Systems of Separating Cream. 99 



manufacture is not affected either one way or the 

 other by any of these three systems, so that their 

 relative economy rests wholly upon the complete- 

 ness, cost and ease of separation. 



Since the separation of cream from milk is al- 

 ways attended with some loss of fat, it is pertinent 

 to inquire as to the necessity of any separation of 

 the cream when butter is to be made. It is per- 

 fectly possible to manufacture butter directly, by 

 churning whole milk without separating cream, and 

 undoubtedly the first churns were skins of animals, 

 into which the whole milk was placed and then 

 agitated until the butter was brought ; but under 

 good conditions it is not possible to so complertely 

 remove the fat from the milk by a churning process 

 as by a creaming process ; so that while there is 

 some loss in separating the cream, there is usually 

 a greater loss in churning the butter from the whole 

 milk. Even when the loss of fat in the butter- 

 milk is no greater than the loss of fat in the 

 skimmed milk, the greater amount of labor required 

 to churn the whole mass of milk still renders cream- 

 ing an economical practice in the manufacture of 

 butter. 



Gravity creaming. — In separating cream by force 

 of gravity, there is a greater loss of fat, a longer 

 time required, and the various conditions affecting 

 the milk have a greater influence upon the creaming 

 than when centrifugal separation is used. The 

 conditions of the milk that affect the creaming by 

 the gravity process are : First, the size of the fat 



