STERILIZATION 143 



II. STERILIZATION 



By sterilization of milk is understood a long contin- 

 ued boiling, or heating to a temperature above the boil- 

 ing point as 105 to 110 C. (220 to 230 F.). The 

 superiority that is claimed for sterilization over pasteur- 

 ization is that all of the bacteria are killed and the milk, 



Flo. 10. 



Kleemaun's high-pressure pasteurizer and regenerative heater, a, water of condensation 



6, to the cooler. 



consequently, will keep for an unlimited time. But 

 nearly all the examinations of " sterilized milk" bought 

 in the market, that have been made, up to the present 

 time, have shown that the milk is not sterile but con- 

 tains the spores of bacteria. On the whole, sterilization 

 offers no special advantage over pasteurization, on ac- 

 count of the unpleasant taste of sterilized milk, due to 

 changes in the albumen and lactose, and on account of 

 the greater expense connected with it. Sterilization has 



