acidity. To this add the acidity in per cent in the cream to be diluted ; divide the sum by 100-f-the per cent of milk to be added and multiply the quotient by 100. The result is the acidity of the diluted cream. Solution: (a) .65^(100+12) =.0058; .0058X100 =.58%, Ans. (b) .65+(12X.15)=.668; .668-f-112= .0059; .0059X100=.59%. Ans. Explanation: It will be seen that when we add 12% we add 12 lbs. to each 100 lbs. of cream. This makes 112 lbs. of cream. When the addition is 286 MODEEN BUTTER MAKING. water, 112 lbs. of the cream contains .65% acid and 100 lbs. of the cream will test as many per cent as 112 is contained in .65%. This quotient multiplied by 100 equals .58%. When we add milk which has some acidity, we must first find out how much acidity is added to the cream. This we find by multiplying the amount added by its test. "We add the test of acidity of the cream and the acidity in the milk, which in this case is .018+.65, which equals .668. This is the acidity of 112 lbs. of diluted cream. To find the per cent of acidity we divide .668 by 112 which gives us .0059. .0059X100=.59%. Ans. Problems for Pracjtice. Find the per cent of acidity in cream when: 1. 10% water is added to cream having .75% acid. Ans. (a) .68+%, (b) .69%. 2. 15% water is added to cream having .80% acid. Ans. (a) .695%, (b) .715%,. 3. 20% water is added to cream having .75% acid. Ans. (a) .625%, (b) .65%. 4. 10% water is added to cream having .65% acid. Ans. (a) .59%, (b) .60%. 5. 15% water is added to cream having .65% acid. Ans. (a) .56%, (b) .58%?. When milk with an acidity of .15% was used instead of water in the above problems the answers marked b show the result. 72. Promiscuous problems. 1. A creamery receives daily 1,500 lbs. of cream testing 38% butter fat. The test is to be reduced to 30% by adding a skim milk starter, (a) How many CREAMEEY PROBLEMS. 287 pounds of starter must be added"? (b) What per cent of starter is added? Ans. (a) 400 lbs., (b) 26%%. 2. The average test of 20,000 lbs. of hand sep- arator cream is 30%. After adding all the rinsings the test is 291/2 %• The test for churning should be 25%. Find (a) the amount of rinse water added; (b) amount of starter required for reducing test to 25%. Ans. (a) 339 lbs.; (b) 3,661 lbs. 3. The manager of a creamery notified the but- ter maker that all cream should have not more than .5% acidity at the time of churning. A lot of cream, on arrival at the creamery had an average acidity of .62% and tested 40% butter fat. Water was to be used as a diluent. Find amount of water necessary to reduce the acidity of (a) 2,200 lbs. of cream; (b) 2,000 lbs. of cream to .5% acidity. Ans. (a) 528 lbs. ; (b) 480 lbs. 4. 1,200 lbs. of 40%. testing cream tested 25% after the starter was added. Find (a) amount and (b) per cent of starter. Ans. (a) 720 lbs.; (b) 60%. 5. A creamery receives 50,000 lbs. of 4% milk and 20,000 lbs. of 35% cream. 2% of the fat in the milk was lost in skimming. After mixing the cream sep- arated from milk with cream received the test was 37% fat. Find amount of cream separated and amount of starter necessary to reduce the test of the cream to 32% fat. Ans. Separated cream, 4,216 lbs. ; starter necessary, 8,000 lbs. 73r Problems bearing on the manufacture of butter. To find the amount of butter fat lost in butter- 288 MODERN BUTTER MAKING. milk, when the number of pounjds of cream and ibut^ ter are known. Problem: 980 lbs. of butter were made from 3,200 lbs. of cream; buttermilk tested .2 per cent. What was the loss in butter fat? Rule: From pounds of cream subtract pounds of butter made ; multiply remainder by buttermilk test and divide product by 100. The quotient will be pounds butter fat lost. Solution: 3,200—980=2,220 lbs. buttermilk; (2,- 220X.20)-^100=4.44 lbs. butter fat lost. Explanation : Aside from the water used for rins- ing cream utensils, the difference between the amount of cream churned and butter made will give the pounds of buttermilk. This multiplied by the test and divided by 100 will equal pounds of butter fat lost. Problems for Practice. Find pounds of butter fat lost. Butter lbs. Cream lbs. B. M. test. Ans. 1. 