254 REPORT OF THE DAIRY DEPARTMENT OF THB 
rennet test, the showing required in the test cup being four 
spaces. This indicates an acidity which, under our conditions, 
will mature the curd sufficiently for drawing the whey in about 
two and one-half hours. With such an amount of acid at the 
start, the curd will, at the end of the time given, show one-eighth 
inch fine threads upon the hot iron. 
In very few cases was the milk sufficiently “ ripe ” immediately 
after heating to secure the best results as we handle it; there- 
fore, carefully prepared sour milk was added in moderate quan- 
tity. By this method the milk in a very short time reaches the 
acidity required. We believe that, when the milk does not con- 
tain quite enough acid, the addition of a sufficient amount of 
sour milk to secure the proper degree of ripeness quickly is much 
more satisfactory and safe than holding the milk until the acid 
develops normally. If gas-forming bacteria are present in abund- 
ance, holding the milk allows them to increase and doubles the 
liability to “ gassy” curd. As soon as the milk shows proper 
conditions by the Marschall test, rennet is added at the rate 
of 24 ounces to 1,000 pounds of milk, this amount of good rennet 
extract being sufficient to coagulate properly ripened milk so 
that, with intelligent handling of the curd, the loss of solids 
is aS small as possible. 
The curd is cut in about 30 minutes from the time the rennet 
is added, using care to have the pieces of curd uniform in size 
and fine enough to make a proper separation of moisture easy. 
The stirring of the curd commences as soon as the cutting is 
completed and continues, without increasing the temperature, 
until the separation of water from the curd is well started. The 
heat is then gradually increased, taking about one hour to reach 
the extreme of 98° F. If at this point there is a sufficient sepa- 
ration of water from the curd, so that the latter has a firm ap- 
pearance and has reached such a stage of contraction that it does 
not pack, and the heat is uniform throughout the mass, the vat 
is covered and allowed to stand, the curd being occasionally 
stirred to prevent matting together and to keep it even through- 
out. Under these conditions, with proper acidity at the start, 
