CREAM RIPENING 229 



season is difficult. If the fermentation of the cream during the 

 ripening process is at all responsible for the flavor of the result- 

 ing butter, the systematic use of specific bacteria in the cream 

 ripening process is bound to greatly assist in securing a uniform 

 flavor in the butter. If, on the other hand, no attempt is made to 

 control the bacterial flora of the cream and its development, either 

 by pasteurization which destroys most of the organisms present, 

 or by ripening with pure cultures of lactic acid bacteria, or by 

 both, the butter maker is powerless to regulate the flavor in 

 the finished product and the flavor of the butter will largely 

 vary with the character of the cream that he receives. 



3. To Increase the Exhaustiveness of Churning. Other 

 conditions being the same, the churn yield from a given quantity 

 of butter fat depends on the exhaustiveness of the churning. The 

 more exhaustive the churning, the less of the butter fat will be 

 lost in the buttermilk and the larger will be the amount of butter 

 made. 



Experience has amply demonstrated that sour or ripened 

 cream will churn out more readily and more exhaustively than 

 sweet cream. This means less labor and time required to com- 

 plete the churning and more butter made from sour cream than 

 from the same amount of butter fat in sweet cream. This fact 

 is due to the difference in the viscosity between sweet and sour 

 cream. Sweet cream is of relatively viscous consistency due 

 to the colloid condition of the casein. The viscosity minimizes 

 the concussion to which the fat globules are exposed during 

 the churning process, and therefore delays the formation of 

 butter granules. For the same reason, also, a relatively large 

 proportion of the small fat globules is not churned out at the 

 time the churn is stopped and there is excessive loss of fat 

 in the buttermilk. 



In the ripened cream the viscosity is very materially re- 

 duced. The acid alters the physical condition of the casein, 

 and other nitrogenous bodies precipitating them into finely 

 divided particles. This changes the mechanical condition of 

 the cream from a viscous body to a granular, friable body. In 

 this sour cream the fat globules encounter less resistance and 

 have greater freedom to respond to the agitation caused by the 



