A*V- Issued October 9, 1912. U. S. DEPARTMENT OF AGRICULTURE. BUREAU OF ANIMAL INDUSTRY.— Bulletin 148. A. D. MELVIN, Chibf ot Bureau. THE MANUFACTURE OF BUTTER FOR STORAGE. BY L. A. ROGERS, S. C. THOMPSON, and J. R. KEITHLEY, Of the Dairy Division. WASHINGTON: GOVERNMENT PRINTING OFFICE. 1912. Digitized by the Internet Archive in 2012 with funding from University of Florida, George A. Smathers Libraries with support from LYRASIS and the Sloan Foundation http://archive.org/details/manufOOusde Issued October 9. 1912. U. S. DEPARTMENT OF AGRICULTURE, BUREAU OF ANIMAL INDUSTRY.— Bulletin 148. A. D. MELVIN, Chief of Bureau. THE MANUFACTURE OF BUTTER FOR STORAGE. BY L. A. ROGERS, S. C. THOMPSON, and J. R. KEITHLEY, Of the Dairy Division. WASHINGTON: GOVERNMENT PRINTING OFFICE. 1912. BUREAU OF ANIMAL INDUSTRY. Chief: A. I). Melvin. Assistant Chief: A. M. Farrington. Chief Clerk: Charles C. Carroll. Animal Husbandry Division: George M. Rommel, chief. Biochemic Division: M. Dorset, chief. Dairy Division: B. H. Rawl, chief. Field Inspection Division: R. A. Ramsay, chief. Meat Inspection Division: Rice P. Steddom, chief. Pathological Division: John R. Mohler, chief. Quarantine Division: Richard W. Hickman, chief. Zoological Division: B. H. Ransom, chief. Experiment Station: E. C. Schroeder, superintendent. ' Editor: James M. Pickens. DAIRY DIVISION. B. II. Rawl, Chief. Helmer Rabild, in charge of Dairy Farming Investigations. S. C. Thompson, in charge of Dairy Manufacturing Investigations. L. A. Rogers, in charge of Research Laboratories. Ernest Kelly, in charge of Market Milk Investigations. Robert McAdam, in charge of Renovated Butter Inspection. 2 LETTER OF TRANSMITTAL. U. S. Department of Agriculture, Bureau of Animal Industry, Washington, D. C, July 23, 1912. Sir: I have the honor to transmit herewith a manuscript entitled "The Manufacture of Butter for Storage," hj Messrs. L. A. Rogers, S. C. Thompson, and J. R. Keithley, of the Dairy Division of this bureau. The paper describes the results of three seasons' storage of butter made and packed for the United States Navy under the super- vision of the bureau and two seasons' work with other butter manu- factured under commercial conditions, so as to test thoroughly the effect of storage at various temperatures upon the qualit} r of butter made by different methods. The superiority of butter made from pasteurized sweet cream is again demonstrated. This paper deals only with the keeping and commercial qualities of the butter. Besides advantages in this respect, however, pasteuri- zation also serves as a protection to the health of the consumer by destroying pathogenic bacteria, such as those of tuberculosis and typhoid fever, which are known to survive for long periods in butter made from unpasteurized cream. As the commercial storage of butter is of great economic impor- tance to the trade and to consumers, I respectfully recommend that the results of this work be published as a bulletin of this bureau. Acknowledgment is made for assistance rendered by the Fox River Butter Co., the Morton Creamery, the Steele Center Creamery, the Biscay Creamery, and the Hutchinson Cooperative Creamery. Respectfully, A. D. Melvin, Chief of Bureau. Hon. James Wilson, Secretary of Agriculture. 3 CONTENTS Page. Introduction 7 Relation of acidity of cream to keeping quality of bntter 8 Butter for the use of the Navy 10 Comparison of Navy butter made from sweet and from ripened cream 13 Butter made for storage by different methods 14 Experiments of 1910 14 Experiments of 1911 18 The influence of storage temperature on changes in butter 25 ILLUSTRATIONS. Page. Fig. 1. Diagram showing relation of acidity of cream to keeping quality of butter 9 2. Distribution of butter scores before and after storage — Raw-cream butter 23 3. Distribution of butter scores before and after storage — Pasteurized ripened-cream butter 23 4. Distribution of butter scores before and after storage — Pasteurized unripened-cream butter 24 5. Changes in butter scores after storage at various temperatures 26 5 THE MANUFACTURE OF BUTTER FOR STORAGE. INTRODUCTION. In this country the long annual period of low production of butter has made it necessary, in order to insure a fairly uniform supply, to store large quantities during the short season when the production exceeds the demand. In the spring and early summer months the quantity of butter produced is in excess of the demand. This season is followed by a few months in which the supply and the demand are nearly equal, and this in turn by a long period covering the winter months in which the supply of fresh butter is considerably less than the demand. In May, June, and the early part of July, when the supply of fresh butter is large and the quality is good, there is active buying for storage. There may be some butter put in storage later in the summer if the production holds up, but this is usually for the purpose of disposing of a temporary and perhaps local oversupply, and little butter is bought for the express purpose of holding for the winter trade. As the supply of fresh butter diminishes the storage stock is drawn upon to meet the shortage, and by the end of March or early in April, when the supply of fresh butter begins to increase again, the storage stock is nearly or completely exhausted. Butter may therefore be held in storage from May to April, a period of 11 months, although the average time is probably 2 or 3 months less. Under exceptional conditions dealers may have butter left in storage over one year, but this is usually done at a heavy loss. The development of mechanical refrigeration has been followed by a rapid increase in storage facilities and a high state of perfection in the methods of holding the large rooms at a low temperature. An insignificant quantity of butter is held in small towns in refrigerators mainly by an ice-salt system at 20° to 25° F., but the bulk of storage butter is in the great trade centers in large warehouses at tempera- tures of 0° F. and below. This low temperature is usually maintained by circulating brine in coils on the walls of the butter rooms, although in some warehouses air is cooled to the desired temperature in bunker rooms and circulated through the storage rooms by fans. In a recent book ! the statement is made that "modern butter stor- age rooms are kept below 0° F.; the butter is quite unchanged on 1 Marshall, Charles E., editor. Microbiology. Philadelphia, 1911. 