CHAPTER III 



MILK PRODUCTS 



IT is a curious fact that the quantity of cream obtained from 

 setting rich or poor milk is about the same for rich as for poor 

 milk, but the cream from the poor milk is much thinner and con- 

 tains less fat. As seen in a glass quart milk-jar, the layer of 

 cream forms almost a quarter of the bulk of the contents of the 

 bottle, at first, but after twenty-four hours or longer the layer of 

 cream becomes less, owing to the crowding together of fat globules. 

 "When cream rises in tall vessels it contains a great deal more fat 

 in its upper than in its lower layers. 



In fact, of the cream which rises in a bottle of milk, the upper 

 ounce contains as much sometimes as 25 per cent, of fat, while the 

 fat in the cream regularly diminishes until at the lowest part of 

 the layer of cream, which can be seen as a sharp line above the milk,, 

 the percentage of fat is not quite 10 per cent. The cream line in 

 bottled, pasteurized milk is apt to be poorly defined since the natural 

 clumps of fat globules in the milk are broken up by pasteurization 

 and the cream rises incompletely. This is a serious disadvantage 

 if it is desired to remove the cream for infant feeding or other 

 purposes. As we have already said, the higher the creaming tem- 

 perature the richer will be the cream, and for this reason the quantity 

 of it will be much less than from the same amount of milk which, 

 is set at a low temperature. For the lower the cream temperature,, 

 especially at the end of the creaming period, the greater will be 

 the amount of cream and the thinner will it be owins: to the ereater 

 quantity of water in it. Milk which has been watered throws up> 



54 



