THE UNIVERSITY OF ILLINOIS LIBRARY no r NQN CIRCULATING CHECK FOR UNBOUND CIRCUU- UNIVERSITY OF ILLINOIS, Agricultural Experiment Station CHAMPAIGN, NOVEMBER, 1891. BULLETIN NO. 18. DAIRYING EXPERIMENTS. This bulletin contains reports as follows: 1. Tests of dairy cows at the Illinois State Fair, Peoria, and the American Dairy Show, Chicago, 1891. 2. Experiment No. 106. Investigations of Milk Tests. [#] Comparison of Babcock Test with the churn at the American Dairy Show and at the Station. [3] A device for measuring the acid used with the Babcock Test. [c'] A method of marking milk test bottles. 3. Experiment No. 122. Composite Milk Samples Tested for Butter Fat. (Continuation of report in B. 16.) 4. Experiment No. 131. Cream Separation. Test of Methods. Observations on the per cent of butter fat in skim-milk when milk has been set in cans at different depths; also per cent of butter fat in the skim-milk at the bottom, middle and top of the cans. 5. Experiment No. 115. Cream Raising by Dilution. Observations on the rate at which cream rises when the milk has been diluted with water; and as to whether the rising of the cream is hastened by the reduction in temperature or by the dilution of the milk. 17 1 8 BULLETIN NO. 1 8. [November^ STATE FAIR TEST. The Illinois State Board of Agriculture offered prizes for cows whose milk should be tested at the State Fair at Peoria, Sept. 28 to Oct. 2, 1891, and at the Dairy Show in Chicago, Nov. 1 1 to 21, 1891. At the request of the Board, through Mr. S. W.Johns, superintendent of the dairy cattle classes, the milk was tested by the chemist of this Station. At the State Fair the competition was for first and second prizes to cows over three years old, and for like prizes to those under three years old in each of the following breeds: Ayrshire, Hol- stein-Friesian, Jersey, and Shorthorn; also for a sweepstakes pre- mium to the cow exceeding all others in the test. The prizes were awarded to cows producing the most butter fat in the one day's test, made Sept. 29th. The Shorthorn cows were tested for two days in ac- cordance with requirement of the American Shorthorn Breeders' Asso- ciation, which offered a special prize for cows of that breed. The table on pp. 20 and 21 gives the results. In each class the cows are given in order of production of butter fat. The weights of the cows are estimates made in most cases by their owners. No very striking variation in the composition of the milk given by any one cow at different milkings is shown. Some cows gave the richest milk at night, some in the morning. Generally the cows which were milked three times each day gave the richest milk at noon. It is well known that a short test at a fair may not show the average capacity of the cow. AMERICAN DAIRY SHOW TEST. For the Dairy Show, in connection with the Fat Stock Show, the test was required to be for three days. Three cows only competed \ two Brown Swiss and one Devon. The cows were weighed the day before the test began. The Brown Swiss cows were also weighed the day after the test closed. The cow Brienz was 20 Ib. heavier, and the cow Eliza 20 Ib. lighter at the second weighing than at the first. Mr. Bourquin states that the daily ration of each of the Brown Swiss cows, during the test, was about as follows: 24 Ib. mixed grain, made of three parts corn and cob meal, one part ground oats and one part bran; 3 quarts cotton seed meal; 3 quarts linseed meal; 3 pecks carrots. This was fed in three equal feeds daily, with clover hay after each feed. The cows were offered water three times daily. The results of the test are given in the table on p. 19. The performance by the Swiss cow, Brienz, is a remarkable one, both as to milk and butter fat produced. It is not known that it has been equalled in either respect by any other cow tested at a public show. The cows were kept in open stalls, exposed to the sight and hand- ling of visitors. The weather was somewhat unfavorable. MILK TESTS, FAIR AND DAIRY SHOW. T3 Is PQ^ 1 ^G D cL eu i 1 11 IN "o 1 H ** ~ ^ e ^ M O flc ~ ll-kl ffl .s 8." co T3 H a .00 rn 1-1 M IN N C) d o d P - O M 1 d d o" VO M H- 1 s 1 i '3 in in n t/~ .s" '3 00 O in ^ ^ J 0) o 1 o PQ CO ococo ^COCO CD CD -H 4 LO 0) CO a 1 i PQ CD 00 cqcpi> CM CO ! 