RENNET AND RENNETING. l6l 



degrees each decrease of I degree in temperature 

 increases the time for coagulation by one to two 

 minutes. Adding the rennet to milk at a temperature 

 of 80 degrees causes an extra loss of fat in the whey, 

 although it appears to make little or no difference in 

 the quality of the cheese. 



An increase from one to two ounces per 1,000 

 pounds milk decreases the time for coagulation by 

 about one half hour. An increase from two to three 

 ounces per i,coo pounds milk decreases the time 

 required for curdling by about ten minutes. Increas- 

 ing the quantity of rennet from three to four ounces 

 per 1,000 pounds milk decreases the time by about 

 seven minutes, and from four to five ounces the time 

 is decreased by about three minutes. 



Rennet acts somewhat slowly, causing gradual pre- 

 cipitation of the casein unless the milk be very ripe. 

 The firmness of the curd depends upon the percentage 

 of fat in the milk, the acidity, of the milk at the time 

 of adding the rennet, the temperature of the milk 

 during coagulation, the length of time which elapses 

 after the rennet has been added, and upon the strength 

 of the rennet. If less than about three ounces of 

 standard rennet (such as Hansen's) per 1,000 pounds 

 milk be used, the curd does not appear to retain so 

 large a portion of the fat in the milk as it otherwise 

 could do, hence less than this quantity should not 

 be used. Some makers economize on rennet at the 

 expense of the yield of cheese. The average percent- 

 age of fat in the whey when using but from one to 

 two ounces of rennet per 1,000 pounds milk is from 



