164 PLAIN CONDENSED BuLK Mu1,K 
ess the temperature rises to 
between 180 and 200 de- 
erees I. \When the milk 
has 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. 
(orca 
Fig. 72. Superheater 
Courtesy of C. BE. Rogers 
The completion of the superheating, or the point when the 
supérheating 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 done with a Beaumé hydrometer, the same, or a similar one, 
as is used for evaporated milk. ‘The scale should extend to 18 
degrees Beaumcé. The batch should he struck before and after 
superheating. 
Factories which standardize their product to a certain estab- 