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M -* 1 Q m <*- N ON H M in, in en 00 M M o , >-, rt rt rt H3 T3 to T3 T3 M N en rt O . 0) ? u > < 20 BULLETIN NO. 1 8. [November ) A Butte at . Milk. > 3-3 Butter fat. Milk. Night. Noon. Morning. Night. Noon. Morning. Approximate weight. Last calf. Age, years. m M m H 0^% Tt- N 00 N T}- odd d d d d d d d d 6 d d d 00 N O> M co co ci co COCOCOCOCOCN f m co 888 CJ O\ O^ O\ H Jo o o o o o o o o o o o o o 00 00 00 00 00 O O H" i-T Ste? till be bi>j^> bb bJo'C "Q. bi oo vo H N CN M M in o ^- ^~ co in >c t^ M : : : : ; ' jer 3 years old. J. H. Packard, New Windsor, Co C. F. Stone, Peabody, Kas Gillett & Son.Rosendale, Wis . . . years old. J. H. Packard, New Windsor, Col W. H. Logan & Son, Seaton, 111. . Gillett & Sons, Rosendale, Wis.. G. A. Stanton, Greenwood, Ind.. old. George Merna, Wyoming, 111.. . George Merna, Wyoming, 111... La Veta Cattle Co., Topeka, Kan Garretson Bros., Pendleton, Ind.. Latimer & Miller, Abingdon, 111.. George Merna, Wyoming 111 La Veta Cattle Co. , Topeka, Kan C. Easthope, Niles, O *>:::: 5 -^ -s ^ K ""*" r>} ... ^ .... <-5 ^ V . . . g . .tg s S rt \~ ' '- S Holstein-Frie. Tirannia Empress Josephine Rijaneta Holstein-Friesian cm Mechtchilde, ad... Vizzer Queen Duchess of Springd Pride of Winnikee. ^ O .S 'g o c/5 75 1891.] MILK TESTS, FAIR AND DAIRY SHOW. 21 cr\O co M | rj- PO PO N CO M W M W O d d d d o' o" o o M M odd *f- t^O wOO d d d S,o mn ? M M PO PO PO N M 00 PO ro M N OOQCOiO ^oddd odd odd 10 lO iO 1C IOIOCJ IOIOUD PO ^ M PO vn TJ- Tt- TJ- TJ- PO N PO ^> PO PO - >- ^ zoo c* c^ ^* O co in N C7> O^ M O M H O O d d d d o 6 ^ N O\ Oi 1 ^- PO fO PO N N M" lOO) ^ n O PO N <* rj- PO PO on *. : : i o ro '.'.'. \ 01 cd od uSvo oo m PO in N O\ N O moo' t^ M M M M . . . . vO ... . . . - M .... in m r^ oo O> "S in C^ 00 C^ in t^ ro d^ cooo" t^ N M HI H id >~,T3 >-, ^_, oS ,M rt 13 E 'S _ _ - G" o" e e T3 T3 0) , \, {2 S . . : : 1 ^ i i JM Shorthorn cows over j ye Arabella Doodle Summa ry Averages fro Holstein-Friesian cows over 3 Holstein-Friesian cows under Jersey cows over 3 years old . Jersey cows under 3 years old Ayrshire cows over 3 years ol( Ayrshire cows under 3 years c Shorthorn cows over 3 years c 22 BULLETIN NO. iS. Experiment No. 106. Investigation of Milk Tests. COMPARISON OF BABCOCK TEST WITH THE CHURN AT THE AMERICAN DAIRY SHOW AND AT THE STATION. The milk given at one milking at 2:30 p. m., November i8th, by the two Brown Swiss cows tested at the Dairy Show at Chicago was taken for churning. The milk weighed 52 Ib. and by test contained 1.971 Ib. butter fat. It was run through a " Baby " hand separator No. 2. Several samples of the skim-milk were taken as it came from the separator, which showed only a trace of butter fat. The cream weighed 10.25 Ib., or 19.7 per cent of the new milk. The tests showed that the cream contained 19.23 per cent butter fat. This cream was ripened for about 24 hours and then churned. The details of the results are given in the table below. During the progress of the Dairy Show a working dairy was in operation. For this thirty cans of milk were received. Wednesday, Nov. 1 8, this milk weighed 2,035.25- Ib. It was put in a large vat, warmed, and thoroughly mixed. The thoroughness of the mixing is illustrated by the fact that tests of four samples showed no variation in RESULTS OBTAINED FROM THE CHURNINGS. Cream from milk of Brown Swiss cows. Weight of cream churned 10.25 Temperature of cream churned 61 F. Temperature of buttermilk 59 F. Time of churning 65 min. Acidity of cream [50 c.c.=i-io normal alkali] 25 . 5 c.c. Weight of buttermilk, Ib 15 Per cent of fat in buttermilk 0.6 Weight of salted butter from churn, Ib 2 1875 Weight of butter fat by test of milk, Ib i .971 Difference 0.2165 Percentage increase of churn over test, or of butter over butter fat in the milk | 11.5 Analysis of butter Water, per cent J 5 4 Butter fat, per cent 77 . 24 Salt, per cent 6.6 Curd, per cent i o . 