CHAPTER XV 



MECHANICAL LOSSES AND THEIR INFLUENCE ON 

 BUTTER OVERRUN 



Mechanical losses are such as occur during the various 

 stages of the manufacturing process and in the testing of milk 

 and cream. Mechanical losses are not absolutely avoidable, 

 yet many of such losses may often be materially reduced. 



LOSSES THAT OCCUR DURING THE 

 MANUFACTURING PROCESS 



Fat Losses in Skim Milk.— The loss of butter fat in the skim 

 milk is a factor of importance to creameries receiving whole 

 milk. In accordance with Danish experiments/ the aver- 

 age loss of fat in skim milk based on a series of experiments 

 with three different types of factory cream separators amounts 

 to about .07 per cent. It will probably be close to the actual 

 loss if it is estimated at .1 per cent for the American creameries. 



Washburn, Dahlberg, Sorensen, and M. P. Mortensen ' 

 found that 1.64 per cent of the total fat received at the factory 

 was lost in the skim milk. 



For ascertaining the amount of fat lost in the skim miUc, the 

 amount of skim milk obtained is not conveniently determined 

 by weighing, but it may readily be calculated. For that pur- 

 pose let m represent pounds of whole milk to be skimmed, s, 

 pounds of skim milk, c, pounds of cream obtained, p, the per 

 cent of fat contained in the whole milk, pi, the per cent of 

 fat contained in the cream, and a, the per cent of fat in the 

 skim milk. 



1 Beretning No. 70 fra den Kgl. Veterinaer og Landbohojskoles Laboratorium 

 for landokonomiske Forsog, 19 10. 

 ' Bulletin 177, Minnesota, 1918. 



181 



