214 SCIENCE AND PRACTICE OF CHEESE-MAKING 



factory by factory, were very uniform, being very 

 close to 2.72 pounds of cheese for one pound of fat 

 in milk. The individual results giving the average 

 varied widely, from 2.51 to 3.11. These extreme 

 variations were due to wide variations in the water 

 content of the cheese rather than to variation in 

 the real relation of fat to cheese yield proper, as 

 we have pointed out in the chapter preceding. Based 

 on a uniform percentage of water in cheese, the va- 

 riations would be within much less wide limits, 

 ranging from 2.61 to 2.89. This variation was due 

 mainly to variation in the relation of the fat and 

 casein in the milk and, in some cases, to excessive 

 losses experienced in the process of cheese-making. 

 The average result (2.7) is based upon milk con- 

 taining 3.75 per cent of fat, 2.46 per cent of casein 

 and upon cheese containing nearly 37 per cent of 

 water. The ratio of milk-fat to casein is, therefore, 

 I ;o.665. When the ratio of fat and casein varies 

 widely from this, we shall get more or less cheese 

 than that called for by the rule. Thus, in milk in 

 which the casein is high in relation to fat, as often 

 happens in milk low in fat, the formula gives too 

 low results (p. 207) ; while the reverse is true in 

 case of milk high in fat in relation to casein, as 

 often happens in milk rich in fat (p. 209). There- 

 fore, as a result of the variations of the relation of 

 fat and casein in cheese-factory milks, we may ex- 

 pect this method to give results varying from the 

 actual yield of cheese, in extreme and uncommon 

 cases, to an extent equal to 0.5 to 0.75 pound of 

 cheese for 100 pounds of milk. When the variation 

 is greater than this, it is usually due to excessive or 

 deficient amounts of water in cheese. 



