THE PASTEURIZATION OF MILK 



complaint among the users of milk pasteurized in 

 the bottle. 



An objection which may be a serious one at 

 times is this. If the bottle caps are not abso- 

 lutely tight, as may occur when bottle necks are 

 chipped or uneven, there is an opportunity for 

 water to be drawn into the bottle. When the cooling 

 is being carried on there is, of course, a partial 

 vacuum produced in the space above the milk, and 

 if in cooling the bottles are immersed in water, 

 then the water might be drawn into the bottle. If 

 the water were impure the danger becomes ap- 

 parent. 



A certain advantage in the use of the bottle pas- 

 teurizing process from a commercial point of view 

 becomes apparent when only small amounts of 

 milk are to be treated. If individual dairies are 

 compelled by legal requirements to pasteurize the 

 milk sold, it is a comparatively inexpensive mat- 

 ter to equip for pasteurizing in the bottle. The 

 only equipment necessary is a tank large enough 

 to immerse the filled bottles; facilities for supply- 

 ing hot water to the tank, and also for replacing 

 the hot water with cold when the heating is ac- 

 complished. Heat-recording devices are manu- 

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