76 Total 100 . oo Pounds of butter fat in the butter i . 689 Pounds of butter fat in the buttermilk 0.09 Total i . 779 Pounds of butter fat in the milk used, as shown by test i . 97 1 Difference loss or gain in the process. 0.192 Per cent, which loss .or gain was of total butter fat in milk used 9 . 7 Working dairy 6iF. 6iF. 17 min. 37 c.c. 204.5 0.3 104.5 84.46 20.04 23.6 82. 3- 0.85 85.69 0.61 86.30 .46 -1.84 -2.17 MILK TEST COMPARED WITH CHURN. 23 the per cent of butter fat. One sample was taken from the middle of the vat, two from the ends, and one from the first milk drawn from the faucet. The milk contained 4.15 per cent of butter fat, or 84.45 ^ D * m the 2,035.25 Ib. milk. This milk was run through a separator in 65 minutes. The speed of the separator was said to be 6,000 revolutions per minute. Traces only of butter fat were found in four samples of the skim-milk taken during the process of separation. It required 9.8 c.c. of one-tenth nor- mal alkali to make 50 c.c. of the milk neutral. After ripening for 24 hours the cream was churned. Details are given in the table above. The butter obtained from the 52 Ib. of Brown Swiss milk was about 3 oz. more than the butter fat in the same milk, as indicated by the tests of the new milk. The butter obtained from the 2,03^.25 Ib. of milk used in the working dairy was 20 Ib. more than the butter fat shown by tests of the milk. This is an increase of the churn over the test of 11.5 and 23.6 per cent respectively. From analyses of the butters, with the records of weights of butter and buttermilk, the account kept with the Brown wSwiss milk shows a loss of 0.19 Ib. butter fat, or 9.7 per cent of the total weight of but- ter fat in the milk started with. Although this is not the finest working that can be done, so small a quantity could easily be lost by adhering to the dairy utensils of processes through which the milk passes to make butter. The account kept with the 2,035.25 Ib. of milk in the work- ing dairy shows an increase of 1.84 Ib. of butter fat over the total quantity in the fresh milk as tested. This figurative creation of butter fat in excess of what there was in the milk is probably due to the water that the 13 wooden boxes absorbed after they were weighed. The helper who packed the butter into the boxes from the churn had weighed the dry boxes, then dipped each one into cold water, filled it with butter, and from the total weight subtracted the weight of the dry box so that the water absorbed by the boxes appears as weight of but- ter. The salt added to the butter from the Brown Swiss milk was not weighed, but estimated by the helper and the analysis of the butter shows an excessive quantity. A comparison of the test and the churn has been made at the dairy of this Station, together with an analysis of the butter, and the accounts balanced well. This work, except the last two churnings, was done by one person, and the dairy utensils used were carefully cleaned to pre- vent any loss of butter fat in the process. The milk used was from one Jersey cow about one month after calving. In four trials the milk was set in Cooley cans with bottom faucet. Another trial [the third in the tables] was made by setting the milk in shallow pans, which were the common kind used for this purpose, but with a hole at one side near the bottom. This hole was closed with a cork until time to skim the milk, when, by pulling the cork, the skim milk was drawn off till the cream fell to the hole and then the cork was replaced. 2 4 BULLETIN NO. iS. [ November, RECORD OF THE WEIGHTS AND TESTS OF THE WHOLE MILK AND SKIM-MILK. Milk set in Whole milk. Cooley cans Skim-milk Date. in a refriger- ator. Tem- Butter fat. Butter fat. Pounds. per cent. pounds. perature 45 to 48 F. Pounds. per cent. pounds. First trial Oct, 16, a. m. 12. 18 3-9 -475 24 hours 9-5 0.2 0.019 Oct. 16, p. m. 10.18 5-8 059 12 " 7-93 1.2 0.095 Oct. 17, a. m. 11.64 4-i 0-479 48 9-43 O.I 0.009 Oct. 19, a. m. n-43 3-6 0.411 24 9-25 0.2 0.018 Total I Q55 O 141 Second trial Oct. 19, p. m. 10.5 5-8 0.609 36 hours 8.18 0.4 0.0327 Oct. 20, a. m. 12 5-3 0.636 24 " 9.12 0-4 0.0364 Oct. 20, p. m. IO.2I 5-2 0.531 12 9.12 o-4 0.0365 Oct. 21, a. m. 12.56 4-7 0.589 48 " 10 0.2 0.02 Total 2.365 0.1256 Third trial, milk set in shallow fans, temperature 45 to 48 F. Noy, 5, a. m. . 