55744°— Bul. 148—12 2 7 8 MANUFACTURE OF BUTTER FOR STORAGE. removal from storage * * * " The latter part of this state- ment is, however, entirely at variance with the usual experience of dealers who store butter, as well as those who have investigated stor- age problems. All butter changes slowly in storage, even at temper- atures as low as — 10° F. There is an alteration in the physical condition, the waxy texture of the fresh butter changing to a pasty consistency. This is not evident, however, except on very long storage, and is not a factor in commercial storage. The most evident alteration is in the flavor, which may change so much that the value of the butter is seriously affected. The nature of this change is not determined by the temperature of storage, since all flavors which occur in cold storage butter are also found in butter held at higher temperatures. The most common one is the so-called "storage flavor," which appears only in old butter, although in this sense butter may become old in two or three weeks. Another flavor which is a source of great trouble in butter of this class is the peculiar condition known as "fishy" flavor. This is especially objectionable because it may occur in butter which was originally of the highest quality and because its presence materially lessens the market value of the butter. The exact cause of these flavors has not been determined with any certainty, but certain factors which may influence or accelerate their development have been pointed out in previous publications of the Dairy Division. 1 ' 2 RELATION OF ACIDITY OF CREAM TO KEEPING QUALITY OF BUTTER. The importance of the acidity of the cream at the time of churning and the possibility of making butter of superior keeping quality by limiting the acidity has been especially emphasized in these publica- tions. It was shown that butter made from unripened pasteurized cream changed very little in storage, while butter made from the same cream after the usual ripening invariably went off flavor. It was also observed that while fishiness frequently developed in the ripened- cream butter, authentic cases never occurred in the butter made from sweet cream. In a tabulation of the examination of 259 samples of experimental butter from cream of known acidity, of 137 samples from cream having an acidity below 0.3 per cent, only 2, or 1 .5 per cent, were marked "fishy," while of 122 samples having an acidity of 0.3 per cent or over, 60, or 49.2 per cent, were fishy. However, in all results which are dependent on the sense of taste allowance should be made for differences of opinion and in the conception of the flavor associated with any particular designation. 1 Rogers, L. A., and Gray, C E. The influence of acidity of cream on the flavor of butter. V. S. Depart- ment of Agriculture, Bureau of Animal Industry, Bulletin 114. Washington, 1909. 2 Rogers, L. A. Fishy flavor in butter. U. S. Department of Agriculture, Bureau of Animal Industry, Circular 146. W ashington, 1909. RELATION OF ACIDITY TO KEEPING QUALITY. 9 The relation of the acidity of the cream to the progressive change in flavor is illustrated by figure 1, which shows the scores of various lots of experimental butter made from pasteurized cream, arranged in the order of the acidity of the cream at time of churning. Lot 19, in which no acidity is given, was made from overripe hand-separator cream. In some cases two lots of butter with different acidities were made from the same lot of cream. This was true of samples 13 and 14, 15 and 16, 17 and 18, 21 and 22, 23 and 24, and 25 and 26. It will be noticed that the score of butter made from cream with an acidity below 0.3 per cent ranged, with two exceptions, above 90. Fig. 1.— Diagram showing relation of acidity of cream to keeping quality of butter. On the other hand, the score of the butter made from cream with the customary acidity was variable and usually below 90. This was espe- cially true of the samples stored at 20° F., which would be expected to bring out more strongly the tendency of the butter to deteriorate. The probable nature of the relation of acidity to change in flavor has been discussed in previous bulletins of this bureau and need not be taken up here. It is evident, however, that to make butter of good keeping quality any treatment that increases the chemical instability of the product should be avoided. Butter of good quality can be made from sweet pasteurized cream and the deteriorating influence of the acid thus eliminated. 10 MANUFACTURE OF BUTTER FOR STORAGE. BUTTER FOR THE USE OF THE NAVY. Advantage has been taken by the Navy Department of the fact just stated, that department having found it expedient for several years to procure and store a year's supply of butter during the period of heavy production. This practice has enabled that department to secure butter of high quality at a minimum price. The butter has been made from pasteurized sweet cream and packed in hermetically sealed tin cans under the supervision of and according to specifica- tions prepared by the Dairy Division, Bureau of Animal Industry, Department of Agriculture. It has shown such excellent keeping quality in storage and has given such uniform satisfaction for the past three years that the method used in its manufacture has proved a desirable and proper one. The specifications covering the manufacture of this butter contain the following requirements : 1. Butter. — Shall be fresh butter made during such period of 90 days after April 15 and before August 15 as shall be most suitable for butter making in the locality of the creamery where it is to be made; from pasteurized milk or cream, none of which shall contain before pasteurization more acid in 50 c. c. than will be neutralized by 15 c. c. or 13 c. c. of tenth-normal alkali solution, as determined by Mann's acid test, for butter scoring 94 and 95, respectively. 