208 



SWEETENED CONDENSED MILK DEFECTS 



come in contact with the milk are the only consistent safeguards 

 against trouble from this source. 



Contamination Through "Cut-opens." It is customary to 

 empty the contents of sample cans which are cut open for any 

 purpose, back into the condensed milk of suceeding batches. If 

 these samples happen to be contaminated with the fermenting 



Fig. 54. Gaseous fermentation in 

 sweetened condensed milk 



Fig. 55. Yeast cells causing 

 gaseous fermentation 



This species is capable of 

 fermenting sugar solutions 

 containing 85% sucrose. 



germs, the defect is naturally propagated from batch to batch 

 and it is exceedingly difficult to locate the source of the trouble. 

 It is obvious that all suspicious "cut-opens" should be rejected 

 and that all "cut-opens" that are utilized should be emptied into 

 the hot well where their contents are boiled up again. 



Dangerous Effect of Poor Quality of Sugar. (Sweetened 

 condensed milk is not sterile. There is no part of the process 

 that would render it sterile and, from the time it leaves the 

 vacuum pan to the time when the tin cans are hermetically sealed, 

 it is exposed to contamination with microbes, even though the 

 factory observes the most rigid attention to scrupulous sanita- 

 tion and cleanliness. Most of these microbes are harmless and 

 their growth is inhibited by the preservative action of the cane 

 sugar. If, however, a poor quality of sucrose is used, which may 



