164 



PLAIN CONDENSED BULK MILK 



ess the temperature rises to 

 between 180 and 200 de- 

 grees P. When the milk 

 lias become sufficiently 

 thick or, in the language 

 of the processor, has pro- 

 duced the "proper liver" 

 (coagulum) the steam is 

 shut off, water is again 

 turned into the condenser 

 and the vacuum pump is 

 started up. As soon as the 

 vacuum has risen to from 

 twenty-five to twenty-six 

 inches and the temperature 

 has dropped to about 130 

 degrees F. the process is 

 complete, the vacuum is 

 released and the condensed 

 milk is drawn off. The 

 superheating usually oc- 

 cupies about twenty-five 

 to thirty minutes. 

 The completion of the superheating, or the point when the 

 superheating should cease, may also readily be detected by the 

 examination of a sample of the product. As soon as the con- 

 densed milk begins to show a flaky condition of the curd, the 

 purpose of superheating has been accomplished. The amount of 

 superheating necessary and that the milk will stand, will largely 

 depend, aside from the sweetness of the original milk, on the 

 extent of the concentration. The higher the ratio of concentra- 

 tion, the less superheating is required to secure the desired 

 results. 



Striking. -The striking, or sampling and testing for gravity 

 is dorie-wfrK k Beaume hydrometer, the same, or a similar one, 

 as is used for evaporated milk. The scale should extend to 18 

 degrees Beaume. The batch should be struck before and after 

 superheating. 



Factories which standardize their product to a certain estab- 



Fig-. 72. Superheater 



Courtesy of C. E. Rogers 