9-75 3-7 0.36075 24 hours 8-437 0.05 0.004218 Nov. 5, p. m. . 8-5 4.6 0.391 12 " 7.18 0.4 0.02872 Nov. 6, a. m. . 9.84 4-i 0.40359 24 " 8.312 O.I 0.008312 Nov. 6, p. m. . 8.56 5-2 0.44525 12 " 6.75 0.2 0.0135 Total 1.60059 0.05475 Fourth trial Oct. 31, p. m. 8.18 4 0.3275 36 hours 6-375 0.2 0.01275 Nov. i, a. m. . 9.69 3-9 0,3778 24 " 7-75 0.2 0.0155 Nov. i, p. m. . 7-51 5 0-375 12 5-593 o-7 0.03916 Nov. 2, a. m. . 10.37 5-2 0-5395 2 4 7-75 O.2 0.0155 Total 1.6198 0.08291 Fifth trial Nov. 8, p. m . 8-93 5 0.4468 36 hours 6-437 0.2 O.CI287 Nov. 3, a. m . 9.88 4.6 0.4542 24 " 7-312 O.I 0.00731 Nov. 4, a. m . 11.25 4-4 0.492 48 " 9 O.I 0.009 Nov. 4, p. m . 7-94 5-7 0.4524 12 5-562 I 0.0556 Total 1.8454 0.08478 The results from the five churnings (next page) illustrate a gradual change from a loss to a profit by attention to the proper temperature and acidity of the cream churned. In the first trial the temperature of the cream was too high and the cream was not sour enough. This caused a loss of 5.3 per cent of butter fat in the buttermilk; and the butter obtained was 10 per cent less than the total quantity of butter fat in the milk used. A test of the buttermilk is a good guide for judging of the thoroughness of the churning, and in the above record it can be seen that the per cent of butter fat in the buttermilk gradually decreases from the first to the fifth trial, in which the cream was churned in about proper condition as to temperature and acidity, giving a butter- milk which contained only o.i per cent butter fat and a weight of but- MILK TEST COMPARED WITH CHURN. RESULTS OBTAINED FROM THE CHURNINGS. Temperature of cream churned, F. . . . Temperature of buttermilk F First trial. Second trial. Third trial. Fourth trial. Fifth trial. 68 64 15 I3C.C. 8 5-3 i-75 1-955 80 74 3 35-5C.C. 8.56 4-9 2-34 2.365 66 62 10 28.5C.C. 3.875 1.25 1.8125 i. 6006 62 60 7 36. 5 c.c. 6 0-35 1.84 1.619 58 58 20 4i.6c.c. 6.78 0. I 2.156 1.848 Time of churning, minutes Acidity of buttermilk [50 c.c.= i-io normal alkali] . . Weight of buttermilk, Ib . . Per cent of fat in buttermilk Weight of unsalted butter from churn. . Weight of butter fat by test of milk. . . Difference lessor gain in the process Per cent which loss or gain was of total butter fat in milk used 0.205 10.4 19.56 78.94 i-5 0.025 1.06 21.33 77- 1.67 -(-0.2119 +13.24 15.66 82.54 1.8 -(-0.221 +13.64 14-95 83.27 i.78 +0.308 +16.65 15 83.2 1.8 Analysis of butter Water, per cent Butter fat, per cent Curd per cent Total 100.00 1.381 0.424 0.141 IOO.OO I. 8018 0.4194 0.1256 IOO.OO 1.496 0.0484 0.0547 IOO.OO 1.535 0.021 0.083 IOO.OO 1.7939 o . 0067 0.0847 Pounds of butter fat in in the butter. . Pounds of butter fat in the buttermilk. Pounds of butter fat in skim-milk Total 1.946 1.955 2.3470 2.365 1.5991 I. 6006 1.639 I.6I9 1.8853 1.848 Pounds of butter fat in the milk used, as shown by test Difference loss or gain in the process . Per cent, which loss or gain was of total butter fat in milk used . . o . 009 -0.46 0.018 0.7 0.0015 -0.1 +0.02 + 1.23 +0.037 +2. ter 16 per cent greater than the butter fat in the original milk. The butter was weighed and a portion taken for analysis before it had been worked. This accounts for the large per cent of curd found by the analysis. The cream used in these five churnings was separated from the milk in different ways. All the milk was set at a temperature of 45 to 48 F., either in Cooley cans with bottom faucets, or in shal- low pans. The cream was not skimmed from the milk in the shallow pans, but the skim-milk was drawn off at the bottom of the can, as before described. 