2. Quality. — Shall be strictly of the grade of creamery "extras" and one-third must score not less than 94 and two-thirds not less than 95 at the time of packing. 3. Composition. — Moisture in the butter must not exceed 13 per cent. There must be no preservative used other than common salt, and that shall be at a rate giving not less than 2J per cent nor more than 3 \ per cent in the butter at the time of packing. 4. Packing.- — The butter must be packed in tins and the tins fully sealed at the creamery where the butter is made and within 12 hours after the time of churning. 5. Inspection. — The ingredients, manufacture, sanitation, packing, boxing, mark- ing, and shipping of the butter shall be subject to inspection by Government inspec- tors, who shall have full authority to reject any lot of milk, cream, or the finished butter, or any other requirement which does not conform in every respect to the specifications. 6. Storage. — All butter must be kept at a temperature below 50° F. after being packed and until placed in cold storage. It shall be forwarded as rapidly as carload lots are accumulated in the packing plant to such warehouse as may be designated by the Bureau of Supplies and Accounts, Navy Department, where the butter will be held at zero or lower temperature. The Navy Department has stored during the past three years 2,084,022 pounds of butter, all of which was made according to these specifications, except where occasional churnings were made from ripened cream for experimental purposes and at one creamery winch had a special contract. During the packing seasons of 1909 and 1910 a sample can of butter was set aside from each churning, and in 1911 a similar sample was taken from each day's make. These samples were handled and stored in the same way as the other butter and kept in storage for a period averaging 8 months, at the end of which time they were BUTTER FOR THE NAVY, 11 examined to determine the quality and the amount of deterioration that had taken place. Tables 1, 2, and 3 contain the data for Navy butter for the years 1909, 1910, and 1911, respectively, showing the amount packed by each creamery, the original average score, the average score after being stored, and the points lost in storage. These are summarized in Table 4, which shows the annual averages. Table 1. — Comparative deterioration in storage of Navy butter packed in 1909. Creamery Amount Original Score after roints lost No. packed. score. storing. in storage. Pounds. 1 144,000 94 91.35 2.65 2 100,008 95 89.49 5.51 3 270, 000 95 91.41 3.59 4 220,014 95.5 91.23 4.27 5 36,000 94.2 87.25 6.95 Part of the butter was examined February 5 to 10, 1910, by H. J. Credicott, Federal butter inspector on the Chicago market; W. C. Fryhofer, Federal butter inspector on the New York market; and C. W. Larson, assistant professor of dairying, Pennsylvania State College. The remainder was scored March 1 to 4, 1910, by C. W. Larson, J. C. Joshn, Federal creamery instructor for Minnesota, and Robert McAdam, field inspector of the Dairy Division. Table 2. — Comparative deterioration in storage of Navy butter packed in 1910. Creamery Amount Original Score after Points lost No. packed. score. storing. in storage. Pounds. 6 108,000 94.69 92.33 2.36 7 54,000 95.00 92.14 2.86 8 54, 000 95.00 92. 02 2.98 9 108,000 94. 01 91.90 2.11 10 108, 000 94.76 91.64 3.12 11 162,000 95.00 91 . 43 3.57 12 108, 000 94.76 91.27 3.49 These samples were scored February 28 to March 3, 1911, by C. W. Fryhofer, Federal butter inspector on the New York market; Robert McAdam, field inspector of the Dairy Division; and O. A. Storvick, Federal creamery instructor for Minnesota. Table 3. — Comparative deterioration in storage of Navy butter packed in 1911. Creamery Amount Original Score after Points lost No. packed. score. storing. in storage. Pounds. 13 162, OuO 94.92 92.72 2.20 14 72, OuO 95.00 92.68 2.32 15 108. OuO 94.53 92.57 1.96 16 162, OuO 94.67 92.51 2.16 17 108, OuO 94.67 91.24 3.43 12 MANUFACTURE OF BUTTER FOR STORAGE. These samples were scored February 13 to 15, 1912, by J. C. Joslin, Federal butter inspector on the Chicago market; Robert McAdam, field inspector of the Dairy Division; and Thomas Cor- neliuson, assistant in dairy manufacturing investigations, of the Dairy Division. Table 4. — Showing the average yearly scores, before and after storage of all Navy butter for 1909, 1910, and 1911. Year. Average original score. Average score after storing. Average points lost in storage. 1909 1910 1911 94.92 94.73 94.75 90.90 91.75 92.37 4.02 2.98 2.38 A comparison of these results shows that the average score at the time of packing has remained nearly uniform, while the average score after storing has gradually increased from 90.90 in 1909 to 92.37 in 1911, with a corresponding decrease in the deterioration in storage from 4.02 to 2.38 points. Table 5. — Average scores when removed from storage of Navy butter for 3-year period, arranged according to months in which -packed. Year and creamery. Month in which butter was packed. Date of scoring. April. May. June. July. August. September. 