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 u'NtV. OF FL LIB 
 DOCUMENTS DEPT 
 
 U.S. DEPOSITORY 
 
 A. 1. 19. 
 
 U. S. DEPARTMENT OF AGRICULTURE, 
 
 BUREAU OF ANIMAL INDUSTRY. 
 
 DAIRY DIVISION. 
 
 THE MANUFACTURE OF COTTAGE CHEESE IN CREAMERIES 
 AND MILK PLANTS. 
 
 Cottage cheese, properly made, offers a most palatable and nutri- 
 tious article of food at a relatively low price compared to the cost 
 an'fi nutritive value of many other protein foods. The simple 
 method of manufacture recommends its adoption by creameries and 
 milk plants which desire to dispose of skim milk to good advantage. 
 
 Since the quality of cottage cheese is judged by flavor and texture, 
 it is very important that the skim milk used be of good clean flavor 
 and free from foreign odors. It is possible for the maker to control 
 the texture of the cheese, but if the flavor also is to be controlled, 
 good raw material is necessary. 
 
 PASTEURIZATION OF SKIM MILK IMPORTANT. 
 
 The fresh skim milk from the separator should be pasteurized and 
 the process of manufacture begun as soon as possible thereafter, in 
 order that the fermentation or souring process may be controlled 
 to the best advantage. Perhaps the largest part of the cottage 
 cheese used is made from raw skim milk, but the advantages to bo 
 derived from proper pasteurization are so great as to make it highly 
 advisable to adopt this system of manufacture. Pasteurization 
 adds but little extra expense to the cost of making and has the 
 following important points in its favor: 
 
 1. It gives a sanitary, safe food product free from all danger of 
 disease-producing bacteria. 
 
 2. It allows the use of a pure-culture starter to control the forma- 
 tion of the mild-acid curd, giving the characteristic sour-milk flavor 
 so much desired. 
 
 Pasteurization requires but little additional work, provided suit- 
 able equipment is at hand. A temperature of 145° F., held for 30 
 minutes, gives ah efficient pasteurization and does not affect the 
 coagulability of the milk for making cottage cheese. The use of a 
 starter, however, is necessary in order to obtain the desired flavor. 
 
 101977°— 17 
 
EQUIPMENT REQUIRED. 
 
 The extra equipment necessary in the manufacture of cottage 
 
 cheese depends upon the apparatus on hand and whether the skim 
 
 milk is to be pasteurized. If pasteurization is to be included in the 
 
 , process the following apparatus is needed for making cottage cheese : 
 
 1. Pasteurizing outfit. 
 
 2. Cheese vat. 
 
 3. Drain rack. 
 
 4. Drain cloths. 
 
 5. Curd IvniveS; curd pail, and vat whey strainer. 
 
 METHOD OF MANUFACTURE. 
 
 RIPENING THE SKIM MILK. 
 
 The object of ripening is to obtain the characteristic, mild, sour- 
 milk flavor and at the same time develop the required degree of 
 acidity to cause a separation of the curd when the curdled milk is 
 heated. The temperature used for ripening depends upon the 
 quantity of starter added and how soon a firm coagulation is desired. 
 The greater the quantity of starter and the higher the temperature 
 the sooner the milk will curdle. A temperature above 75° F., how- 
 ever, is not desirable; usually 60° or 70° F. produces best results. 
 Experience will show the right combination of starter and temperature 
 to be used for best results under existing conditions. Raw milk 
 allowed to sour naturally usually develops a weU-flavored curd, but 
 the chances of obtaining a fine-fiavored product regularly are greatly 
 increased by pasteurization and the use of a good starter. In case 
 the starter is of poor quality it should not be used but natural souring 
 should be depended upon instead. It is desired to separate the curd 
 from the whey shortly after the milk shows a firm and smooth 
 coagulation. At this stage sufficient acid is present to give a good, 
 clear separation of the whey. 
 
 CUTTING AND HEATING THE CURD. 
 
 The best method of cutting the curd is to use regular cheese-curd 
 knives. They give fairly uniform cubes of curd from which the whey 
 can be expelled with small loss of fuiely broken curd passing through 
 the drain cloth. To break the coagulated milk with a mechanical 
 stirrer produces too many fine particles of curd which may be lost 
 during drainage. Steam is turned on when the curd is cut, and the 
 temperature is raised gradually. At frequent intervals the coagulum 
 is gently stirred to insure a uniform temperature and to prevent 
 undue cooking of the curd along the sides and bottom of the vat. 
 The proper temperature required to give a good, clear separation can 
 be readily ascertained by examination of the mixture in the vat. At 
 this stage the whey should be clear or show very little cloudiness. 
 
