9 2 



Condensed Milk and Milk Powder 



and one too often neglected. Much of the 

 spoiled evaporated milk may be the result 

 of the use of unsanitary and unclean filling 

 machines. The fact, that the evaporated 

 milk is sterilized after it leaves the filling 

 machine, is no excuse for unclean filling ma- 

 chines. The operator should bear in mind 

 that the milk running through an unclean 

 filling machine becomes contaminated with 

 millions of bacteria. The more bacteria it 

 contains, the more difficult it is to render it 

 perfectly sterile. Furthermore, spore- 

 forms are prone to develop in the decaying 

 remnants of milk ; these spores are very re- 

 sistant and require excessively high steriliz- 

 Fig. 40. The Sprague-Coibert ing temperatures to be destroyed. 



rotary tipping; machine 



Courtesy of The Sprague 

 Canning Machinery Co. 



SEALING 



The filled cans should toe capped and sealed at once. The seal 

 must be hermetical and strong enough to withstand the strain of the 

 subsequent sterilizing process. With the exception of the "Sanitary 

 can," seals without solder have so far proven unsatisfactory in the 

 canning of evaporated milk. They are prone to weaken in the ster- 

 ilizer and cause "leakers." Most of the cans on the market contain- 

 ing evaporated milk are, therefore, sealed with solder. Sealing evap- 

 orated milk cans with solder is by far the safest method. The sani- 

 tary can, however, has been found to furnish a satisfactory seal with- 

 out solder. For details of methods of sealing see Chapter VII. 



