New York AGRICULTURAL EXPERIMENT STATION. 91 
the casein is nearly all in the form of dilactate at the time the 
milk has set in a solid mass. 
It was desired to determine the amount of casein monolactate 
in milk before the milk visibly coagulates. For studying this 
point, some milk was set aside one day at 5 p. m., and the next 
forenoon was warmed to about 104° F. (40° C.), when casein 
monolactate separated from the milk. In this case, 65 per ct. 
of the casein was in the form of monolactate, while no dilactate 
was present. 
The method employed by us in separating casein, casein mono- 
lactate and casein dilactate, when they occur together in milk, 
is as follows: The milk is heated to 104° F. (40° C.) and the mono- 
lactate and dilactate separate as a precipitate. When only casein 
and casein monolactate are present, filtration serves to separate 
them. When the two lactates are present in the coagulum formed 
after heating, they are removed from other milk constituents by 
filtration and the monolactate is dissolved in a 5 per ct. solution 
of sodium chloride at about 130° F. (55° C.), when the two com- 
pounds are separated by filtration. 
CONDITIONS OF MANUFACTURE IN RELATION TO THE YIELD AND COM- 
POSITION OF COTTAGE, OR DUTCH, CHEESE. 
The names, cottage cheese and Dutch cheese, are applied to the 
product made by allowing milk to stand until it coagulates by 
ordinary souring, the curd being drained to allow the escape 
of much of the whey, after which it is salted, pressed into the 
form of balls, and is then ready for consumption. The souring 
is often hastened by adding a little sour milk or other “ starter.” 
In commercial manufacture on a large scale, a “ starter ” is used 
and also a small amount of rennet extract is added to the partially 
soured milk in order to hasten its coagulation and save time in 
the process of manufacture. Skim-milk is commonly employed 
in making cottage cheese. When whole milk is used, so much of 
the fat is lost in. the whey that the process is a very wasteful 
one. It is good economy to use separator skim-milk and then 
to mix cream with the cheese when it is salted, if it is desired 
to have fat in the cheese. In this way, the fat can be more 
economically incorporated and its amount in the cheese kept 
under better control. 
