120 EVAPORATED MILK STERILIZING 



CHAPTER XL 

 STERILIZING 



The sealed cans are now ready for the sterilizer. If they 

 cannot be sterilized within an hour or two they should be sub- 

 merged in ice water or placed in a refrigerating room until the 

 sterilizer is ready for them. This precaution is especially ad- 

 visable in summer. 



Purpose of Sterilization. The chief purpose of subjecting 

 the evaporated milk to the sterilizing process is to kill all germ 

 life and, therefore preserve the product permanently. When the 

 hermetically sealed cans come from the sealing room, their 

 contents are not sterile. The only means to preserve this milk 

 is to subject it to temperatures high enough to kill all forms of 

 ferments, organized and unorganized, vegetative cells and spores. 

 The success of the manufacture of this product depends to a 

 large extent on the process of sterilization. 



Aside from this, the manufacturer aims to gain another com- 

 mercially important condition, namely, to prevent the separation 

 of the butter fat. Before sterilization, there is nothing to prevent 

 the fat from separating out in the evaporated milk and from 

 churning in transportation, unless the evaporated milk was 

 homogenized. This is a highly undesirable characteristic, mak- 

 ing the goods unmarketable. The sterilizing process helps to so 

 change the physical properties of the milk, that this tendency 

 of the fat to separate is greatly minimized. The sterilizing 

 temperatures used, further lend to the evaporated milk a creamy 

 consistency and yellowish color, giving the product a semblance 

 of richness. 



Sterilizers. The predomi- 

 nating apparatus used for ster- 

 ilizing is a huge, boiler-like, 

 hollow, iron cylinder or box. 

 It opens either at one end 

 or on the side. Its interior 

 is equipped with a revolving 

 framework, steam inlet and ex- 

 haust, a water distributing pipe 

 running the entire length of 



