174 



BUTTER-MAKING. 



method of pasteurization the substance pasteurized is exposed 

 only to a sudden temporary heat. 



The intermittent process of pasteurization tends to drive 

 off more of the undesirable taints present in the milk or cream. 

 This is especially true when stirred occasionally. If heated too 

 long the cooked flavor is likely to be more pronounced than 

 when the intarmiUeat system is used. If exposed very long 



Skim Milk Inlet 



Skim Milk Tank 



FIG. 115. Scheme for pasteurizing skim-milk by the use of exhaust-steam 

 direct. (Creamery Journal, by W. P. McConnell, Minn.) 



to the high temperature and stirred excessively during the 

 intermittent pasteurization, the butter-fat tends to melt and 

 run together, and show itself on the top of the cream in the 

 form of an oily layer. 



2. The continuous method of pasteurization is more practical 

 for large amounts of milk or cream. It is used almost without 

 exception in pasteurizing cream, whole milk, and skim-milk 

 at creameries. Neither one of the two systems destroys spores. 

 The intermittent system is the most effective because both 