995 lbs. 3,500 lbs. .20% 5.+lbs. 2. 2,550 lbs. 9,670 lbs. .15% 10.6 lbs. 3. 8,700 lbs. 20,675 lbs. .10% 11.9 lbs. 4. 9,250 lbs. 25,456 lbs. .05% 8.1 lbs. 5. 9,250 lbs. 25,456 lbs. .15% 24.2 lbs. 74. To find the per cent of fat in buttermilk when the pounds of cream, its test, the per cent of fat in butter and the number of pounds of butter are given. Problem: 3,540 lbs. of 30% cream made 1,290 lbs. butter with a fat content of 82%. What is the test of the buttermilk? CEEAMERY PROBLEMS. 289 Rule I. Multiply the number of pounds of cream by its test and from the result subtract the result obtained by multiplying the pounds of butter by the per cent of fat it contains. Rule II. Subtract the number of pounds of butter from the number of pounds of cream and divide this result into the difference between the fat in the cream and the butter. Multiply the quotient by 100 and the result will be the test of buttermilk. Solution: 3,540X30=1,062; butter fat in cream. 1,290X82=1,057.8 butter fat in butter. 1,062— 1,057.8=4.2 ; 4.2-^(3.540—1,290) Xl00=.18%. Explanation: First find the number of pounds of butter fat in the cream and in the butter made from it. These are 1,062 and 1,057.8 lbs. respectively. Now subtract the total butter made, from the total cream pounds, and the difference, which is 2,250 lbs., is the buttermilk. Now divide the fat loss — 4.2 lbs. by 2,250 (the buttermilk) and the result is the test of the buttermilk, .18%. Ans. 75. To find the number of pounds of butter, with a given per cent of fat, which can be made from a given number of pounds of butter fat in cream, al- lowing a loss of a certain per cent of fat in the but- termilk. Problem: How many pounds of butter, having 82.5% fat, can be made from 4,560 lbs. of 32% cream, the loss in buttermilk being .75% of the total fat in cream ? Rule: Multiply cream pounds by the test of cream ; divide the result by 100. This gives total cream fat. Multiply this by the per cent of loss; 290 MODEEN BUTTER MAKIISG. divide result by 100. This gives loss of fat. Divide the difference between loss and total fat in cream by the per cent of fat in butter; multiply quotient by 100. Result is number of pounds of butter which can be made. Salution: (4,560X32)-f-100=l,459.2; (1,459.2X .75)-^100==10.94; 1,459.2— 10.94=-1,448.26; (1,448.26 -f-82.5)Xl00=l,755.4 lbs. Ans. Problems for Practice. Find the number of pounds of butter which can be made, allowing a loss of .4 per cent of total fat in cream. Test of Fat in Cream lbs. cream. butter. Butter lbs . 1. 2,240 lbs. 30%. 80% Ans. 836.65 lbs. 2. 3,250 lbs. 25% 83% Ans. 976.7 lbs. 3. 3,250 lbs. 25% 80% Ans. 1011. lbs. 4. 5,600 lbs. 30% 82% Ans. 2040.5 lbs. 5. 5,600 lbs. 30%. 81% Ans. 2065.7 lbs. 76. To find the approximate per cent of fat and moisture in butter when the fat in cream and butter are known; 31/2% being allowed for salt and casein. Problem: Cream contains 800 lbs. of butter fat and made 970 lbs. of butter. What is the approxi- mate per cent of fat and of moisture in the butter? Rule I. Divide the fat pounds by the butter pounds; multiply the quotient by 100. The result is the per cent of fat in the butter. Rule II. To the per cent of fat in the butter add 3%%; subtract this sum from 100; the remainder CREAMEEY PROBLEMS. 291 is the approximate per cent of moisture in the butter. Solution: (800^970) X 100=82.47% fat in butter. 82.47+3.5=85.97; 100—85.97=14.03% moisture. Explanation: When 800 lbs. of fat are made into 970 lbs. of butter we have ^^Vg^o of 100 lbs. fat in every 100 lbs. of butter. The moisture must equal the difference between fat in butter plus 3^^ and 100. Problems for Practice. Find the per cent of fat and moisture in butter in the following : Fat in cream. Butter. Fat in butter. Moisture, 1. 