CONDITIONS AFFECTING THE CHURNAIULITV OF CREAAI 241 



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

 otlier wa)-s injure the butter. Curd and sugar should be 

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

 food for bacteria which niaj- be present. 

 An excess of curd is also faA'oral^le to 

 the formation of mottles.' 



Too low a temperature is also un- 

 desirable, although it is better to ha\'e 

 the temj)erature a little low ratlrer than 

 too high. When the churning tempera- 

 ture is too low, difficult churning is 

 likely to occur. Cream at a low tem- 

 perature Ijecomes more viscous. On 

 agitation in tlie churn such cream, if it is 



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

 without agitating; consequently no clrurning will take place. 

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

 tion that it takes up sait with difficultx', anfl when this hard 



Fig. 8.5 .- 



Secticinal \'ie\v (jf 

 Dual 



Fig. 8(). — Perfection Dreailnaughl Churn ij .\ Cherr_\' Cu. 



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 Aalue of the butter. 



The degree of hardness of the fat in the cream is the goA'ern- 

 ing factor in decirling the churning temperature. The churning 



' Bui. No. J63, (Geneva, X. Y. 