1909: 1 91.60 89.56 91.33 90.40 91.42 89.40 91.05 91.35 86.30 92.75 92.34 91.94 91.35 91.95 91.37 90.88 91.19 192.14 February and March" 1910. Do. Do. Do. Do. March, 1911. Do. Do. Do. Do. Do. Do. February, 1912. Do. Do. Do. Do. 2 . .. 3 4 . . 91.71 91.62 88.40 91.64 91.79 90.63 191.28 5 .. 1910: 6 7 92. 50 92.50 91.50 91.04 92.41 91.25 92.30 92.12 8 9... 91.56 91.80 92.37 10 11.... 12 90.45 91.37 93.35 1911: 13... 92.47 14.... 15 92.66 92.03 92.59 92.00 92.63 92.60 89.93 93.00 92.30 91.60 16 17... 92.23 Average. . 91.60 91.52 91.41 91.39 91.88 91.71 1 Time extended beyond Aug. 15 by the Navy Department. The above table shows that there was little variation in the keeping quality of the butter made in different months during the storage period, also that the butter in storage 1 1 months varied but little in quality from that stored 5 months. Creamery No. 5 was permitted, by special contract, to disregard the acidity and pasteurization requirements of the specifications and BUTTER FOR THE NAVY. 13 to increase the water content to 15.5 per cent on a guaranty that the butter would score 90 after being held in storage for 8 months. This butter was made from unpasteurized cream, practically one half of which was from whole milk delivered daily, and the other half from gathered cream delivered every other day. Twelve per cent starter was used and acidity of about 0.56 per cent was developed. The cream was then cooled to 48°-50° F. and held until 4 o'clock the next morning, when it was churned. The methods of packing, ship- ping, and storing were the same as at other creameries having con- tracts for Navy butter. COMPARISON OF THE BUTTER MADE FROM SWEET AND FROM RIPENED CREAM. Tables 6 and 7 show the scores of each churning made at creameries Nos. 5 and 6, respectively. These tables are given so that the dete- rioration in storage of butter made from unpasteurized ripened cream may be compared with that made from pasteurized sweet cream. Creamery No. 6 was selected for this comparison because it represents average conditions and also because a few experimental churnings, as noted in the table, were made from ripened cream. Table 6. — Scores before and after storage of Navy butter made at creamery No. 5 from unpasteurized ripened cream. Date of churning. 1909. June 1 June 2 June 3 June 4 Junes Junefi June 7 June 9 June 10 June 11 June 12 June 14 June 15 June 16 June 17 June 18 June 19 June 21 June 22 June 23 June 24 June 25 June 26 Original score. 94.00 94.00 94.00 94.00 94.00 95.00 94.00 94.50 95.00 94.50 94.00 95.00 94.00 94.50 94.50 95.00 94.50 96.00 94.00 94.00 94.00 94.00 94.00 Score after 8 months' storage. 86.00 87.00 86.00 87.00 88.50 87.00 80.00 86.00 86.00 84.00 87.00 88.50 88.50 88.00 87.00 86.00 86.00 84.00 84.00 86.00 85.00 84.00 86.00 Date of churning. June 27 Julyl.... July 3 July 5.... July 7.... July 9 July 11... July 13... July 15... July 17... July 19... July 21 . . . July 23 . . . July 24 . . . July 25 . . . July 27... July 29... July 29... July 31... August 1. 1909. Original score. Average . 94.00 94.00 94.00 95.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 Score after 8 months' storage. 94.20 87.50 89.00 88.00 87.00 90.00 88.00 89.00 90.00 90.00 89.00 90.00 87.00 88.00 88.00 87.00 88.00 88.00 90.00 88.00 87.00 87.25 It will be seen that the average score of the butter at packing was 94.20, while the average score at the end of 8 months was but 87.25, showing a deterioration of 6.95 points in storage. The judges found 90.7 per cent of all the samples showing a pro- nounced fishy flavor. 14 MANUFACTURE OF BUTTER FOR STORAGE. Table 7. — Scores be/ore and after storage of Navy butter made at creamery No. 6 from pasteurized sweet cream. Date of churning. Original score. 1910. June 2 June 3 June 4 June 5 June 6 June 7 June 8 June 9 June 10 June 11 June 12 June 13 June 14 June 15 June 16 June 17 June 18 June 19 June 20 June 21 June 22 June 23 June 24 June 25 June 26 95.00 95.00 95.00 95.00 95.00 95.00 95.00 95.00 95.00 95.00 95.00 95.00 95.00 95. 00 95.00 95.00 95.00 95.00 95.00 95.00 95.00 95.00 95.00 95.00 95.00 Score after 8 months' storage. 91.50 92.50 93.50 93.50 93.50 94.00 93.00 93.00 92.50 92.50 91.50 92.00 92.00 93.50 93.50 92.00 92.50 93.00 93.00 94.00 93.00 94.50 92.00 93.00 92.50 Date of churning. 1910 June 27 June 28 June 29 June 30 June 30 July 2 July 3 July 5 July 6 July 1 July 7 July 8 July9 July 9 July 10 July 11 July 12 July 12 July 13 July 13 July 14 July 14 July 14 Average . Original score. 95.00 94.00 95.00 95.00 95.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 94.00 Score after 8 months' storage. 92.50 92.00 92.50 91.50 92.50 92.50 93.50 92.00 93.00 92.50 93.00 i 90. 50 93.50 189.00 91.50 90.50 90.00 90.00 92.50 92.50 92.00 93.00 i 88. 00 94.69 92.33 1 This butter made from ripened cream. The average score at the time of packing was 94. G9 and the average score at the end of 8 months was 92.33, showing a deterioration of 2.36 points in storage. The judges scored but two samples below 90 points, both of which came from the experimental churnings of ripened cream, one of which was pronounced fishy. A comparison of Tables 6 and 7 shows a difference of only 0.49 points in the score at the time of packing, while after being held in storage the difference amounts to 5.08 points in favor of the butter made from pasteurized sweet cream. BUTTER MADE FOR STORAGE BY DIFFERENT METHODS. EXPERIMENTS OF 1910. In order to demonstrate the feasibility of butter dealers having butter made expressly for storage, arrangement was made in 1910 with three creameries in the vicinity of Owatonna, Minn., to make butter in accordance with our directions. One of these, which we will designate as creamery A, made butter from unpasteurized ripened cream. Another, creamery B, pasteurized the cream, added a starter, and ripened the cream in the usual way. The third, creamery C, pasteurized the cream, cooled it at once, and churned on the afternoon of the day the cream was received without the addition of starter. Brief records of the processes were made by the butter makers, but for the sake of brevity these are omitted. These creameries were of the cooperative type, receiving whole milk or sweet hand-separator cream, and were selected on account of the standing of the butter makers and MANUFACTURE BY DIFFERENT METHODS. 