CHEDDAR CHEESE. 55 
cool it down, for the milk will be ripening while we delay set- 
ting it. The only objection to setting milk at 90° is that the 
eurd hardens too fast to cut it conveniently. If it were not for 
that fact there would be no objection to setting it at 98°. 
There is nothing to be gained by setting milk at 82° and 
waiting for it to curdle. If milk is over-ripe time can be gained 
by setting it at as high a temperature as it can be readily 
handled. 
For a fast-curing cheese we should use enough rennet to 
curdle the milk in fifteen to twenty minutes; and for a slow-cur- 
ing cheese enough to curdle it in thirty to forty minutes. 
117. Rennet Should be Diluted. 
The rennet should be diluted, not with milk (why?) but 
with a dipperful or pailful of water, and then poured into the 
vat evenly from one end to the other. The water should te 
about 90° F. If above 100° F. the rennet will be weakened 
(74). The milk should be thoroughly stirred just previous to 
adding the rennet, and the rennet thoroughly mixed with the 
milk. The stirring should be done gently so that the fat will 
not separate from the milk. 
The milk should be kept in motion for several minutes; the 
surface should then be stirred gently with the bottom of the 
dipper so that the cream will not rise on the surface, and the 
milk will set, or coagulate, and hold it down. The movement of 
the dipper should be kept up for about half the time it takes 
the milk to coagulate, and then a cover should be put over the 
vat to keep the surface of the milk from cooling off. 
118. The Use of Pepsin. 
In substituting pepsin for rennet, only scale pepsin of a 
strength of 1-3000 should be used. Use a weighed quantity of 
pepsin at the rate of .5 gram for every hundred pounds of milk 
in the vat, or for a slow-curing cheese at the rate of .4 gram. 
Dissolve it in cold water before adding to the milk. Pepsin can 
be obtained in pound or smaller bottles from dairy supply 
houses. A pound is énough for 100,000 pounds of milk. 
119. When the Curd is Ready to Cut. 
The curd is ready to cut when it will break clean before the 
finger. The index finger is thrust into the curd and pushed 
