CALCULATING YIELD OF CHEESE 215 



METHOD BASED ON FAT IN MILK AND A 

 FIXED NUMBER ADDED (2) 



This method, stated in the form of a rule, is as 

 follows: Multiply the number representing the 

 per cent of fat in milk by i.i and to the result add 

 5.9. This formula was worked out at the Wiscon- 

 sin experiment station and is based upon certain 

 facts which will be briefly considered. One pound 

 of milk- fat in butter can readily hold about 0.18 

 pound of water and it can just as readily hold the 

 same amount in cheese. We multiply the per cent 

 of fat in milk by i.i instead of 1.18, because not all 

 of the milk-fat goes into the cheese. To illustrate, 

 take milk containing 4 per cent of fat; in cheese- 

 making, about 3.72 pounds of this fat in 100 pounds 

 of milk goes into cheese. This figure, multiplied 

 by 1. 1 8, equals nearly 4.40, the same as 4 multiplied 

 by i.i. In other words, the amount of fat that 

 actually goes into cheese multiplied by 1.18 gives 

 about the same result as the amount (per cent) of 

 fat in milk multiplied by 1. 1. 



The next question that presents itself is as to 

 why we add the particular number 5.9 to the fat 

 multiplied by i.i. This figure is based upon the 

 amount of cheese that can be made from 100 pounds 

 of separator skim-milk of average composition, and 

 is supposed to account for the milk-casein, the in- 

 soluble salts and the moisture not provided foi in 

 the milk-fat. It is in reality taking account of 

 casein in milk, but only of the same amount for all 

 milks. 



The inherent weak points of this method are the 

 following: (i) In the case of excessive losses of 



