PASTEURIZATION TEMPERATURES 



203 



method of heating has been recommended by him for the pur- 

 pose of destroying the enzymes in the cream. Butter made from 

 cream thus treated has shown unusually good keeping qualities, 

 and he reports that it does not go fishy when placed in storage. 

 One of the advantages of pasteurization is that it destroys all the 

 pathogenic micro-organisms in the cream if any be present. 

 Efficient pasteurization destroys from 99.5 to 99.9 per cent of 

 the organisms present in cream. Pasteurization, however, does 



FIG. 66. The Simplex regenerative pasteurizer (apart). 



not put poor cream in a condition where good butter can be 

 made from it. 



Pasteurization and sterilization are not the same. The 

 latter means that milk or cream, or any other liquid substance, 

 has been heated so often or to a high enough temperature to 

 entirely destroy every living micro-organism present. In order 

 to get a substance thoroughly sterilized without heating under 

 pressure, it is essential that it be heated about thirty minutes 

 on each of three or more consecutive days. 



