VARIATION OF FAT IN MILK AND CREAM 



89 



at 90 F., a drop in the temperature to 50 F., caused the 

 amount of cream delivered to decrease to 5.5 pounds and the 

 skim-milk to increase to 94.5 pounds. These results are graph- 

 ically illustrated in Fig. 17. 



The results expressed in Fig. 1 7 show that when the tempera- 

 ture of the milk is decreased below normal, the richness of the 

 cream increases. At 90 F., the cream contained 26 per cent fat. 

 At 50 F. it contained 40 per cent fat. The increase in the test 

 of the cream from the cold milk would be still greater, if it were 



EFFECT OF TEMPERATURE UPON RICHNESS OF CREAM 



TEMPERATURE OF MILK 90-95 F. 



1OO LBS. OF 3.9.* MILK 

 CREAM CONTAINS 3.9 LBS. FAT 



85 LBS. 



SKIM-MILK 



26* 



1 5 LBS. CREAM CONTAINS 3.9 LBS. FAT 

 TEST OK CREAM = 26# 

 ff x100=26# 



TEMPERATURE OF MILK 50 F. 



100 LBS. OF 3.9# MILK 

 CREAM CONTAINS 2.2 LBS. FAT 



5.5 LBS,CREAM 



94.5 LBS. 

 SKIM-MILK 



5.5 LBS. CREAM CONTAINS 2.2 LBS. FAT 

 TEST OF CREAM =40# 



FIG. 17. 



not for the fact that at that temperature a large amount of fat 

 is lost in the skim-milk. 



The Proper Temperature for Separation. The best practical 

 temperature at which to separate the milk on the farm is about 

 90 F. The milk is never in better condition for separation than 

 immediately after it is drawn. It then has a temperature of 

 about 90 F. to 95 F. If the milk is allowed to cool to a much 

 lower temperature, as is the case in the winter, when the separator 

 is operated only once per day, or once in several days, it should be 

 warmed up to about 90 F. before it is run through the separator; 

 otherwise there is bound to be a considerable variation in the 

 cream test and also an increased loss of fat in the skim-milk. 