15 the reputation of the product. With the exception of one visit to get the work started and another when it was nearly finished, the butter makers had no supervision. The entire output of the three creameries during the experimental period was purchased by a whole- sale butter house. One tub from each churning was scored when received in Chicago by the scorer of the butter company and Mr. Joslin, of the Dairy Division. One tub from each churning was stored in the Dairy Division rooms at 0° F., one at 10°, and from most of the churnings an additional tub at 20°. This butter was packed in June and the early part of July, and was removed from storage in February, 1911, and scored by the same scorers who had scored it before storage. The results of the scorings, with the comments of the scorers, are given in Tables 8, 9, and 10, and the results for the three creameries are summarized in Table 11. Table 8. — Scores before and after storage of butter made from ripened raw cream — Creamery A. Churning No. Score of fresh butter. Comments. Storage tem- pera- ture. Score after stor- age. Comments. A8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 92 93 91 93J 91 92 93i 93 93 92J- 92 90 93 93i 92 92i 92 92£ Unclean, oily Trifle oily Curdy, salt coarse. Aroma tainted . Overworked Sour, cheesy Sour, unclean ....do Trifle unclean, sour Sour, metallic, unclean Sour, unclean, oily, metallic. Greasy, little coarse Good butter. Unclean aroma, heated, poor milk. Trifle unclean Unclean, poor cream. Sour and coarse F. 10 20 10 20 10 20 10 20 10 20 10 20 10 10 10 10 10 10 10 20 10 20 10 20 10 20 10 20 10 20 Storage, unclean, will go fishy. Strong storage. Storage. On fishy order, storage. On fishy order. Fishy. Very fishy. Fishy and storage. Fishy. Unclean, storage, on fishy order. Storage. Storage, unclean. Storage. Unclean, storage. Storage. Fishy. Storage, fishy. Fishy. Storage, on fishy order. Do. Unclean, storage, fishy order. Fishy. Storage. Do. Unclean, storage. Storage. Stale, storage. Storage, unclean, fishy order. Storage, on fishy order. Strong storage, fishy. Unclean, storage, may go fishy. Fishy. Storage. Fishy. Do. Do. Unclean, storage. Fishy, metallic. Fishy. Storage. Strong storage, on fishy order. Fishy. Storage, unclean. Storage. Fishy, storage. Strong storage. Very strong storage. Very fishy. 16 MANUFACTURE OF BUTTER FOR STORAGE. Table 9. — Scores before and after storage of butter made from pasteurized ripened cream- Creamery B. Score of fresh butter. Comments. Storage tem- pera- ture. Score after storage. Comments. 93 93J 931 93J 93 921 "94 94 93 931 921 931 93 94 93 93 94 941 941 93 941 94 93 93 92 i 931 93 931 921 92i Oily Sour Sour, wavy Wavy Wavy Sour, wavy Fine, trifle curdy Oily, weak body Weak body Oily Oily Trifle coarse Little scur and greasy, may go fishy. Little sour and greasy Trifle unclean, poor material.. Good butter, little coarse. . Sour, high acid Good butter, a little coarse. Trifle unclean and flat Mottled °F. 10 20 10 20 10 20 10 20 10 20 10 20 10 20 10 20 10 10 10 10 10 10 20 10 20 10 20 10 20 10 20 10 20 10 20 10 20 10 20 10 10 10 10 10 10 10 10 90 90 90 87 89 92 89 90 91 89 89 88 90 91 90 88 92 92 88 91 89 92 91 92 89 89 88 90 88 921 921 92 921 92 86 90 89 89 93 90 88 90 91 88 93 92 89 92 92 90 92 93 88 92 90 88 921 90" 92 86 90 89 93* 921 931 93" 91 92 931 90 93 921 Strong storage. Do. Do. Storage, on fishy order. Storage, fishy. Do. Storage, on fishy order. Trifle storage. Strong storage. Slight storage. Storage. Strong storage. Do. Storage and fishy. Strong storage. Slight storage, and curdy. Unclean, slight storage, sour. Strong storage, stale. Trifle storage. Slight storage. Strong storage, on fishy order. Slight storage. Storage, on fishy order. Strong storage, fishy. Storage, on fishy order. Strong storage, "may go fishy. Slight storage. Strong storage. Slight storage, trifle unclean. Strong storage, unclean. Strong storage. Storage, on fishy order. Storage. Storage, on fishy order. Slight storage, clean. Trifle storage. Slight storage. Do. Slight storage, but sweet. Storage, fishy. Storage, not unclean. Strong storage. Unclean, storage. Good butter, slight storage. Storage and slight fishy. Storage, on fishy order. Strong storage. Storage. Strong storage. Good butter, slight storage. Storage. Storage, may get fishy. Storage, otherwise good. Slight storage. Do. Do. Good butter, trifle storage. Storage, on fishy order. Storage, but sweet. Storage. Storage, on fishy order. Trifle storage. Storage. Storage, otherwise good. Storage and fishy. Storage and unclean. Trifle unclean and slight storage. Good butter, slight storage. Trifle storage. Fine butter, trifle storage. Trifle storage, fairly good. Slight storage. Do. Good butter, slight storage. Storage. Trifle storage, good butter. Trifle storage. MANUFACTURE BY DIFFERENT METHODS. 