578 ANNUAL. REPORT OF THB 0£E. Doc. 



I he lot-globules above a moderate temperature tends to i)roduce but- 

 ter of soft texture. 



(2.) Regulating Richness of Cream. — The richness of cream pro 

 duced bv a separator is regulated by the rate at which the milk flows 

 into the bowl and by the rapidity with which the bowl revolves. The 

 more rapid the inflow of milk or the slower the speed of the bowl, the 

 larger the quantity of cream and the poorer in fat. Most machines 

 are provided with special arrangements for regulating the richness 

 of cream without changing the rate of inflow or rapidity of motion. 



(3.) Creaming Eflficiency of. Separators. — A good centrifugal sepa- 

 rator should not leave more than one-tenth of one per cent. (0.1 per 

 cent.) of fat in the skim-milk, when it is run under proper conditions. 



(4.) Promptness in Separating Milk. — Milk should be separated 

 as sooo as practicable after milking, and the cream should be cooled 

 down to 50 degrees F., or below. 



(5.) Advantages of Creaming by Centrifugal Machines. — Among the 

 advantages that may be mentioned in favor of employing centrifugal 

 machines in separating cream from milk are the following: 



(a.) There is a great saving of fat. Gravity systems of creaming 

 leave, on an average, 0.5 per cent, of fat or more io the skim-milk, 

 while good separators properly handled should not leave more than 

 0.1 per cent. In a large number of comparative experiments made 

 by the writer, where milk from different breeds of cows was creamed 

 both by the deep-setting gravity system and by centrifugal machine. 

 it was found that the separator effected a saving of fat amounting 

 to twenty-four to sixty-five pounds a year foi' each cow. In the form 

 of butter, at twenty cents a pound, this saving for each cow would be 

 equivalent to $5.00 to |15.00 a year. 



(b.) In the case of cream separation by the gravity system, the 

 composition of the cream is not under satisfactory control, and will 

 vary, even under the most uniform conditions of creaming, 5 per 

 cent, of fat or more. Ooe can never be sure in advance of what the 

 fat content of gravitv-raised cream will be. In the case of cream 

 separated by a centrifugal machine, one can so regulate the condi- 

 tions as to produce cream with just the desired amount of fat in it. 

 It is thus easy to produce a product that is uniform in composition, 

 since the conditions aie under easy control. In the case of produc- 

 ing cream for sale as such, it is very important that the product shall 

 be uniform from day to da^-. 



(c.) Separator cream is more free from dirt and bacteria and will 

 keep longer than will gravity cream. Most of the dirt in milk in 

 the form of solid particles is completely removed by the centrifugal 

 separator, as the appearance of the separator slime abundantly 

 testifies. 