2. 3. 4. 5. 850 lbs. 1,500 lbs. 2,180 lbs. 3,670 lbs. 10,500 lbs. 1,000 lbs. 1,850 lbs. 2,560 lbs. 4,500 lbs. 12,500 lbs. Ans. 85. % Ans. 81.08% ^Tis. 85.15% Ans. 81.55% Ans. 84. % 11.5 % 15.42% 11.35% 14.95% 12.5 % 77. Promiscuous problems. 1. A creamery receives 20,000 lbs. of 4% milk daily; losses in separating are 1%% of the total fat; losses in the buttermilk are %% of the total fat. How many pounds of butter with 80, 81, 82 or 83% fat can be made from the milk? 80%=985 lbs., 81% =972.7 lbs., 82%=960.9 lbs., 83%=949 lbs. Ans. 2. (a) The total milk received is 15,000 lbs. test- ing 4% ; from this milk was made 720 lbs. of butter with 80% fat. Find the loss of butter fat in pounds and in per cent. (b) What is the test of the skim milk and butter- milk when skim milk is 80% of the whole milk, and the buttermilk is 75% of the cream? % of total fat 292 MODERN BUTTER MAKING. lost was lost in skim milk and % was lost in butter- milk. Ans. to (a) : Butter fat lost 24 lbs. ; butter fat lost 4%. Ans. to (b) : Skim milk test .13% ; butter- milk test .35%. 3. (a) A hand separator creamery received in one day 25,000 lbs. of cream from five receiving stations, each shipping 5,000 lbs. of 30% cream, ac- cordiog to their test. When cream was tested at the creamery it was found that three stations were 2% short of total butter fat in their cream and two stations were 3% short, (a) What is average test of cream at creamery? (b) How many pounds of butter fat is lost? Ans. (a) 29.28; (b) 180 lbs. (b) Suppose the butter made from fat in above cream contained 83% fat, (a) how many more pounds of butter could be made from it if it contained 81% fat; (b) what would be the gain in pounds of butter in one year of 300 days, (c) and the value at 30c per pound? Ans. to (b) : a— 208 lbs., b— 62,400 lbs., c-^18,720. CHAPTER V. Discussing Comparative Reading of Cream Test Bottles. Note. — ^Por convenience in illustrating the per cent on the graduation is numbered from top down, instead of the usual way, from the bottom up. 78. Basis af camparison. Assuming that the read- ing of the actual fat column of any cream test bottle is .2 per cent lower than the actual per cent of fat in cream, due to .2 per cent of fat remaining in the bulb of the bottle ; we will take the method of read- ing the milk test bottle as a standard for comparison. The average creameryman reads the tests at about 130° F. The meniscus is about .2 per cent on the reading of the test, which is equal to the .2 per cent of fat left in the bulb of the test bottle. 79. Camparing the Reading of 30 per cent, 9 in. cream bottle with a milk test bottle. Fig. I. The average depth of the meniscus of the 30 per cent 9 in. cream test bottle. Fig. II, is between .4 — .5 per cent. Reading this bottle to the extreme top of the fat column, the reading will be from .2 to .3 per cent too high. The curvature of the bottom of the fat column is greater than the curvature of the fat column in the milk test bottle. Fig. I. By reading the fat column in the cream test bottle. Fig. II., from the extreme bottom to the extreme top, the reading will be about A per cent too high. According to the variation in the even- ness of the bottom curve, c, the reading should be 294 MODEEN BUTTEE MAKING. done from the extreme bottom line, d, to almost the extreme bottom of meniscus, b. Eead from d to f. In reading from d to f, the upper part of the menis- cus is cut off to allow the fat making up the sides ^^^SIj2^ CSr -^ Fig. I e- — ^4 g=^ a Fian. ■ffl& Note.— Figs. II, III, IV, V and VI are part of neck of cream bottle enlarged two times. of the meniscus to fill up the hollowness below line f. The .2 per cent of fat left in the bottle will displace the curvature at the bottom of the fat column — d, c. The meniscus occupies .4 per cent on the reading. READING TEST BOTTLES. 