SWEETENED CONDENSED MILK DEFECTS 245 



Contaminated Sugar. The sucrose itself may be contam- 

 inated with yeast. This is frequently the case and especially so 

 if the sugar is exposed to dampness, and if flies, bees, ants or 

 cockroaches have access to it. 



Again, the sugar may reach the milk through a sugar chute. 

 The lower end of the chute is usually located directly over the 

 steaming milk in the hot well. The vapors arising from below 

 may be condensed in the chute, causing its inside walls to be- 

 come damp, and sugar will adhere to the damp surface, forming 

 a crust. If the crust is not re/noved daily, its contamination with 

 yeast and other dangerous micro-organisms is almost inevitable 

 and whenever this crust peels off and drops into the milk, the 

 contamination may be carried into the finished product, giving 

 rise to gaseous fermentation. 



Contaminated Machinery and Milk Conveyors. Remnants 

 of milk may lodge in the condenser, in the vacuum pan, in the 

 pipes conveying the milk and condensed milk, in the cooling 

 cans or coils, in the supply tank of the filling machine, or the 

 filling machine itself. These remnants are all subject to con- 

 tamination and may become the source of fermented condensed 

 milk. The strictest attention to scrupulous cleanliness and con- 

 tinuous inspection of all parts of conveyors and apparatus which 

 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 succeeding batches. If 

 these samples happen to be contaminated with the fermenting 

 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 



