564 



MANUAL OF MILK PRODUCTS 



Showing the Extent to which Skim-milk is Diluted by Pas- 

 teurization with Steam 



Temperature (F.) of Skim- 

 milk 



At separator 



After heating 



Weight of Skim-milk 



Before 

 heating 



After heating 



Steam 

 Pressure 



Gain in 

 Weight of 

 Skim-milk 



High-pressure steam 







Lb. 



Lb. 



Lb. 



Per cent 



82° 



149° 



50 



53.2 



52 



6.4 



83 



155 



50 



53.5 



50 



7.0 



86 



174 



50 



55.0 



53 



10.0 



88 



188 



50 



55.5 



60 



11.0 



• 





Low-pressure steam 







74 



190 



100 



112.0 



8 



12.0 



76 



166 



100 



111.0 



10 



11.0 



85 



188 



100 



112.7 



10 



12.7 



80 



177 



100 



110.5 



7 



10.5 



These figures show that the skim-milk was diluted with 

 about 10 per cent of water when pasteurized by forcing steam 

 into it. The exhaust steam from an engine contains more 

 water than high-pressure steam, and skim-milk would be diluted 

 even more than shown by the above figures when exhaust steam 

 is used for this purpose. 



Pasteurizing buttermilk 



If buttermilk alone is heated to 176° F., the curd separates 

 into a sticky mass that sinks to the bottom of the can, leaving 

 clear whey above it. When mixed with sweet skim-milk and 

 heated, the latter is curdled unless very small quantities of 

 buttermilk are added. 