295 This bottle, due to the small size of the meniscus, is the best bottle for the inexperienced creameryman. Even if the dividers should slip a little, the error arising from this would not be great, because the graduation is in .2 per cent, and 1 per cent on the graduation takes up quite a space on the bottle. By weighing out 9 grams into bottle shown in Fig. Ill, an error made is increased by two, and when an error is made in reading the test of the sample the error made in weighing is multiplied by 4. 80. Comparing a. 9 gram Fig. IV., 50 per cent cream test bottle with an 18 gram, 30 per cent cream test bottle, Fig. II. The 30 per cent, 9 inch cream bottle. Fig. II, is graduated into .2 per cent, while the 50 per cent, 6 inch bottle. Fig. Ill, is graduated into .5 per cent. The meniscus of the bottle, Fig. Ill, is about 1.8 per cent. Reading this bottle from Fralll the extreme bottom to the extreme top, the reading is about 2 per cent too high, as compared with Fig. II, the reading of which is about .3 per cent too high. The difference here is due only to the differ- 296 MODEEN BUTTEE MAKING. ence in the graduation of the bottle, the size of neck and the grams used. It will be noticed that the space between the markings on the bottle, Fig. Ill, are about three times as close as the markings on bottle, Fig. II. This closeness of graduations in- creases errors in reading, by three. The closer the markings of spaces occupying 1 per cent on the reading, the greater are the chances of errors aris- ing through not being able to get a perfectly cor- rect reading. From this analysis it seems that the bottle shown in Fig. III. is the most difficult to read correctly. The safest way to read this bottle is to read from the extreme bottom, a, to the extreme top, c, of the fat column, and subtract on the aver- age about 2 per cent from the reading. 1. per cent occupies ^/i8 inch on the 50 per cent, 6 inch, 9 gram bottle. Fig. Ill, and 1. per cent occupies 4 inch on the 30 per cent, 9 inch, 18 gram bottle. 81. Comparing a 55 per cent, 9 inch, Fig. IV., 18 gram cream test bottle with a 50 per cent, 6 inch, Fig. Ill, and a 30 per cent, 9 inch, Fig. II, bottle. Fig. IV, 55 per cent, 9 inch, 18 gram cream test bottle is graduated into I/2 per cent divisions; each division measuring in width ^/gg of an inch. Each V23 inch on the neck of the bottle means .5 per cent fat. 1 per cent of fat occupies about V12 i^ich space. In bottle shown in Fig. II. 1 per cent occu- pies i of an inch space. The per cent spaces, on a 30 per cent, 9 inch, cream bottle. Fig. II, are twice as wide as those on bottle shown in Fig. IV, and at the same time represent the same per cent of fat. Any error made in using bottle shown in Fig. IV is EEADINa TEST BOTTLES. 297 twice as great as the same error made when using bottle shown in Fig. II. An error made in using bottle shown in Fig. Ill is 11/2 times as great as the ■/o$ Fi&El same error made in using bottle shown in Fig. IV. These errors used for illustration may be due to either over or under reading, caused by an over- sight, slipping of the dividers, or any foreign sub- stance which may have found its way unnoticed in- to the fat column. The meniscus in Fig. IV. occupies about .8 per cent on the reading and in extreme cases 1 per cent. In- cluding the curvature at the bottom, the reading between the extreme ends of the fat column, a-b, is .8 per cent to 1 per cent too high. For practical purposes, read from a to b and subtract nearly 1 per 298 MODEEN BUTTEE MAKING. cent. This will come nearer to the right reading than reading from a to c or from e to d (and allowing for the meniscus) due to difficulty in locating these places on the graduation. The curvature of the bot- tom of the column in cream tests is rounded enough to allow for the .2 per cent left in the test bottle. Therefore all subtracting should be done from the top — the space occupied by the meniscus. 