 '4* 
 
The texture of the cheese is controlled by temperature and time of 
 heating the coagulum, and the extent to which the curd is drained. 
 Considerable variation with regard to the temperature of heating and 
 the time the curd is allowed to drain is therefore necessary. A tem- 
 perature of from 90° to 105° F. gives the desired results for all normal 
 conditions, and it is rarely necessary to exceed 100° F. Heating the 
 coagulum to a higher temperature favors the more rapid expulsion 
 of whey from the curd and produces a dry, coarse-grained cheese 
 demanded by some markets. Continued heating at the temperature 
 giving a clear separation of the curd and w^hey hastens the removal of 
 whey and shortens the time of drainage. For making a smooth, 
 uniform-textured cheese care must be taken not to heat the curd too 
 long, especially at a high temperature, as such conditions tend to pro- 
 duce a dry, coarse-bodied cheese. A smooth, uniform-textured 
 cheese brings out the fine flavor to the best advantage, as it has none 
 of the harshness or grittiness fomid in the dry, coarse-grained product. 
 The use of a high temperature shortens the time required for making, 
 but much greater attention is necessary. 
 
 DRAINING THE CURD. 
 
 After the curd has been heated for from 20 minutes to an hour, de- 
 pending upon conditions, the whey may be drawn from the bottom 
 of the vat into the cloth-lined drain rack. The greater portion of the 
 whey is drawn off through the vat whey strainer and passes quickly 
 through the drain cloth. The mixture of curd and w^hey remaining 
 is then placed in the drain rack, where draijiage is completed. An 
 occasional raising and lowering of the drain cloth hastens drainage- 
 The extent of drainage depends upon the texture of cheese desired, 
 the temperature and the length of time of heating. When a fairly 
 low temperature is used, drainage can be readily controlled. It must 
 continue until there is no accumulation of free whey in the finished 
 cheese. A high temperature tends to give more free whey in the fin- 
 ished product, unless the curd is allowed to drain to such an extent 
 that the yield is materially reduced; this also increases the proba- 
 bility of producing too dry a cheese. In case the curd is draining to 
 an extent that the cheese will be too dry, it can be checked by wash- 
 ing with cold w^ater. 
 
 SALTING. 
 
 Salt is sprinkled uniformly over the curd and well worked in with a 
 paddle. The rate of salting depends upon the market demands. One 
 and one-quarter pounds to 100 pounds of curd gives a medium-light 
 salted cheese which is desired by most consumers. Light salting 
 gives the consumers more opportunity to prepare the cheese to suit 
 their individual tastes. 
 
 The addition of 1 pound of sweet cream to 10 of curd adds greatly 
 to the palatability of the cheese.' The cream can be worked into the 
 curd together with the salt. 
 
UNIVERSITY OF FLORIDA 
 
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 * 3 1262 08925 9450 
 
 PACKING AND MARKETING. 
 
 The ideal method of marketing is in the sanitary, single-service, 
 paraffined paper containers, which are convenient for the dealer to 
 handle and are attractive to the buyer. Cheese shipped in bulk 
 may be packed in butter tubs or in ordinary milk-shipping cans. 
 To insure marketing in the best condition, the cheese, immediately 
 after it is made, should be placed in the refrigerator and held at low 
 temperature until marketed. Fresh-made cottage cheese should not 
 be shipped until after it has been well cooled, for w^arm cheese favors 
 the quick development of fermentation and deterioration in quality. 
 
 YIELD OF CHEESE. 
 
 The yield of cheese varies from 12 to 22 poimds per 100 pounds of 
 milk and depends almost entirely upon the amount of moisture left 
 in the curd, which in turn is controlled by the method of manufac- 
 ture. The factors which influence the percentage of moisture in the 
 curd and determine the yield are — 
 
 1. Temperature and length of time of heating curdled milk. 
 
 2. Extent of drainage. 
 
 3. Condition of milk. 
 
 The moisture in the curd can be fairly well controlled by the 
 extent of drainage, provided too high a temperature has not been 
 used for heating and the time of heating has not been excessive. 
 The physical condition of the milk often has a marked influence upon 
 the resulting yield. A weak, unevenly coagulated curd, when cut, 
 makes a large quantity of fine curd, much of which may be lost in 
 drainage. 
 
 An ideal quality of cheese, which brings out the delicate, mild 
 flavor to the best advantage, is rather firm, smooth, and yields from 
 15 to 20 pounds to 100 pounds of milk. 
 
 WASHINGTON : GOVERNMENT PRINTING OFFICE : 1917