172 MARKET DAIRYING 
whey previously prepared. This will make the com- 
position approximately correct so far as fat and pro- 
tein are concerned. But the milk is deficient in sugar 
as human milk contains about 25% more sugar than 
cow’s milk. The deficiency in milk sugar is made up 
by adding commercial milk sugar. Milk sugar is speci- 
fied because it is more digestible than cane sugar. 
It will be remembered that human milk has an alka- 
line reaction while cow’s milk is decidedly acid. It is, 
therefore, advisable to add some lime water in modify- 
ing milk. Enough should be added to make the milk 
practically neutral. 
The best lime preparation for reducing the acidity of 
milk is “viscogen,” the preparation of which is discussed 
on page 113. Sugar has a great solvent action on lime 
and hence its use makes possible a very concentrated 
lime solution. 
The milk to which the cream and sugar has been 
added, should not be mixed with the whey until the 
latter has been heated to 145° F. for ten minutes, or 
long enough to destroy the action of the rennet extract 
remaining in it. As soon as the rennet has been de- 
stroyed, the prepared milk is added to the whey and 
thoroughly mixed. Next the acidity is reduced by add- 
ing the viscogen prepared for this purpose. This done, 
the mixture is pasteurized at 145° F. for thirty minutes 
and then quickly cooled to a low temperature when it 
is ready for market. 
The foregoing suggestions regarding the modifying 
of milk for infants can easily be followed by anyone 
and milk so modified can be sold at a profit by charg- 
ing only slightly more for it than for ordinary market 
mill. 
