218 MARKET DAIRYING 
follows: Place the milk in a sterile double boiler and 
heat for thirty minutes at a temperature of 140° to 
145° F. Then quickly cool and keep at a temperature 
of 50° F. or below until all has been consumed. The 
lower the temperature at which the milk is kept the 
less chance for bacterial development. The milk should 
be frequently stirred during the heating process. A 
reliable thermometer is indispensible. 
MODIFYING MILK IN THE HOME. 
Where market modified milk is not available, the fol- 
lowing simple method of modifying cow’s milk for baby 
feeding may be used with good success in all homes: 
Take a quart of rich milk and pour out two-thirds of 
the contents, which will contain most of the cream; 
add water to the enriched milk, using one part water to 
two parts milk; next add a little more than two level 
tablespoonfuls of milk sugar, and neutralize the mix- 
ture by adding two to three tablespoonfuls of viscogen 
(see page 113). Now pasteurize the mixture as directed 
under “home pasteurization.” 
The amount of viscogen required to neutralize the 
milk will depend upon the acidity of the milk and the 
strength of the viscogen solution. The amount required 
can easily be determined by adding a few drops of 
phenolphthalein, dissolved in alcohol, to a small measured 
amount of milk. In the presence of acid the color of 
the milk remains unchanged, but as soon as the milk 
becomes alkaline it changes to a pink color. Standard 
lime water kept at drug stores is far weaker than 
viscogen, requiring about one part of lime water to 
neutralize two parts of milk 
If there is any tendency to constipation in feeding 