26 BULLETIN NO. iS. of AUTOMATIC PIPETTE. This figure illustrates a device for measur- ing the acid used with the Babcock milk test. By this arrangement the glass automatic pipette can be put through the cork of any bottle of acid, which is also kept closed, thus preventing any change in the strength of the acid. A system of valves is so arranged in the rubber bulbs E, F, that by squeezing F in the hand air is forced through the tube H into the bottle of acid M. This pressure of air forces the acid through the tube K up into the pipette D until it overflows at B; then by turning the cock so that c and d change places the connec- tion is closed between the bottle and pipette and opened from the pipette out through the tube A from which the measured acid is delivered into the test bottle. The end of the tube H inside the bottle should not touch the acid, but the end tube K should always be in it. This should be of stout glass with an in- side diameter of 3-16 in., the holes hrough the glass cock should be j^ in., and the delivery tube A, from the pipette to the test bottle, should have an inside diameter of i^ in. and an outside diameter of 7-32 in. MARKING TEST BOTTLES. The common practice now is to mark milk test bottles with a num- bered ring or band of copper around the neck of the bottles. In keeping up the supply of test bottles it often happens that new ones have the same numbers as those already in use. Two bottles with the same number may cause confusion and guess work, if two different samples of milk are tested in them at the same time. The enlarged end of the the neck of the test bottle often' breaks off, and< though the break may not be suf- ] COMPOSITE MILK SAMPLES. 27 ficient to prevent using the bottle, the copper band easily slips off and is lost. A simple and efficient way of marking test bottles is to grind a label on them with a file. Wet with water a flat side of a three-cornered file and use the wet side of the file. File a space about one- fourth inch square at any convenient place on the test bottle, thus making the smooth surface of the glass rough and on this ground label mark num- bers with a lead pencil. A good place to file the label is either above or below the graduations on the neck of the test bottle. Experiment No. 122. Composite Milk Samples tested for Butter Fat. A report was made in bulletin No. 16 of this Station of trials at the creamery of H. B. Gurler, DeKalb, and at the Station dairy of a method of using composite samples in testing milk. The method of collecting the samples was first described by Professor Patrick in bul- letin No. 9 of the Iowa Station. The formula tested in the trials made at DeKalb had been sent by Professor Patrick to Mr. Gurler at his re- quest. As pointed out by Professor Patrick an objection to his method is that the preservative used is a violent poison. To avoid this objection a comparison was made of his method with one suggested by the writer, in which the milk was not poisoned but collected for a week and al- lowed to sour. By adding to a pint of the sour milk about one-half a teaspoonful of "powdered lye" and mixing carefully, it was demon- strated that composite samples of milk could be accurately tested for butter fat without the use of corrosive sublimate. This use of "powdered lye" has proved very practical and satis- factory in a number of creameries during the past six months and is now in constant use by them. It has been found to be advantageous to add the lye to the milk the night before the test is to be made, and in not too great quantity. Adding too much lye makes the milk stringy or clotted. When small lumps of curd are slow in breaking up, a more complete mixing is obtained by setting the jar of milk into warm water at about i4oF. Mr. H. B. Gurler, DeKalb, 111., contributes the following state- ments and figures obtained by his use of the methods : " I am satisfied that the use of lye in the weekly composite samples puts them in condition to give a correct sample for testing. As the weather gets cooler we use less of the lye, and there is more need of warming the jars containing the composite samples, as the cream is liable to adhere to the sides of the jars if lye is not used and they are not warmed. On the whole we are very much pleased with the use of the lye. "The following table gives the tests or per cenJt^. of butter fat in the weekly composite samples of milk brought to the creamery by twenty patrons during October. BULLETIN NO. l8. BUTTER FAT SHOWN BY WEEKLY COMPOSITE TESTS, PER CENTS. No. of Patron Week Ending October JNo. of Patron Week Ending October 2d gth i7th 24th 3oth 2d gth iyth 24th 3oth ii 39 3.7 3 5 3-4 3-2 2 3.6 3-3 3-6 3-7 3-5 12 3.6 3-7 3-6 34 3-4 3 3-6 3-5 36 3-7 3-7 13 39 3-7 3-8 4 3-8 4 3-6 3-5 4 4 4-2 14 4 3-9 4 4 4.1 5 3-8 3-6 3-6 3-6 3-6 15 3-7 3-8 4.2 4 4-i 6 3-9 3-6 4 4- 1 3-9 16 4 3-6 3-8 4 4-i 7 3-8 3-8 3-8 3-4 3-6 17 3-6 3-6 3-4 3-6 37 8 4-4 3C 4.8 ? 