82. Comparing a 50 per cent, 6 inch, 18 gram cream test bottle with a 30 per cent (Fig. II.), a 50 per cent (Fig. rri), and a 55 per cent (Fig. IV) bottle. Fig. V shows a 50 per cent cream bottle gradu- ated into 1 per cent. There are 16.3 per cent per inch in the graduation. The graduated part FiqV of neck is about S^ inch long. The diameter of the inside of neck is % inch. This is too wide for correct reading, because the bottom of the fat column is not always even. Sometimes the bottom of the fat column curves upward, or is slightly hollow (e), or irregu- READING TEST BOTTLES 299 lar. Due to these unavoidable irregularities this bottle should be used in the following manner if it must be used: Read from the extreme bottom (a) of the fat column to the bottom of the meniscus (b), or from (a) to half way between (b) and (d). Do not add or subtract anything in practical work. When the bottom of the fat column is smooth and well defined, and the meniscus is clear and well de- fined, half of the meniscus may be included in the reading (b-d). That is, read from (a) to (d). When the bottom of the fat column is irregular and the meniscus not well defined, read from (a) nearly to (d), between (b) and (d). Since the graduations are divided into whole per cents and the neck is so wide, the bottle is not at all desirable for accurate work. For convenience in illustrating, the Fig. V. shows graduations in .5 per cent instead of 1 per cent, the way the bottle is actually graduated. Since the cream bottle in Fig. Y. is only graduated into 1 per cent, and 1 per cent on this bottle occupies only about iV of an inch, it is plain that a slight error in reading this bottle would make a great difference in the results. 83. Comparing a 30 per cent, 6 inch, 18 gram, cream test bottle with bottles shown in Figs. II., III., IV., V. The 30 per cent, 6 inch, 18 gram bot- tle. Fig. VI., is graduated in % per cent and 12 per cent occupies a space of 1 inch. Therefore, .5 per cent occupies V24 inch, which is about the same as bottle in Fig. IV. This is a very good bottle. 300 MODEEN BUTTER MAKING. unless cream tests more than 30 per cent when an 18 gram sample must be used. When the scales are sensitive and the sajnple well mixed and correctly weighed, it may be advisable to weigh less than 18 grams of cream for testing, but for the average creameryman, it is not advisable to weigh out less than 18 grams of cream. ■^ FigH -^^'% 84. Errors arise from weighing out 9 grams (as the result must be multiplied by two) and errors are further incurred by weighing cream on a scale not sensitive enough, where a drop or two too much would raise the test considerably. If 18 grams are used any small error is not multiplied. The cream test bottle Pig. VI. should be read either from a to d or from e to c, or half way between d and c. The part between b and c is the meniscus and occupies about .7 per cent space on the graduations. READING TEST BOTTLES 301 85. Comparative length of the graduated part of the neck of cream test bottles. TABLE XIII. Comparative Length of the Graduated Part of the Neck of Cream Test Bottles. Figures II m IV V VI Grams basis on which bottles are graduated 18 9 18 18 18 Per cent cream bottle 30% 50% 55% 50% 30% Size of bottle— 9 in 6 in Gin 6 in 6 in Length of graduation 5% in 2% in 413/19 In SV" in 2% in Graduated % .2% .5% .5% .1% .5% Number of per cent per inch- 578% 18% 11.4% 16.3% 12% Inside diameter of neck— 9/32 in 23/6* in 25/«* in %in. 13/32 in Space meniscus occupies % — .3— .4 1^-1.8 .7-1. 1.