17 Table 10. — Scores before and after storage of butter made from pasteurized unripened cream — Creamery C. Churning No. Score of fresh butter. Cl 92 2 92 3 92 4 93 5 91 6 93 7 93* 8 93 9 93 10 11 93 12 93 13 93* 14 93 15 93J 16 94 17 94 18 93J Comments. Flat, trifle unclean . . Metallic Greasy, will go fishy. Greasy Metallic, pasty Slightly greasy. ....do ....do Clean but lacks character . ....do ....do... Metallic . Greasy . . Metallic and unclean . Sour, unclean Good butter. Sour Stor- Score age tem- after pera- age. ture. °F. 93 10 93 20 92* 93 10 92 20 92 93 10 92 20 92* 93 10 92 20 92* 93 10 92 20 93i 93 10 93 93 10 93 93 10 93 92 10 90 20 90 92 10 92 20 92 93 10 93 20 93 89 10 91 93 10 92* 91 10 92 92* 10 90* 20 91 93 10 88 20 89 90 10 93 20 91 93 10 92* 20 88 Comments. Flat but good. Cooked but clean and sweet. Good butter, flat. Flat but sweet. Trifle unclean. Unclean. Clean but flat. Slight storage unclean. Good butter. Trifle cooked flavor. Good butter, greasy. Good butter. Metallic. Good butter, trifle metallic. Clean and sweet. Clean but flat. Clean and sweet. Good butter. Sweet good butter. Clean and sweet. Trifle unclean. Unclean. Do. Cleans up sweet but flat. Not quite so good, but clean, oily. Trifle unclean. Clean and sweet. Do. Clean but greasy. Unclean. Do. Good butter. Aroma not clean, otherwise good. Trifle unclean. Do. Trifle storage, otherwise good. Storage. Do. Slight storage, otherwise good. Storage, on fishy order. Storage. Strong storage but clean. Good butter, slight storage. Slight storage. Sour but good . slight storage. Slight storage. Strong storage, on fishy order. Table 11. — Aivrage scores of Tables 8, 9, and 10 — Creameries A, B, and C. Character of cream. Raw ripened cream Pasteurized ripened cream.. . Pasteurized unripened cream Number of churnings. 18 30 i 17 Average score of fresh butter. 92.33 93.35 92.94 Storage tempera- ture. Number of tubs scored. Average score after storage. 87.33 86.94 86.33 91.20 90.28 88.47 92.36 91.91 91.41 1 Not including one churning which was not scored before storage. 18 MANUFACTURE OF BUTTER FOR STORAGE. While it is unsafe to make a too direct comparison from the data in the preceding tables, owing to the fact that the three kinds of butter were made in different creameries and from different lots of cream, nevertheless the superior keeping quality of the butter made from pasteurized sweet cream is obvious. The almost uniform occurrence of storage and fishy flavors in the ripened-cream butter and the absence of these flavors in the sweet-cream butter should not be overlooked. EXPERIMENTS OF 1911. In the following season (1911) a similar arrangement was made with the same company and butter was made for storage at two creameries. One of these, creamery E, pasteurized the cream and ripened it in the usual manner. The other divided the cream, adding a starter and ripening one-half without pasteurization, while the other half was pasteurized, cooled at once, and held until the following morning. We recommend that sweet cream be churned on the day of separation, not only to avoid the danger of development of bac- teria in the cream on standing, but also on account of the economy of time and refrigeration. However, in this case, it was not prac- ticable to arrange the churnings in this way. One of the writers divided his time between the two creameries, supervising the churn- ing records, which are summarized in Tables 12, 13, and 14. Table 12. — Churning data for raw ripened cream — Creamery D. Churning No. Fat in cream. Churning tempera- ture. Acidity of cream as lactic acid. Time re- quired for churning. Fat in buttermilk. Water in butter. 1 Per cent. 27.00 32.00 30.00 30.00 °F. 51.5 53.0 52.0 52.0 51.0 53.0 53.0 52.0 54.0 53.5 53.5 55.0 53.0 53.0 52.0 52.0 53.0 51.0 50.0 54.0 52.0 Per cent. 0.58 .55 .56 .53 .51 .48 .51 .50 .53 .56 .55 .55 .52 .51 .51 .54 .58 .54 .52 .54 .50 Minutes. 42 24 35 31 27 50 24 40 36 45 26 25 43 33 35 51 20 38 Per cent. 0.200 .200 .120 .145 .240 .175 .190 .090 .160 .170 .260 .130 .175 .115 .105 .175 .260 .190 .135 .090 .145 Per cent. 14.0 15.3 14.0 14.2 15.0 15.0 15.0 2 3 4 . 5 6 34. 00 34.00 35.25 31.00 28.00 22.00 32.50 27.50 27.00 7 8 9 14.5 15.0 15.6 15.3 15.3 15.0 14.8 15.9 15.8 14.1 16.0 14.8 15.5 10 11 12 13 14 15 16 31.50 28.00 29.00 33.50 32.50 35.50 17 18 19 20 60 83 21 Average 30. 50 52. 5 .53 36.6 .165 15.0 MANUFACTURE BY DIFFERENT METHODS. 19 Table 13. — Churning data for pasteurized ripened cream — Creamery E. Churning No. ! »*£ Churning tempera- ture. Acidity of cream as lactic acid. Time re- quired for churning. Fat in buttermilk. Water in butter. Per cent. 1 "F. 51 Per cent. 0.56 .62 .58 .57 .58 .56 .54 .53 .54 .58 .56 .56 .54 .55 .54 .55 .53 .55 .50 .54 .59 .56 .60 Minutes. 35 45 35 37 40 45 50 40 35 45 40 35 35 45 40 40 45 40 40 50 45 45 40 Per cent. 0.070 Per cent. 14.3 2 13.8 3 51 50 51 50 50 52 51 51 51 50 50 51 50 51 50 50 50 51 51 50 51 14.3 4 .120 14.6 5 13.8 6 14.0 7 .420 .170 8 36.00 40.00 30.00 34.50 34.50 14 9 .180 14.3 10 .110 .190 .140 13.5 14.1 13.1 14.1 13.7 14.1 13.7 13.8 15.2 15.0 14.5 14.0 14.2 14.0 11 12 13 14... 33.00 .140 .250 .255 15 16 32.50 33.25 35.00 36.50 30.00 35.50 17 18 .100 .175 .110 .200 19 20 21 22 23 36.00 .240 Average 34.40 50.6 .558 41.2 .179 14.1 Table 14. — Churning data for pasteurized unripened cream — Creamery D. Churning No. Fat in cream. Churning tempera- ture. Acidity of cream as lactic acid. Time re- quired for churning. Fat in buttermilk. Water in butter. 1 Per cent. "F. 51.00 50.00 49.00 51.00 50.00 55.50 51.00 51.00 52.00 52.00 52.00 51.00 51.00 50.50 53.50 54.00 51.00 Per cent. 0.14 .14 .15 .13 .24 .13 .14 .14 .14 .14 .14 .15 .15 .15 .14 .15 Minutes. 19 25 23 22 14 30 30 25 20 22 15 21 32 35 17 23 32 38 17 Per cent. 0.160 .240 .400 .400 .285 .310 .320 .325 .290 .170 .400 .215 .230 Per cent. 13.6 14.0 2 . 3 4 39.00 35.25 34.50 33.00 13.5 13.0 13.3 14.0 15.0 13.9 14.9 15.9 15.6 15.5 14.6 15.0 15.9 15.4 14.3 15.7 5 6 7 8 9 40.25 40.50 38.50 35.00 32.25 10 11 12 13 15 16 27.00 38.25 40.50 39.00 35.50 .380 .510 .190 .120 .220 17 18 19... .15 .14 20 56.00 Average 36.30 50.75 .142 24.2 .287 14.6 It will be noticed that the fat is higher in the buttermilk from the pasteurized unripened cream than in that from the raw cream or from the pasteurized ripened cream. This can be reduced by lowering the churning temperature, with, however, an increased tendency toward wavy or mottled butter. When sweet cream is churned with- out the addition of a starter the amount of buttermilk is reduced until the total loss of fat approximates that in buttermilk from an equal amount of butter made from ripened cream. 