172 TWENTY-FIFTH ANNIVERSARY REpoRT. 
and of casein in milk. A closer approximation to cheese yield from 
any given normal milk can be found when the amount of fat and 
of casein is. known.’ Multiply the percentage of fat in milk by 1.1 
and the percentage of casein by 2.5 ;,add the two products. 
This rule can also be applied to normal milk, when only the per- 
centage of fat in milk is known, by first using the following rule to 
ascertain the amount of casein in milk: Subtract 3 from the per- 
centage of fat in milk, multiply the result by 0.4, and add this result 
to 2.1. This rule is based upon our work embodied in Bul. 110. 
(7) Losses of milk constituents in the manufacture of cheese — 
The yield of cheese from milk depends, of course, upon the amount 
of milk constituents lost in the process of cheese-making. Under 
normal conditions of manufacture, about 83 pounds of the water 
present in 100 pounds of milk go into whey and along with it most 
of the albumin and sugar and soluble ash. These losses are normal 
but the losses of fat and casein require special consideration. 
(a) Loss of fat. In the several hundred experiments made by 
us in cheese-making, the amount of fat lost in whey varies from 
0.20 to 0.50 pound and averages 0.33 pound for 100 pounds of 
milk. Of the fat in factory milk, from 86.5 to 94.3 per ct., with an 
average of 91.2 per ct., goes into cheese, while 5.7 to 13.5 per ct., 
with an average of 8.8 per ct., goes into whey. The amount of fat 
lost is practically independent of the amount of fat in milk, as 
shown by the results embodied in the following table :9 
TABLE V.— Loss oF Fat. 
—C__—_—____—_——————————————— ee 
oe voghttin in whey for an: 
experiments. eee oe poe in whey. 
Lbs. Lbs. Per ct. 
22 3.0 to 3.5 0.32 9.55 
112 3.5 to.4.0 0.33 8.33 
78 4.0 to 4.5 0.32 reis 
16 4.5 to 5.0 0.28 5-90 
7 5:0 to 5.25 0.31 6.00 
——— eee 
The belief universally held by cheese-makers previous to fifteen 
years ago to the effect that all fat in milk over 3.5 per ct. is inevi- 
* Bul. 60, p. 514. 
* Bul. 68, p. 214. 
. 
4 
a 
3] 
