The Cornell Reading-Courses 



PUBLISHED BY THE 

 NEW YORK STATE COLLEGE OF AGRICULTURE AT CORNELL UNIVERSITY 



B. T. Galloway, Dean 



COURSE FOR THE FARM. ROYAL GILKEY, Supervisor 



Entered as second-class matter at the post office at Ithaca, New York 



VOL. IV. No. 82 



FEBRUARY .15, 19 15 



DAIRYING SERIES 

 No. 5 



CREAM SEPARATION 



E. S. Guthrie 



REAM SEPARATION 

 is one of the important 

 processes in the handling 

 of dairy products. The 

 dairyman who uses a 

 cream separator is in- 

 terested- not only in the 

 proper operation of his 

 machine in order to pre- 

 vent imdue loss of milk- 

 fat, but also in the prop- 

 er location of the sepa- 

 rator from the stand- 

 point of sanitation and 

 convenience. The pur- 

 pose of this lesson is to give the persons operating cream separators an 

 understanding of the principles of separation as well as a few suggestions 

 concerning the operation, the location, and the care of separators. 



SEPARATION BY THE FORCE OF GRAVITY 



The separation of cream and skimmed milk is possible because of the dif- 

 ference in the specific gravity of these two substances. The specific gravity 

 of cream is difficult to obtain because cream is exceedingly variable in fat 

 content and because it has a tendency to incorporate air. The specific 

 gravity of milk-fat is .90 or .91. In view of the fact that about one-fourth 

 to one-half of cream is milk-fat, it is readily seen that cream is much lighter 

 than skimmed milk. The force of gravity acts in direct proportion to th^ 



[1871I 