6 4.4 3 A 4 o 8 3-9 18 3-6 4 4 3-8 3-6 10 4 4-3 3-8 4 4-4 x y 20 3-6 3-6 3-6 4 3-8 "Some of the variations I can account for. No. 1 1, for instance, had a steady increase in milk from fresh heifers. Some had a decrease from their cows drying off. In the summer months when the conditions of the different dairies were more uniform, the tests ran with a surprising uniformity." Experiment No. iji. Cream Separation, Test of Methods. A number of trials were made to observe the completeness of the cream separation after the milk had been set in Cooley cans, temper- ature 45 to 48F., 12, 24, 36, and 48 hours. Tests for butter fat were also made of the skim-milk in the bottom and the middle of the can, and of that last drawn off. The results show that cream is often lost if the skim-milk is drawn off nearer than one inch from the bottom of the cream. The variation in the tests given in the table on p. 29 under the column headed "last skim-milk" shows the necessity of caution in skimming close to the cream. Drawing off the skim-milk to within one inch of the bottom of cream can be done without loss of cream, if the faucet is set so that the skim-milk does not stop running until it has reached the point where you wish it to stop; repeated opening and closing of the faucet has a tendency to mix the cream so that it flows out with the skim-milk. The summary of this table shows that when the milk of this cow was set in cans to the depth of ten inches the most butter fat was ob- tained in the cream when the milk had been set 48 hours. This was not much better than setting the milk 24 hours, but considerably better than setting 12 hours. An average of 2.4 per cent of the total butter fat in the new milk was lost in the skim-milk when skimmed after 48 hours standing; 4.05 per cent after 36 hours; 3.7, after 24 hours; and 12.87, a ft er !2 hours. One trial of separating the cream by diluting the milk with an equal volume of water, showed that 17.2 per cent of the total butter fat was lost in the skim-milk when skimmed after 2 h. standing. The re- sults obtained from setting the milk in shallow pans showed the most complete separation of cream in this trial. Only 1.62 per cent of the total butter fat of the milk was lost in the skim-milk after standing 24 h., and 5.18 per cent after standing 12 h. CREAM SEPARATOR. More uniformly complete separations of cream than any of the above can be obtained by using a "Baby" hand separator, which we have repeatedly tested, obtaining skim-milk with less than o. I per cent butter fat. RECORD OF THE WEIGHTS AND TESTS OF THE WHOLE MILK AND SKIM-MILK. New Per cent butter fat in Per cent of tota but- Date. milk set. Milk Skim-milk drawn ter fat of new milk Ib. used. Bottom. Middle. | Last. | Total. left in skim-milk. Milk skimmed after standing 12 hours. Oct. 16 10.18 5-8 0.6 0.8 2 1.2 15.76 ) Nov. i 7-5 5 0.4 0.6 0.7 0.7 IO -55 r 12 87 Nov. 4 7-93 5-7 0-5 0.8 3-9 I 12-3 ) Nov. 5 *8. 