130 PLAIN CONDENSED BULK MILK 



many of the more efficient types of milk and cream pasteurizers 

 could be used to excellent advantage for this purpose. 



It is advisable, however, to heat this milk only to about 150 

 to 160 degrees F. in order to secure a nice "liver" (coagulum), 

 when it is superheated in the pan. If the milk is heated to the 

 boiling point in the forewarmers, it does not respond to the super- 

 heating in the pan as satisfactorily. 



Condensing. The condensing of plain condensed bulk milk 

 is done in the vacuum in a similar manner as described under 

 evaporated milk, except that the evaporation is carried farther. 

 See also Chapter XIV on "The Continuous Concentrator," pages 

 133 to 141. 



Superheating. When the condensation is nearly completed 

 the milk in the pan is superheated. This is accomplished by 

 shutting off the steam to the jacket and coils, closing the valve 

 that regulates the water supply of the condenser, stopping the 

 vacuum pump and blowing steam direct into the milk in the pan, 

 for the purpose of swelling and thickening it. During this 

 process the temperature rises to between 180 and 200 degrees 

 F. When the milk has become sufficiently thick or, in the lan- 

 guage of the processor, has produced the "proper liver" (coagu- 

 lum) the steam is shut off, water is again turned into the con- 

 denser 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 degr. F. the process is 

 complete, the vacuum is released and the condensed milk is 

 drawn off. The superheating usually occupies 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. 



