212 PRACTICAL DAIRY BACTERIOLOGY 



than that which is popular in Europe. Hence, to the American 

 taste, up to the present time, the butter from pasteurized cream 

 is not superior to that made from unpasteurized cream. 



In pasteurizing cream for butter-making the methods already 

 described are used. Sometimes the whole milk is run through 

 a pasteurizer, and the cream subsequently separated from it. 

 Sometimes the milk is first run through the separator, and the 

 skim-milk and the cream pasteurized separately afterward. The 

 effect of high temperature is not so marked upon cream as it 

 is upon milk. A temperature of 180 is quite sure to produce 

 the cooked taste in milk; but this temperature, or even a higher 

 one, can be used upon cream without danger of developing the 

 cooked taste in the butter, for these cooked flavors do not seem 

 readily to affect the fat. A temperature even as high as 185 

 or 190 might be used without special detriment. 1 It has been 

 thought that the use of pasteurization is deleterious to the grain 

 of the butter, but this can be remedied by cooling the cream to 

 a temperature of 48 before churning. 



One advantage that comes from the pasteurization of cream 

 in butter-making is that butter made from such cream keeps 

 better than butter made from unpasteurized cream. 2 The reason 

 for this is not difficult to understand. Pasteurized cream, sub- 

 sequently inoculated with a pure culture, will contain practically 

 nothing but lactic bacteria, and the lactic bacteria, as we have 

 already noticed, prevent the growth of putrefactive and other 

 organisms. The butter made from such cream will, therefore, 

 show very few of the types of bacteria that are liable to give 

 rise to undesirable fermentation, and for this reason the keeping 

 property of the butter is enhanced. It is even found that the 

 keeping of the butter is increased by the use of pasteurized 

 water for washing the butter after the churning. 



iDean and Harrison. Bui. 117, Ontario Agr. Col., 1902. 

 2 Dean and Harrison. Ont. Agri. Col. Bui. 117, 1902. 

 Farrington and Godfrey. Ann. Rep. Wis. Exper. Sta., 1903. 



