PASTEURIZATION OF CREAM 151 



eluding from the city all butter which has not been safe- 

 guarded against these organisms, either by pasteurizing 

 the cream or by applying the tuberculin test to herds from 

 which the butter is obtained, and excluding all reacting 

 animals. 



Certainly if it is necessary to pasteurize skimmilk to 

 prevent the spread of tuberculosis among live stock, it 

 should be all the more imperative to pasteurize the cream 

 to prevent the spread of tuberculosis in the human family 

 through infected butter. 



As in the case of cream ripeners, there are a number 

 of different makes of cream pasteurizers upon the market 

 which are giving good satisfaction. Pasteurization will 

 not prove successful with any pasteurizer unless the cream 

 is heated to the proper temperature and rapidly cooled 

 to at least 65 F. immediately after it leaves the pasteur- 

 izer. 



Pasteurization of Gathered Cream. There is proba- 

 bly no problem along pasteurizing lines of greater impor- 

 tance at present than the pasteurization of hand separator 

 or gathered cream. Heretofore the apparent difficulty in 

 the way of pasteurizing this cream has been the high 

 degree, of acidity which it often reaches before delivery 

 to the creamery. Experiments and practical creamery 

 results show beyond doubt that sour cream containing not 

 less than 30% fat can be successfully pasteurized. Much 

 greater care is necessary when the fat content falls below 

 30% and buttermakers should insist upon making 30% 

 the minimum, which can easily be done with hand separa- 

 tors. 



The chief danger in pasteurizing thin sour cream is the 

 coagulation of the casein and the consequent greater loss 