-1.6 .5-.7 From the above table as well as from the foregoing discussion it will be seen that the larger the space occupied by 1 per cent on the test bottle, the less chance there is for errors. When 1 per cent on the reading of the test bottle takes up only V^s of an inch, and 5 per cent takes up only Y^g of an inch, one can readily understand that the chances are greater than with a bottle on which 1 per cent takes up about ^/e of an inch on the reading of the test bottle, or 5 per cent takes up about ^/q of an inch, or nearly one inch. 86. Reading of cream tests. We must not forget that in practical work there must be a method for reading tests, which can be quickly as well as accurately performed. In Bulle- tin No. 58, U. S. Department of Agriculture, we find 302 MODERN BUTTER MAKINO. a short rule to be used to assist in reading cream tests accurately. It is as follows: ''Read the test from the extreme top to bottom of fat column; de- duct from this reading four-fifths of the depth of the meniscus and add .2 per cent to the results." This rule is short, but the computations necessary- may prove too much for the ordinary creamery opera- tor. Since we know that the fat column in all cream test bottles is curved downward at the bottom, enough to cause a hollow on each side of about .1 per cent, we can safely say that the .2 per cent of fat supposed to remain in the bulb of the bottle will be sufficient to fill this space. The fat column in bottle Pig. II., 30 per cent, 9 inch cream bottle, is practi- cally straight at the bottom and therefore this would not apply to this particular bottle. Knowing about how much the meniscus of each cream test bottle occupies, and how much more easily the reading of the test from the extreme bottom to the extreme top of the fat column can be done, why not read cream tests in the following manner: Rule. Read any cream test from the extreme bot- tom to the extreme top of the meniscus, and sub- tract from this reading nearly the whole per cent of the meniscus. 87. Illustrating how to read cream tests. The above readings correspond very closely with reading taken from a to d in Fig. VI, a to d in Fig. V, a to f in Fig. Ill, a to c in Fig. IV, and d to f in Fig. II. Inaccurate sampling and weighing of cream samples, as well as incorrect whirling of bottles and reading tests at improper temperatures. READING TEST BOTTLES 303 are the cause of as much inaccuracy in testing as may arise from the use of improper cream test bot- tles. It is, however, very important in testing cream, to have bottles, the graduations of which are not placed closer than 10 to 12, per cent spaces, per inch of graduation. Test bottles that are graduated to carry 6 to 8, per cent spaces, per inch are much to be preferred. Illustrating How to Read Cream Tests. Cream bottle Size Full Reading Average Per cent of meniscus Corrected Reading 30% 9 in. 30% .3% 29.7 30% 6 in. 30% .5% 29.5 9 gram 50% 6 in. 30% 1.5% 28.5 55% 9 in. 30% .7% 29.2 50% 6 in. 30% 1.2% 28.7 88. The most accurate cream test bottles now generally used are the 30 per cent, 18 gram, 6 inch, % inch neck diameter; the 30 per cent, 18 gram, 9 inch, and the 50-55 per cent, 9 inch, 18 gram cream test bottle. The reason why the reading of tests made from the same lot of cream with differently graduated cream test bottles is not always the same is mainly due to inaccurate graduation of the bottle, irregu- larity in the surface of the top and bottom of the fat column and the inability to determine the proper points on the graduation from which to read the tests. Were the fat column clear, with straight top and bottom line, the reading could be accurately done with any cream test bottle. INDEX TO BOOK 11. DAIRY ARITHMETIC CHAPTER I. PERCENTAGE AND DECIMALS. Par. No. Page 1. Notation and numeration 216 2. Expressing the value of a decimal 217 3. Eeading of decimals 218 4. Principles of decimals 219 5. Multiplication of decimals 221 6. Special rules for multiplication of decimals 221 7. Addition of decimals 222 8. Subtraction of decimals - - . 