VARIATION OF FAT IN CREAM 91 



of buttermilk, augmenting the loss of fat and therefore reducing 

 the churn yield. 



Too thick cream is undesirable because it may cause the~sep- 

 arator to clog, it increases the loss in handling, it is difficult 

 to properly sample and interferes with the accuracy of the test. 



The most satisfactory cream for butter-making is that which 

 tests about 30 to 40 per cent fat. It is desirable to produce 

 somewhat richer cream in summer than in winter to prevent 

 excessive souring in summer and difficult handling in winter. 



Effect of These Factors upon the Skimming Efficiency of the 

 Separator. The richness of the milk has no effect on the com- 

 pleteness of the skimming. 



The richness of the cream, within reasonable limits, has no 

 effect on the completeness of the skimming. The skimming of 

 very rich cream causes a large loss of fat in the skim-milk in the 

 case of certain makes of separators, due to the clogging of the 

 machine. 



The Rate of Inflow Greatly Affects the Completeness of the 

 Skimming. If more milk is run into the machine than the capac- 

 ity of the machine calls for, there is excessive loss of fat in the 

 skim-milk. If the rate of inflow is reduced below the capacity of 

 the skim-milk outlet, the separator delivers no cream at all. 



The Speed of the Separator Greatly Influences its Skimming 

 Efficiency. Excessive speed does not increase the completeness 

 of the skimming. Insufficient speed increases the loss of fat in 

 the skim-milk. A separator run at half speed may cause one-half 

 of the fat of the milk to be lost in the skim-milk. 



The Temperature of the Milk Affects the Skimming Efficiency 

 of the Separator. For all practical purposes a temperature of 

 90 F. causes efficient skimming. At lower temperatures there is 

 excessive loss of fat in the skim-milk. 



The Amount of Water or Skim-milk used to Flush the Bowl 

 Regulates the Amount of Fat Lost in the Bowl and Pan. If the 

 bowl is not flushed at all, or insufficiently, varying amounts of 

 fat may be lost. If the bowl is flushed until the cream discharge is 

 watery, most of the fat in the bowl and pan is recovered and 

 saved. 



