128 THE BOOK OF BUTTER 



be 48° to 54° F. After the ripening process and several 

 hours before the cream is placed in the churn, the tem- 

 perature should be lowered to the proper degree for 

 churning. The reason for this care in cooling the 

 cream is that it requires a few .hours for the fat to 

 recrystallize or harden. In cooling, natural ice should 

 not be put in the cream, foi- much of it contains harm- 

 ful bacteria. 



The butter-maker should regulate the temperature, the 

 richness of the cream, and all other factors, in order 

 that the butter will not have a broken grain and be 

 greasy, but will be firm and waxy. He must remember 

 that the proper churning temperature is that at which 

 the churning process will require thirty to forty-five 

 minutes when all other factors are normal. 



96. Richness of cream. — It is easy to understand that 

 rich cream, in which there is a comparatively small 

 amount of serum, will churn more readily than cream 

 containing a greater amount which interferes with the 

 concussion of the fat globules. For easy churning, the 

 cream should contain 30 to 40 per cent of milk-fat. Thin 

 cream is often the cause of difficult churning. Sometimes 

 it is necessary to churn cream with a low percentage of 

 milk-fat, but this is at the expense of time or the quality 

 of the butter, and often of both. If the cream is too rich 

 in milk-fat, it will adhere to the sides of the churn. This 

 may cause difficult churning. 



97. Ripeness of cream. — Ripe or sour cream is less 

 viscous than sweet cream. This viscosity may consist 

 in part of albumin, some of which may be seen in the 

 slime around the separator bowl after separation, and 

 part of the membrane about each fat globule, if such a 

 membrane is present. Regarding the inclosure of the 



