THE PASTEURIZATION OF MILK 



which are enclosed in a large chamber which is 

 filled with hot water. The apparatus somewhat 

 resembles the tubular boiler. After heating, the 

 milk is held in three upright cylindrical Park hold- 

 ing tanks, the milk passing through the entire se- 

 ries. In this holding apparatus tests previously 

 made indicated that milk is held for from thirty- 

 five to forty minutes. 



In making this test, the first sample was taken 

 from the raw milk. This sample, when set, showed 

 14 per cent, of cream and 3.8 per cent, butter fat. 

 A second sample was taken from milk which was 

 heated to a temperature of 143 and held for from 

 thirty-five to forty minutes. This sample, when 

 set, showed 14 per cent, of cream and 3.8 per cent, 

 butter fat. In order to vary the experiment the 

 temperature of the milk entering the holder was 

 then raised to 145, at which temperature the milk 

 was maintained until the process of pasteurizing 

 was completed for the day. The milk in the filled 

 holding tanks was allowed to stand for thirty 

 minutes and a sample was taken from that which 

 was being discharged from the holding tank, which 

 showed, on standing, 14 per cent, of cream and 

 3.85 per cent, butter fat. A fourth sample was 

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