5 4.6 O.I O.2 1-9 0.4 *7-34 (. - T o Nov. 6 *8.56 5-2 0.2 0-3 0-5 0.2 *3-3 i" Milk skimmed after standing 24. hours. Oct. 16 12.22 3-9 O o-5 0.2 3-9 1 Oct. 19 11.43 OCt. 20 12 3-6 5-3 O.I 0.3 1.9 0.7 0.2 0.4 4.38 I 5-34 I Nov. i 9.68 3-9 0.2 o-3 0.3 0.2 4.1 \ 3-7. Nov. 2 10-37 5-2 2.2 O.2 2.87 | Nov. 3 9.87 4.0 0.4 O.I 1.6 J Nov. 5 *9-75 3-7 O 1.4 0.05 Nov. 6 O.2 0.4 O.I *2.o6 1 x ' 62 Milk skimmed after standing 36 hours. Oct. 19 Oct. 31 Nov. 2 10.5 10.18 8-93 5-8 4 5 o o o 0.2 O.I O.I 6.6 0.8 2.1 0.4 0.2 0.2 5-37 3-9 \ 4-05 2.88 ) Milk Oct. 17 Oct. 21 Nov. 4 skimmed 11.68 12.59 11.25 ifter stanc 4.1 4-7 4.4 iing 4.8 ho o o urs. o o O.I 0.4 1.8 1.6 O.I O.2 O.I 3-4 [ 2.4 1.81 \ Milk diluted with an equal -weight of water and skimmed after standing 2 hours. Nov. 7 | 9.62 | 4.9 [ 0.4 [ 0.5 | 0.5 | 0.5 | 17.2 SUMMARY PER CENT OF THE TOTAL BUTTER FAT IN THE MILK LEFT IN THE SKIM-MILK Milk set in cans, depth of milk 10 in. Milk set in shallow pans. Diluted with one- half water. Time of setting, h. Per cent of total 12 12.87 24 3-7 36 4-05 48 2-4 12 5.18 24 1.62 2 17.2 *Shallow pan, milk 3 inches deep. MlLK SET IN SHALLOW PANS 3 IN. DEEP AND IN BOTTLES 6 AND 9 IN. DEEP. No. trial i 1 >j Manner of setting. Temp. F. of milk when Per cent of butter fat in Set. After i h. After 2 h. Milk used. Skim-milk after standing i h. 2 h. 3 h. 6 h. 9 h. 24h. Shallow pan, depth 3 in 95 95 73 97 Q7 82 7 1 85 77 70 79 3-3 3-3 3-3 2.9 2.9 2.9 3-45 3-45 3-45 2.9 2-5 2.7 0.6 2-4 2.8 0-5 1.9 2-3 0.4 2 2-3 0. 4 2 2-4 0.4 i-5 2.1 0.25 1.6 2 0-3 1.6 2.2 0-3 0.8 M O.I i i-5 0.15 i 1.6 O.I 0.6 0.9 0.05 0.6 1.2 O.05 0.7 1.2 0.05 O.I 0.15 0-5 0. 4 0.9 Bottle, depth 6 in Shallow pan, half water, 3 in. Shallow pan depth 3 in Bottle, depth, 9 in Pan, half water, 3 in 75 96 96 76 72 85 86 74 72 82 82 74 Shallow pan, depth 3 in Bottle depth 9 in Pan, half water, 3 in . ... BULLETIN NO. l8. [November, During the hot weather in July a comparison was made of the rate at which cream would rise when the milk was 3, 6, and 9 in. deep. A mixture of milk from several cows was used and it was set in a room where the temperature was about 7oF. In each trial the cream rose faster and more completely in the shallow pans 3 in. deep than when set in bottles 6 or 9 in. deep. See foregoing table for results. Experiment No. 115. Cream Raising by Dilution. The observations here recorded include a comparison of the rate at which cream rises in hot weather, when the milk of different cows is diluted with an equal volume of water. The benefits of this practice are supposed to be obtained by dairies which do not have ice or a cool place in which to set milk, and where in hot, muggy weather the milk sours before all the cream rises. Under such circumstances it has been suggested that the cream can be separated at once, by adding cold watf r to the new milk. EQUAL PARTS NEW MILK AND WATER. Temperature, F. Per cent, of cream Per cent of butter fat in Dairy Milk Water Diluted milk Milk used. Diluted skim-milk after When set. After 2h. ih. ah. 6h. 9h. Cow No. i July i 2 3 9 10 ii 74 77 73 72 73 75 88 98 98 99 99 99 54 60 59 58 58 59 68 76 7 6 73 74 76 7-3 1 .1 0.4 0-5 0-5 o.5 0-5 0.4 0.05 0.2 0.15 7-3 7-3 7-4 7-4 7-4 5-8 5-6 5-9 5-4 6.3 1.2 1-3 i-7 1-7 i-5 74 74 74 i-3 1.2 1-3 0.6 0.8 Cow No. 2 July i 2 3 74 77 73 72 73 75 88 98 98 99 99 99 54 60 59 58 58 59 66 75 76 74 75 76 66 75 76 75 76 77 7.5 7-3 7-3 5-9 59 5-9 0.3 0.8 0.7 O.2 0-3 Cow No. 3 July 9 10 n 75 75 75 3-5 2.9 3-2 0.6 -7 0.6 0-3 0.7 0.6 0.8 0.9 0.5 0.5 0.5 0.2 0.2 0.15 0.15 0. 4 0-35 0.2 O.I Cow No. 4 July i 2 3 9 10 ii 74 77 73 72 73 75 88 98 98 99 99 99 54 60 59 5 8 , 58 59 75 75 75 6 4-5 4-5 5-9 5-9 5-9 'z's ' 2.8 2-9 2.6 3 0.4 0.5 2 0.3 Cow No. 5 July i 2 3 74 77 73 88 98 98 54 60 59 66 74 76 5-9 4-4 4-4 3-4 3 -4 0.8 0.7 0.15 0.3 0.25 Mixed milk, July i Cows i, 2, 4, 5. 2 3 74 77 73 88 98 98 54 60 59 68 75 76 7-4 5-9 5-9 V.s" 3-45 0.35 0.6 -7 0.2 0.25 0.35 Mixed milk, July 9 Cows i, 3, 4. 10 ii 72 73 75 98 98 99 58 58 59 73 75 76 75 75 75 . 7-4 7 4 7-4 3-3 2.9 3-45 0.6 0.65 0.6 0.4 0.4 0.4 0.15 0.3 0-3 0. I 0.2 0.2 CREAM RAISING BY DILUTION. The following trials were made to demonstrate how thoroughly the cream can be separated in this way, and what results would be obtained with the milk of 'different cows. About one-half a pint of new milk was mixed with the same quantity of water. The mixture was put into wide mouthed glass bottles with a faucet at the bottom by which portions of skim-milk were drawn off for testing. The mixture filled the bottles to a depth of 4 inches. The temperature of the milk was about 98 F. when mixed with water of about 58 F. The temperature of the mixture was about 75 F., and it was kept in a room where the temperature ranged from 66 to 76F. A test was made of the skim- milk after the mixture had stood i, 2-, 6, and 9 hours. The details are given in the foregoing table: The milk used, 250 c.c., was carefully measured each time. A calculation has been made to show the per cent of the total butter fat of the milk which was left in the skim-milk. PERCENTAGE OF TOTAL BUTTER FAT LEFT IN THE SKIM-MILK. Milk set. i hour. 2 hours. 