223 9. Division of decimals 224 10. Examples for illustration 224 11. Reducing fractions to decimals 227 12. Reducing decimals to common fractions 227 13. Percentage 228 14. Various ways of expressing per cent 229 CHAPTER 11. THE OVERRUN. 15. The overrun in butter making 232 16. Overrun influenced by market demands 232 17. Definitions and explanations 233 (a) Overrun 233 (b) Per cent of overrun 233 (c) Percentage of overrun - _. 233 18. Cause of overrun 233 19. Variation in overrun in whole milk creameries 234 20. Variations in overrun in hand separator cream cream- eries 234 INDEX 305 Par. No. Page 21. True and false overrun. True overrun _^-.__ 234 22. Market or false overrun 235 23. Overrun based upon market returns 236 24. Overrun based upon composition of butter 236 25. How to find the per cent of butter fat in butter 237 26. Hand separator cream overrun 237 27. Comparison of true overrun 238 28. Market overrun 238 29. Overrun based upon composition of butter 238 30. Comparison of various overruns 239 31. Overrun for a whole milk creamery 240 32. Overrun for a hand separator cream creamery 241 33. Overrun on print butter 242 34. How underreading milk tests affects the results in butter making 243 35. Extension of Table No. VI 244 36. How overreading affects the overrun 244 37. Effect of under reading cream tests 245 38. Table No. X 246 39. Butter fat in milk plus one-sixth equals the amount of butter made 246 40. Effect of overreading cream tests 247 41. Continuation of Table XI 248 42. Main factors affecting overrun 249 CHAPTER III. STANDARDIZATION OF MILK AND CREAM AND BUTTER FAT VALUES. 43. Correct standardization 251 44. Extent of losses - 252 45. Losses on cream 253 46. Problems in standardization 255 47. When whole milk is used 260 48. Standardizing whole milk 261 49. How to use viscogen as a thickening agent 263 50. A few suggestions on the use of viscogen in commer- cial cream - 264 51. Butter fat values 264 52. Problems with explanations 265 53. Comparative values 268 54. The value of butter fat in cream 268 306 MODERN BUTTER MAKING. CHAPTER IV. PROBLEMS RELATING TO THE RECEIVING AND SEPARATING OF MILK. Par No. Page 55. Find the amoimt of butter fat in milk 269 56. Find butter fat losses in skim milk 270 57. Find per cent of cream from milk 271 58. Find per cent of cream from milk when other factors are known 271 59. Find amount of cream from milk 272 60. Find amount of cream when other factors are known. 273 61. Find amount of cream, butter fat losses 1^ per cent- 274 62. Find skim milk lbs. from any quantity of milk 275 63. Find approximate test of cream 276 64. Find approximate average test of skim milk 277 65. Table of relative loss in skim milk 278 66. Promiscuous problems 279 ±>. Problems Pertaining to Cream Ripening. 67. Find lbs. of starter to add to cream 281 68. Knowing per cent of starter added, find lbs 282 69. Find per cent of starter added to cream 283 70. Find acidity of cream after adding starter 284 71. Find acidity of cream before diluting 285 72. Promiscuous problems 286 73. Problems bearing on the manufacture of butter 287 74. Find per cent of fat in buttermilk 288 75. Pounds of butter that can be made 289 76. Find per cent of fat and moisture in butter 290 77. Promiscuous problems . 291 CHAPTER V. DISCUSSING COMPARATIVE READING OF CREAM TEST BOTTLES 78. Basis of comparison 293 79. Comparing the reading of 30% bottle 293 80. Comparing a 9 gram cream bottle . 295 81. Comparing a 55%-18 gram bottle 296 82. Comparing a 50% 6-inch cream bottle 298 83. Comparing a 30% cream bottle 299 84. Errors, how caused 300 85. Comparative graduation of bottles . 301 86. Reading of cream tests 301 87. How to read cream tests 302 88. Most accurate cream bottles 303 INFORMATION TO CREAMERYMEN AND DAIRYMEN. WISCONSIN DAIRY SCHOOL AWARD ' -•■■ »>