CHAPTER XV. 



PASTEURIZATION AS APPLIED TO BUTTER MAKING. 



The process known as pasteurization derives its name 

 from the eminent French bacteriologist Pasteur. It con- 

 sists in heating and cooling in a manner which will de- 

 stroy the vegetative or actively growing bacteria. Milk 

 or cream is also considered pasteurized when only the 

 bulk of the vegetative bacteria is destroyed. 



Beginning of Cream Pasteurization. About twenty 

 years ago Storch, the noted Danish scientist, succeeded 

 in isolating from milk the bacteria that are needed in 

 successfully ripening cream. Cultures of these bacteria 

 were prepared and propagated in his laboratory and 

 placed upon the market for cream ripening. It became 

 evident to Storch, however, that the best results could 

 not be expected when these cultures were added to cream 

 that was already teeming with various species of bacteria. 

 This led him to the idea of preparing a clean field for 

 his cultures by destroying the germs that already existed 

 in the cream by pasteurizing it. After this treatment the 

 cream was inoculated with the desirable germs that he had 

 isolated and propagated for this purpose. The result of 

 this practice was that it became possible to produce butter 

 which not only possessed a very fine flavor but which was 

 characterized by its extreme uniformity and good keeping 

 quality. 



Storch soon succeeded in introducing this method of 

 butter making into Danish creameries which has done 

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