BUTTER DEFECTS 511 



butter. It is caused either by faulty pasteurization or by im- 

 proper handling of frozen cream. 



If, during the process of pasteurization the hot cream is 

 allowed to repose in a vat without agitation, as may be the case 

 with flash pasteurized cream that is not run over a continuous 

 cooler, or with vat pasteurized cream with the coil at rest during 

 the holding period, there is a tendency for the butter fat to run 

 together, "oil-off" and gather in the form of butter oil on the 

 surface of the cream. When the cream is subsequently cooled 

 this butter oil crystallizes or granulates^ giving the butter a 

 mealy body. This can best be avoided by guarding against 

 excessively high temperatures of pasteurization and by keeping 

 the cream thoroughly agitated while hot and until it has been 

 cooled to a temperature at which the butterfat congeals, i. e., 

 about 70 F. or below. 



The experience of many creameries has been that in winter, 

 when some of the cream arrives at the factory in frozen condi- 

 tion, butter is prone to be mealy, and the mealy condition of 

 such butter has therefore been attributed to frozen cream. A 

 careful study by the author of this phenomenon has shown that 

 frozen cream, as such, does not produce mealiness, but that 

 frozen cream may and does become the cause of mealiness in- 

 directly by improper handling of this cream. 



For further details see Chapter IV "Receiving Milk and 

 Cream." 



Finally, experience has shown that mealiness resulting from 

 either of the two fundamental causes, the curd precipitation and 

 the "oiling-off" of the fat, is characteristic more especially of 

 the use of the holding process of pasteurization than the flash 

 process. In the flash process the cream is heated and cooled 

 quickly, not giving the particles of curd sufficient time to con- 

 tract and harden excessively, and the cream is subjected to 

 continuous agitation until it is cooled, thus largely preventing 

 the "oiling-off" of the fat. Butter resulting from the flash 

 process usually has a clearer and smoother body and is more 

 completely free from mealiness than butter made from cream 

 pasteurized by the holding process. 



Summary of Prevention of Mealiness. In brief, then, the 

 mealy body of butter can be avoided by : 



