BACTERIA AND BUTTER-MAKING 211 



uniform grade of butter can be obtained in this way. 2. The 

 prevalence of tuberculosis has brought about the enactment of 

 a law requiring all milk that goes through the creamery to be 

 pasteurized. For this reason Denmark butter is always made 

 from pasteurized cream, and this makes it necessary to use an 

 artificial starter, since pasteurized cream will not ripen of itself. 

 The pasteurization destroys practically all of the acid bacteria, 

 and, as we have learned, when the acid bacteria are absent the 

 putrefying bacteria are quite sure to develop. Hence, pasteur- 

 ized milk requires an acid starter to insure a proper ripening. 

 Pasteurization is also said to make churning easier. 



Although the method just described is the only logical method 

 for the use of starters, it has not yet been adopted to a very 

 great extent in the United States. A small but growing number 

 of creameries use it, but for practical reasons it has not become 

 popular. The pasteurization of the cream requires the purchase 

 of new apparatus, and more work in the handling of the cream, 

 so that it involves some additional expense. Moreover, the but- 

 ter-makers have found by experience that the use of starters in 

 cream without pasteurization in the majority of cases produces 

 results that are quite satisfactory. Hence, whereas the use of 

 starters, either natural or commercial starters, has become well- 

 nigh universal in the better creameries, the pasteurization of 

 cream to prepare it for their use has not made very much head- 

 way in this country. 



In comparing the value of butter made from pasteurized 

 cream with that made from unpasteurized cream, the former 

 is found to be more uniform; but the butter made in this way 

 is not, at least to the American taste, superior to butter made 

 without pasteurization, due probably to the prevention of the 

 growth of miscellaneous bacteria that occurs before the lactic 

 bacteria develop. Pasteurized cream butter is somewhat milder 

 in flavor than that made from ordinary cream, and the Amer- 

 ican market demands a flavor in its butter somewhat stronger 



