122 MILK [vn 



skim milk. From calculations made, it has been 

 estimated that, working on a large scale, the separator 

 yields about 93 per cent of the fat. This is probably 

 about 20 per cent more than is obtained by the old 

 method. The saving effected by using the centrifugal 

 separator is thus seen to be considerable. 



The efficiency of the centrifugal separator is de- 

 pendent on the rate at which it is worked, as well as 

 on the temperature, composition, and amount of milk 

 treated. 



Milk transported to a distance, and consequently 

 submitted to a disturbance, or milk which has been 

 boiled, does not separate so well as fresh milk. It 

 has also been noticed that milk very rich in fat does 

 not separate so thoroughly as milk containing an 

 average amount. And here it may be well to point 

 out that skim milk produced by a separator forms 

 a better article of food when used for the feeding of 

 pigs than that obtained by the other methods ; for, 

 although it contains less fat, it is freer from lactic 

 acid, and forms a much more palatable food. 



Preliminary Souring of Milk or Cream before 

 Churning. It was early discovered that milk or 

 cream, in which the process of souring had gone on 

 to a certain extent, was more easily churned, and 

 yielded more satisfactory results, than when in the 

 fresh condition. It has hence been customary to 

 "ripen" cream before churning. Why this should 



