248 MANUAL OF MILK PRODUCTS 



ment of the lactic acid bacteria and produce butter of the best 

 quality. 



Amount of acid to develop. — The amount of acid to be devel- 

 oped in the cream, and the degree of acidity which cream should 

 have at the close of the ripening period, will depend both on the 

 quality of the cream and the type of butter desired by the con- 

 sumer. Some markets require more, highly flavored butter 

 than others, but all the markets require that the flavor should 

 be uniform from day to day. This necessitates careful control 

 of the acid fermentation and the churning of cream with a 

 uniform acidity. While the butter-maker may be able to change 

 with some accuracy the amount of acidity in the cream, judging 

 from its appearance, taste, and odor, it is not wise to depend 

 on the senses. Several methods for accurately determining 

 the acidity are in common use, and one of these should be em- 

 ployed by the butter-maker. 



PASTEURIZATION OF CREAM FOR BUTTER-MAKING 



(See Plate XIII) 



The pasteurization of cream for butter-making is done for 

 two purposes. (1) It enables the butter-maker to eliminate the 

 miscellaneous microorganisms in the raw cream, and thus more 

 completely control the nature of the fermentation by the use 

 of starter. In this way it is possible to secure a more uniform 

 product. Whether or not the quality of the butter is improved 

 by the pasteurizing process will depend largely on the quality 

 of the raw cream. If the cream is of poor quality, the flavor 

 of the butter will be improved, while this will probably not be 

 the case if high-grade sweet cream is used. (2) The pasteuriza- 

 tion, if properly done, will eliminate disease-producing bacteria, 

 and in this way protect the health of the consumer from certain 

 diseases, the organisms causing which might be carried in the 

 butter. 



