MILK AND ITS PRODUCTS 167 



Centrifugal Method (Hand Separator). Dairies hav- 

 ing four or more cows should cream their milk by the cen- 

 trifugal method, the hand separator. The saving of but- 

 ter fat with this method soon pays for the cost of a sep- 

 arator. Moreover it has the additional advantages over 

 the gravity methods of creaming in providing fresh, sweet 

 skim milk for feeding purposes, and yielding cream of 

 any desired richness. 



Efficiency of Creaming With a Separator. Under 

 favorable conditions a separator should not leave more 

 than .05% fat in the skim milk by the Babcock test 

 There are a number of conditions that affect the efficiency 

 of skimming and these must be duly considered in making 

 a separator test. The following are some of these con- 

 ditions : 



A. Speed of bowl. 



B. Steadiness of motion. 

 C. 1 Temperature of milk. 



D. Manner of heating milk. 



E. Amount of milk skimmed per hout- 



F. Acidity of milk. 



G. Viscosity of milk. 

 H. Richness of cream. 



I. Stage of lactation. (Stripper's milk.) 



A. The greater the speed the more efficient the cream- 

 ing, other conditions the same. It is important to see that 

 the separator runs at full speed during the separating 

 process. 



B. A separator should run as smoothly as a top. The 

 slightest trembling will increase the loss of fat in the 

 skim milk. Trembling of bowl may be caused by any of 

 the following conditions: (i) loose bearings, (2) sepa- 



