168 MARKET DAIRYING 
also to fresh, unpasteurized cream, though to a less 
extent. Sweet, fresh cream after it leaves the separator 
has little body and such cream should be held at least 
four hours close to the freezing temperature before 
freezing. But here as in the case of pasteurized cream, 
the time of aging at low temperatures before freezing 
should be limited to twenty-four hours. 
While prolonged aging may slightly increase the body 
of the cream and, therefore, make possible a larger 
yield than can be obtained by aging cream six to twenty- 
four hours, the advantage thus gained is more than off- 
set by the extra cost and labor involved in the extra 
holding and by the depreciation in the flavor due to 
bacterial development. Cream always contains bacteria 
capable of developing at freezing temperatures and the 
longer the cream is kept the more the flavor will suffer. 
Indeed there is actual danger in prolonged holding of 
cream at low temperatures because of the possible de- 
velopment of toxic substances. Every year many per- 
sons are poisoned by eating ice cream and such poison- 
ing is usually ascribed to prolonged holding of insani- 
tary cream at low temperatures. 
What is said here about holding cream before freez- 
ing applies with equal force to cream after freezing. 
Hardening after freezing is essential, but there is no 
reason why this process should be extended beyond 
twenty-four hours. Ice cream will be better twenty- 
four hours after freezing than when kept longer. 
The Use of Condensed Milk: A great many _ ice 
cream manufacturers use condensed milk in making ice 
cream. Some use as much as eight per cent. Condensed 
milk gives body to ice cream. 