20 MANUFACTURE OF BUTTER FOR STORAGE. This butter was packed in May and the early part of June, and was scored before going into storage. The storage was arranged as with the previous lot. It was removed from storage late in January and scored as before by Mr. Joslin and a representative of the butter com- pany. Nearly all of this butter was of good quality when fresh and would have been selected for storage. The scores before and after storage are given in Tables 15, 16, and 17, and are summarized in Table 18. Table 15. — Scores before and after storage of butter made from raw ripened cream — Creamery D. Churning No. Score of fresh butter. Comments. Storage temper- ature. Score after storage. Comments. 93! 94 94 93 93J 93! 94 94 94 93J 93§ 94 94 93 16 94 17 93] 18 93 19 92J 20 93 21 93 Oily Good butter. ...do do Coarse, oily. Trifle oil v.. Trifle sour Good clean butter. Good butter do: Not quite clean Trifle heated, greasy Good butter ...do Trifle metallic, will go fishy. Good butter Trifle oily Trifle unclean Oily, will go fishy Sour and oily Sour 92 10 89 20 90 92| 10 91 92| 10 90 92 10 90 20 89 92 111 89 91J 10 89 92! 10 89 2D 90 92! 10 90 92! 10 89 92! 10 88 20 91 92 10 89 92 10 88 92! 10 90 L'll 91 92 10 90 91 10 88 20 89 92 11) 90 92 111 90 91 111 90 91 111 90 20 89 90 10 90 91 10 90 20 90 Trifle storage. Strong storage. Do. Trifle storage. Do. Do. Strong storage. Trifle storage. Do. Strong storage. Trifle storage. Will go fishy, sour. Trifle storage. Strong storage. Trifle storage. Strong storage. Strong storage, oily. Trifle storage. Strong storage. Trifle storage. Strong storage. Trifle storage. Strong storage, unclean. Trifle storage. Do. Strong storage. Trifle storage. Do. Fairly sweet, but strong storage. Trifle storage. Do. Strong storage. Trifle storage. Unclean, strong storage. Strong storage. Trifle storage. Strong storage. Trifle storage. Strong storage. Unclean, trifle storage. Strong storage. Unclean, trifle storage. Strong storage. Do. Unclean, trifle storage. Strong storage. Unclean, trifle storage. Strong storage. Do. MANUFACTURE BY DIFFERENT METHODS. 21 Table 16 . — Scores before and after storage of butter made from pasteurized ripened cream- Creamery E. Churning No. Score of fresh butter. Comments. Storage Score temper- after ature. storage. ° F. 1 ° 91} I 10 90 20 91 ( ° 92 \ 10 89 20 90 1 ° 92 i 10 89 20 90 [ ° 91 I 10 90 20 91 1 ° 92} { w 91 20 90 / ° 92 \ io 91 / o 92 \ io 92 ( o 92} \ 1° 91 20 91 / o 91 t io 91 / ° 92| \ io 88 f ° 92} { 10 92 20 91 / o 91 \ 10 91 / o 92 I io 91 1 o 92 \ io 88 20 90 / o 92 \ io 90 / o 91* \ io 91 ( o 91 \ 1° 91 20 89 / o 92 \ io 88 ( o 91 \ 1° 88 20 86 / o 92 t io 89 / o 92 I io 89 f o 91 \ 1° 89 20 87 { l8 91 89 Comments. E 1 2 3 4 12 13 14 15 16 17 18 19 20 21 22 23 94 94 94 93} 93} 93} 94 93} 93} 94 94 94 93 93 92} 93 93 93} 94 94 93} 93} 92} ('rood, trifle oily High acid High acid, but clean Trifle coarse salt for storage. Oily or heated (Trifle sour and oily, has been \ trifle heated. Not so oily Trifle sour and oily Trifle oily Good butter, oily Clean Clean, just trifle oily. . . Metallic ....do Coarse, metallic Sour and coarse, briny. Sour and coarse /Fairly clean, good starter \ aroma. Coarse salt Good butter On metallic order Oily Oily, wavy Trifle storage. Do. Do. Do. Going fishy, storage. S*orage. Trifle storage. Going fishy, storage. Storage. Trifle oily and unclean. Storage. Trifle storage. Do. Do. S f orage. Trifle storage. Do. Do. Do. Do. Do. Do. Do. Trifle storage, oily. Trifle storage. Fishy. Trifle storage. Do. Do. Do. Trifle storage, oily. Trifle storage. Do. Do. Fishy. Storage. Trifle storage. Storage flavor. Trifle storage, oily. Unclean, storage. Trifle storage, oily. Trifle storage. Trifle storage, mottled. Trifle storage. Fishy. Trifle storage. Fishy. Do. Trifle storage. Strong storage. Trifle storage. Strong storage. Trifle storage. Strong storage. Fishy. Trifle storage, mottled. Strong storage. 22 MANUFACTURE OF BUTTEE FOR STORAGE. Table 17. — Scores before and after storage of butter made from pasteurized unripened cream — Creamery D. Stor- Score age tem- after stor- Comm pera- ture. age. °F. 94 F ; ne butter. 10 93i Swee* and clean. 20 93 Do. 94 Do. 10 93$ Do. 20 93 Do. 94 Fine butter. 10 94 Do. 20 93 Sweet and clean. 93J F : ne butter. 10 92$ Sweet and clean. 20 93 Do. 94 Fine butter. 10 93$ Sweet and clean. 94 Fine butter. 10 93$ Sweet and clean. 94 Fine butter. 10 93$ Sweet and clean. 20 92 Trifle unclean. 93$ Fine butter. 10 93$ Sweet and clean. 94 Fine butter. 10 93$ Sweet and clean 20 93 Good butter. 94 Fine butter. 10 93 Sweet and clean. 94 Fine butter. 10 93$ Sweet and clean 94 Fine butter. 10 93 Sweet and clean 94 Fine butter. 10 93$ Sweet and clean 94$ Fine butter. 10 94 Sweet and clean 20 93 Good butter. 94$ Fine butter. 10 93$ Sweet and clean 94$ Fine butter. 10 93$ Sweet and clean 20 93 Good butter. 95 Fine butter. 10 94 Do. 95 Do. I 10 94 Do. 95 Do. 10 94 Do. Table 18. — Average scores of Tables 15, 16, and 17 — Creameries D and E. Character of cream. Number of chumings. Average score of fresh butter. Storage tempera- ture. Number of tubs scored. Average score after storage. Raw ripened cream Pasteurized ripened cream . . . Pasteurized unripened cream 93.55 93.52 94.61 'F. 91.86 89 48 89.88 91 74 89 91 89 64 94 18 93 16 92.88 MANUFACTURE BY DIFFERENT METHODS. 23 For convenience of comparison the results of the scoring are arranged graphically in figures 2, 3, and 4. These curves are ar- 70 60 SO 40 30 20 10 -ff?E3M. ■ ftfTcw sroR/iGe/ir O' 10' h 8* Fig. 6£ 87 88 89 Score of butt**. 2.— Distribution of butter scores before and afler storage— Raw-cream butter. • r"R£5H RrrcR utorrgc /?r 0° . 10' . „ .. -. 20' A i \ TO 60 SO 4> 30 £0 10 ~5B Q7~~ Be Scaac or aurrci? . Fig. 3.