Enough rennet should be added, as a rule, to cause thickening of the
milk to begin in 20 minutes, at 82 degrees. More or less rennet may be
used, as it is designed to have cheese cure more or less rapidly. As a
rule, the more rennet is used, the lower should be the temperature at
which the milk is set and the curd worked. Agitation of the milk should
be kept up for at least 15 minutes, where coagulation begins in 20
minutes, or as long as it can be and not prevent a solid coagulation.
The stirring after the rennet is incorporated is merely to keep the
cream from rising. The less cream gets to the surface, the less waste
there will be. In a cool room, where the surface cools quickly and
there is a falling of the temperature of the milk, there will be a thin
cream on the surface. This will form a soft cream curd, which will
adhere to the sides of the vat, to the rake, and to the hands, and be
quite annoying. The amount is trifling, but the annoyance of the thing
is enough of itself to make it desirable to keep the cream down; and a
summer temperature of the room is useful for this purpose, aside from
the comfort and the better handling of the curd, from first to last.