174 Testing Milk and Its Products. 



cream from the different patrons varied only from 16.9 

 to 19. 8 per cent. fat. The cream of some patrons on cer- 

 tain days contained only 9.5 per cent, of fat, and other 

 patrons at times had as high a test as 30 per cent., but 

 these great differences largely disappeared when the 

 average quality of the cream delivered during a period 

 of time, like a month or more, was considered. 



210. Smaller differences in the composition of cream 

 will, however, always occur, even if the same system of 

 setting the milk, like the cold deep-setting process, is 

 used and the water is kept at the same temperature at 

 all times. This is due to differences in the composition 

 of the milk and its creaming quality; whether largely 

 from fresh cows or from late milkers; whether kept 

 standing for a time before being set or submerged in the 

 creamer immediately after milking and straining; diam- 

 eter of creaming cans, etc. Bartlett states 1 that the per- 

 centage of fat in the cream from the same cows may be 

 increased ten per cent, or more by keeping the water at 

 70 instead of at 40 F. The higher temperature will 

 give the richer cream, but the separation will not be so 

 complete, since a richer skim milk is obtained from the 

 milk set at this temperature. Separator cream is not 

 materially influenced by the conditions mentioned, as 

 the separator can be regulated to deliver cream of nearly 

 uniform richness from all kinds of sweet milk. 



211. At creameries where both milk and cream are de- 

 livered, somewhat of an injustice is done to patrons de- 

 livering cream, by paying for the amounts of butter fat 

 furnished by the different patrons. By multiplying the 



i Maine experiment station, bulletin No. 3 (8. S.) 



