Milk and Its Products. 291 



Standard. Whole milk or full cream cheese contains, in the 

 water-free substance, not less than 50 per cent of butter fat. 



The term "full cream" simply means that in the manufacture, 

 whole milk has been used. It gives the impression that cream 

 has been added, but such is not the case. 



In some cases, cheese is adulterated by the addition of foreign 

 fat, as lard. Such cheese is usually known as "filled" cheese. 



Whey. As already stated, whey contains almost all of the 

 milk suga.r and albumin originally present in the milk, as well 

 as a portion of the ash. The amount of fat in the whey will de- 

 pend upon the treatment the curd has received. If the milk has 

 been rich, the temperature of cooking high, and the curd roughly 

 handled, considerable quantities of fat will be present. Where 

 whey is rich in fat, it is customary to recover it for the manu- 

 facture of whey butter, either by allowing it to rise by gravitj^ 

 or through the use of the separator. The average composition 

 of whey is about as follows : Water, 93.3 per cent ; protein, 0.9 : 

 fat, 0.3 ; sugar, 4.9 ; ash, 0.6. 



The cheese yield of milk. As has been seen, the two milk con- 

 stituents that must determine the yield of cheese are casein and 

 fat. The percentage of these varies in milks from different in- 

 dividual cows. They are not always in the same relation in two 

 different milks. Milks of high fat content are not proportionately 

 richer in casein than milks of low fat content. As a rule, for 

 100 pounds of fat in Jersey and Guernsey milk, one may expect 

 55 to 65 pounds of casein, while in the milk from the Ayrshire 

 and Holstein breeds, there will be 65 to 75 pounds. There will 

 be individual exceptions to this general statement. 



In herd milks, although the relation of casein to fat is more 

 constant, nevertheless variations in the proportion of these two 

 constituents exist. The general rule that high fat milks do not 

 yield in proportion to their fat, as much cheese as low fat milks, 

 finds its explanation in the fact that high fat milks have pro- 

 portionately less casein. This is illustrated in the following 



