GASES OF MILK 21 



who do not own much land, graze their cows along the roads 

 where weeds of different kinds grow. Milk from such cows has a 

 peculiar characteristic odor or taint. In this country it~is-R. 

 common occurrence to find that milk delivered by patrons who 

 keep their cows on timber-land pastures has a peculiar weedy 

 odor. Especially is this true in the fall or late summer. If such 

 milk is heated to 160 to 180 F., and stirred occasionally, some of 

 these taints pass off. The addition of a small amount of saltpeter 

 will improve the flavor of milk where such foods as turnip and 

 sugar-beet tops are fed. This remedy is often applied to milk in 

 Canadian cheese factories, during the fall of the year when turnip 

 tops are fed, and also in Germany during the period of the feeding 

 of sugar-beet tops. 



Too much emphasis cannot be placed upon the food that 

 the cows receive. While it is true that much of the desirable 

 aroma and flavor in butter is due to bacterial growth, the kind 

 of food fed to cows is not without significance. It is a well-known 

 fact that districts such as Normandy and Denmark, which have 

 become famous for their high quality of dairy products, have the 

 best of pasture and winter feeds. 



Besides the kind of food, some physiological disturbances of 

 the cow may cause abnormal taints in milk. 



(2) Gases or taints which are formed in the milk or absorbed 

 by it are due to fermentation and absorption respectively. The 

 former cause will be considered in a separate chapter, and the 

 latter cause needs little explanation. It is a well-known fact 

 that milk and most of its products have the special property 

 of absorbing odors which may be present in their surroundings. 

 For this reason, milk, as well as other dairy products, should at 

 all times be kept in clean utensils and pure surroundings. 



Taints appearing in milk immediately after milking are due to 

 absorption within the cow. Taints that develop on standing are 

 due to bacterial growth in the milk, or to absorption from impure 

 surroundings. In the prevention and removal of taints from 

 milk the first step is to remove the cause, and the second to 

 eliminate as many of these taints as possible by a process of 

 aeration or pasteurization. 



