DAIRYING 



M/LK 

 OUTLET 



^THERMOMETER 



M/LK 

 /A/LET 



STEAM 

 /A/LET 



STEAM AND 

 --WATER 

 JACKET 



PEVOLV/NG 

 'PADDLE 



M/LK 

 CHAMBER 



Plate 30. A simple type of pasteurizer. 



is undoubtedly the most effectual of all the methods of heating 

 in so far as destroying the bacteria is concerned. It was found, 

 however, that when milk is heated to so high a temperature for 

 so long a time, the cream will not rise on it in the same way that 

 it rises on raw milk. This made the intermittent method of 

 pasteurizing milk unsatisfactory to dealers because their custom 

 ers will not believe that there is cream in milk unless they can 

 see it, even though a test of the milk shows that it may be of nor- 

 mal richness. Another peculiarity of the intermittent heating 

 is noticed in the body or consistency of cream pasteurized in this 

 way ; cream containing as high as 25 per cent fat often appears 



