234 ' SWEETENED CONDENSED MILK DEFECTS 



ance. This condition can usually be traced back to a poor qual- 

 ity of fresh milk, containing" too much acid. Very often, too, the 

 cause lies in the factory itself, where it is due to lack of clean- 

 liness. A thorough inspection of milk pipes and pumps generally 

 shows accumulations of remnants of milk which get into the 

 milk of the succeeding batch. Where this condition exists, it is 

 noticeable that the first batch of the day contains more specks 

 and lumps than the succeeding ones. These lumps do not, as a 

 rule, grow larger in size nor increase in number with the age of 

 the condensed milk, but they injure its appearance to the eye, 

 and certainly cannot add to the wholesomeness of the milk. They 

 might easily be accompanied ^ by the formation qf ptomains. 

 A more rigid inspection of all the fresh milk as it arrives at the 

 factory and thorough scouring of all milk tanks and milk pumps, 

 pipes and conveyors usually prevents the recurrence of this 

 defect. . 



Milk from Fresh Cows. During early spring there is a 

 strong tendency of the jacket and coils in the vacuum pan to 

 become coated with a thick layer of gelatinous and lumpy milk. 

 This is probably due to the fact that milk during these months 

 comes largely from freshened cows and may contain some colos- 

 trum milk which coagulates when subjected to heat, or that 

 the proteids of milk from these fresh cows are abnormally 

 sensitive to heat. This thickened material usually does not leave 

 the pan until most of the condensed milk has been drawn off. 

 It, therefore, appears in the last one or two cooling cans. If 

 the milk in these cans is mixed with the rest of the condensed 

 milk, the lumps will appear again in the tin cans. The last cans 

 drawn from the pan should, therefore, be kept separate. The 

 contents of these remnant cans may be redissolved in hot water 

 and should be recondensed in a succeeding batch. In this way 

 the manufacturer sustains practically no loss. In order to pre- 

 vent these lumps from getting into the cooling cans, some fac- 

 tories attach a strainer to the outlet of the pan. This practice 

 is as unnecessary, as it is damaging to the milk in the pan. 

 The straining greatly retards the removal of the milk from the 

 pan, and the milk is held in the hot pan so long, as to cause 

 partial superheating which is otherwise detrimental to its quality. 