— Distribution of butter scores before and after storage— Pasteurized rlpened-cream butter. ranged to show the relative proportion of the total amount given a certain score. For instance, of the butter made from pasteurized 24 MANUFACTURE OF BUTTER FOR STORAGE. cream 52 per cent was scored 93 or 93 | when fresh and 39 per cent was scored 94 or 94$. After storage at 0° F. 60 per cent was scored 92 or 92 J. This arrangement shows little difference in the keeping quality of the butter made from raw cream and from pas- teurized ripened cream. There is a somewhat wider range of scores in the butter made from the pasteurized ripened cream, due, evidently, to the occurrence of fishy flavor in that made from the raw cream! The superior keeping quality of the sweet-cream butter is evident in 8o I 70 i\ h 60 i fRtJM nr 0° klk 50 „ 10° • , . . 20° i | i*i \\ 40 1 k / ' t/i \\ /III \ 1 30 \ j i 1 \ \ \ zo I f \ j\\\ \\ 16 /n\\ OS 86 67 OCOHC Or BUTTC.H. 9S BQ 89 30 S/ 9Z 83 04 Fig. i.— Distribution of butter scores before and after storage— Pasteurized unripened-crearn butter. its uniformity, the slight change from its original condition, and the almost complete absence of the usual cold-storage flavors. This is true not only of the butter stored at the commercial temperature, but in a lesser degree of that held at 10° and 20° F., which represent con- ditions that would tend to bring out defects and increase the differ- ence between butters of good and poor keeping qualities. This butter was made under conditions which could be duplicated by any dealer, public institution, or other large consumer wishing butter made expressly for storage. INFLUENCE OF STORAGE TEMPERATURE. 25 THE INFLUENCE OF STORAGE TEMPERATURE ON CHANGES IN BUTTER. The influence of temperature on the changes in storage butter is evidently a retardation of the rate of change, with a small but not determinative influence on the kind of flavor that develops. A cer- tain state of deterioration may be reached in three weeks at 32° F. or three months at 0° F. The kind of flavor that develops in the butter is determined almost entirely before it goes into storage, but there are certain flavors more frequently observed in storage butter than under other circumstances. There is almost always a com- plication of flavors and probably some sort of sequence of flavors; that is to say, one flavor may develop into another, and this in course of tune into a third. The temperature of storage doubtless retards this transition, and the holding of the butter for some time at one stage makes certain flavors evident which at a higher temperature would be obscured by the rapid change. The results on various lots of butter reported in an earlier bulletin l of this division showed small difference between butter stored at — 10° F. and 10° F., but a marked difference between the butter stored at 10° and 32° F. In the work reported in the present paper duplicate tubs were stored at 0°, 10°, and 20° F., partly to determine if there is much gained in the use of the lower temperature, but more espe- cially to bring out at the higher temperatures the defects in the butter. A butter that holds up well at 0° but goes off flavor at 10° or 20° would probably deteriorate more rapidly after coming out of storage at0°. The differences in the rate of change at different temperatures are perhaps best expressed by showing the average loss in points as com- pared with the score of the fresh butter. Arranged in this way, the various lots of experimental butter show deterioration as follows: Table 19. — Average deterioration of butter after storage at various temperatures. Kind of butter. Points lost after storage. Stored at 0°F. Stored at 10° F. Stored at 20° F. Raw-cream butter — Creamery A Raw-cream butter — Creamery D Raw-cream butter— All samples Pasteurized ripened cream — Creamery B . . . Pasteurized ripened cream — Creamery E . . . Pasteurized ripened cream — All samples Pasteurized unripened cream— Creamery C . Pasteurized unripened cream — Creamery D . Pasteurized unripened cream — All samples . Points. 5.0 1.7 3.2 2.2 1.7 2.0 .6 .4 .6 Points. 6.3 4.1 4.6 3.0 3.6 3.3 1.0 1.0 1.0 Points. 6.8 3.3 4.8 6.1 4.0 4.6 1.5 1.6 1.6 1 Gray, C. E., and McKay, G. L. The keeping qualities of butter made under different conditions and stored at different temperatures. With remarks on the scoring of the butter, U.S. Department of Agri- culture, Bureau of Animal Industry, Bulletin 84, Washington, 1906, 26 MANUFACTURE OF BUTTER FOR STORAGE. The relation of the score after storage at the various temperatures to the score of the fresh butter is also shown in figure 5. -» «H •» "* "O The scores amount of deterioration as indicated by the differences in the before and after storage is in a general way directly propor- INFLUENCE OF STORAGE TEMPERATURE. 27 tioned to the temperature of storage. The difference in the scores at 0° and at 10° is sufficient to warrant the use of the lower temperature even for butter of the best keeping quality. The striking thing in the table is the relative rate of change in butter made by the different methods. There was slightly less change in the pasteurized ripened- cream butter than in the raw-cream butter, but the change in the pasteurized ripened-cream butter stored at 0°F. was four times as great as that in the pasteurized sweet-cream butter at the same tem- perature, and the difference at the higher temperatures was nearly as great. Even at 20° F. the deterioration of the sweet-cream butter was comparatively slight, indicating that this butter would retain its flavor well after removal from storage. ADDITIONAL COPIES of this publication -£i- may be procured from the Superintend- ent of Documents, Government Printing Office, Washington, D. C. , at 5 cents per copy UNIVERSITY OF FLORIDA 3 1262 08928 7170