6 hours. 9 hours. Cow No. i, av. of six trials .... 3, av. of three trials. . 4, av. of six trials. . . . 5, av of three trials . 46 35-5 5o A-3. 35-5 28.7 33 22.4 14.7 16.8 14.9 10.4 17-3 is 8 Mixture i av of three trials 31 5 I c 2. av. of three trials. . 34-7 23-3 13.9 10.4 Average 40.1 30.1 17 *4 These tables show that there was quite a variation in the per cent, of butter fat found in the diluted skim-milk from the milk of the same cow on different days. These variations were not so great, however, as that of cow No. i from all the others. The milk from cow No. i was considerably richer than that from the others and gave a richer skim-milk^ but it contained about the same proportion of the total butter fat as the milk from the other cows. The average of all the results obtained shows that in this trial when new milk was diluted with an equal volume of cold water and kept in a room at about 75F., there was left in the skim-milk about 40 per cent, of the total butter fat after standing one hour; 30 per cent after two hours; 17 per cent after six hours; and 14 per cent after nine hours. An experiment was next made to ascertain whether the quick rais- ing of cream by dilution was caused by the sudden change in tempera- ture or by the dilution of the liquid through which the fat globules rise. The bottles used before were filled to the same depth with new milk. They were then put into a refrigerator until the milk had cooled to about 75F., taken out and kept in a room at 70 to 75F. The details of the record are given in the table. 3 2 BULLETIN NO. 1 8. [November, 1891. MILK SET IN REFRIGERATOR TWO HOURS. Temper ature of refrige- rator, F. Temperature of milk, F. Per cent of cream Per cent fat in Milk used. Skim-milk after Set. Af.2h. i h. 2 h. ! 6 h. 9h. Cow No. i. July 16 . " 17 5i 58 95 96 72 76 20 20 6 7 2-3 2.2 1.8 I .2 0.9 0.8 0.7 0.3 Cow No. 3. " 16 " 17 5i 58 99 IOO 7i 76 6 6 2.8 3-3 2.6 3.1 2.2 2. I 1.8 1. 1 i 0.8 0.4 0.4 Cow No. 4. " 16 " 17 5i 58 100 IOO 7i 76 6 6 2-5 2.8 2-5 1-9 9 7 1.6 0.8 Mixed Milk, " 16 4 in. deep. " 17 5i 58 96 97 72 76 8 8 3 3-4 2. 4 2-5 2.2 1.6 4 .1 0.9 0-5 Mixed Milk, " 16 9 in. deep. " 17 5i 58 94 95 75 79 3 3-4 2.7 2.4 2-3 1.6 .6 .2 i 0.6 ^T 0.2 Mixed Milk, " 16 pan 3 in. deep. " 17 5i 58 94 95 73 76 , 3 3-4 2.2 2.1 i-7 0.8 0.8 o-5 An average of the duplicate trials shows a great difference in the cream rising on milk of the different cows. There is not near the uniformity that was observed when the milk was diluted with water. The same calculation used before shows the per cent of the total butter fat of the whole milk left in the skim-milk to be as follows: PER CENT OF THE TOTAL BUTTER FAT LEFT IN THE SKIM-MILK, Milk set. i hour. 2 hours. 6 hours. 9 hours. Cow No. i. July 16 30.6 24 12 93 ' ' i7 25 I -) A Average 26.8 19 10.5 6.3 Cow No. 3. July 16 73 5 60 3 33- 5 1^ " 17 60 31 22.6 ii. 3 Average 67.7 45-5 28 12. I Cow No. 4 July 16 QO QO 6q 1:7 " 17 85 57 50 24 Average 88.5 73-5 59-5 40.5 Mixed Milk. July 16.. 73 7 43 27 " 17 67 43 30 14 Average 70 56.5 36.5 15-5 The results from this work on cream raising by dilution, show [i] that with rich milk and with that from a new milch cow, the cream rose as completely when the new milk was quickly cooled to 7oF. without the addition of water as it did when diluted with an equal quantity of water. [2] The rising of the cream was more complete in a given time, and was hastened by diluting the milk from cows that were not fresh or that gave a considerable quantity of average milk. E. H. FARRINGTON, M.S., Chemist. UNIVERSITY OF ILLINOIS-URBANA Q.630.7IL6B C002 BULLETIN. URBANA 17-361891-94 30112019529053