CONDITIONS AFFECTING THE CHURNABILITY OF CREAM 241 



which, when present together in butter, are likely to sour and in 

 other ways injure the butter. Curd and sugar should be 

 excluded from butter as much as possible, in order to eliminate 

 food for bacteria which may be present. 

 An excess of curd is also favorable to 

 the formation of mottles. 1 



Too low a temperature is also un- 

 desirable, although it is better to have 

 the temperature a little low rather than 

 too high. When the churning tempera- 

 ture is too low, difficult churning is 

 likely to occur. Cream at a low tem- 

 perature becomes more viscous. On 

 agitation in the churn such cream, if it is 



very thick, will adhere to the sides of the churn and rotate with it 

 without agitating; consequently no churning will take place. 

 Too low a temperature brings the butter in such a firm condi- 

 tion that it takes up salt with difficulty, and when this hard 



FIG. 85. Sectional view of 

 Dual. 



FIG. 86. Perfection Dreadnaught Churn (J. A. Cherry Co.) 



butter is being worked, a large portion of the water in the 

 butter is expressed, and the overrun will be lessened to a great 

 extent without increasing the commercial value of the butter. 



The degree of hardness of the fat in the cream is the govern- 

 ing factor in deciding the churning temperature. The churning 



1 Bui. No. 263, Geneva, N. Y. 



