CHAPTER XIV 



MILK, BUTTER, AND CHEESE 



Composition of Milk. Variations to which the Composition of 

 Milk is subject Effect of Individuality, Breed, Food, Time of 

 Milking, Period of Lactation. Feeding for Milk. Composi- 

 tion of Butter. Nature of the Churning Process. Effect of 

 various Foods upon the Quality of the Butter. Composition 

 of Cheese. Changes taking place during the Cheese-making 

 Process. The Ripening of Cheese. Importance of Cleanli- 

 ness in all dealings with Milk. 



Milk is not a simple substance, but a mixture of a 

 large number of different bodies which are present in 

 fairly definite quantities, though they are , subject to 

 certain variations to be discussed later. By weighing 

 out a small quantity of milk into a dish so that the milk 

 only forms a thin layer over the bottom, and putting 

 the whole into an oven to dry, we can show that the 

 greater part of milk consists of water, 'there being, as 

 a rule, not more .than 12 per cent of total solids in the 

 milk. This important figure — the amount of total 

 solids in the milk — can only be determined exactly by 

 getting the milk spread out into a very thin layer before 

 drying it, so readily does a skin form over the surface 

 and cause the drying of the rest of the milk to proceed 

 with difficulty. Among the milk solids at least three 

 are characteristic In the first place there is the fat, 

 present to the extent of 3 per cent or more; then 

 proteins to the extent of about 3§ per cent, the greater 

 part of which is commonly called casein ; then lactose or 



