State Dairy Association. 77 



In order to handle milk intelligently, it is necessary to under- 

 stand the causes of these odors and tastes, and to assist in this 

 effort, it is helpful to classify the sources under three heads: 



1. Absorption from the air. 



2. From the cow herself. 



a. Feed. 



b. Sickness. 



3. From the action of bacteria. 



a. Souring. 



b. Gassy. 



c. Putrifactire. 



d. Slimy. 



e. Bitter. 



Odors from the air — The absorption of odors from the air is a 

 common occurence as every one knows, and so far as I know in no 

 case are the odors absorbed, beneficial. Milk, cream and butter 

 absorb odors readily, but cheese very slowly. On account of this 

 characteristic of milk it is necessary at all times to guard against 

 exposing milk or cream to any odor. This means that the barn 

 and surroundings must be free from odors. It was formerly 

 thought and even taught in the dairy schools, that milk would not 

 absorb odors as long as it was warmer than the atmosphere, but 

 scientific experiments showed this to be a mistake, and in fact that 

 the reverse is true. Warm milk absorbs odors faster than cold. 



Every retailer knows that he is often blamed for odors and 

 tastes which are absorbed from the refrigerator where the milk is 

 placed by the consumer. The odors of fruit are especially easy o<! 

 absorption by butter and milk. Injurious effects of odors from 

 absorption are small compared with the injuries from the third 

 class, the bacteria. As soon as milk is taken from the source of 

 the odors, the odors begin to evaporate and are less pronounced 

 after a time. An absorbed odor may usually be driven off entirely 

 by heating from 130 to 170 degrees. 



From the cow — The second source of taints in milk is the cow 

 herself. These are of about equal importance with the first class 

 mentioned. The most common of these are the tastes produced by 

 certain feeds. As a rule the tastes due to this source are objection- 

 al, although not necessarily so. Just how much ordinary feed 

 effects the taste of milk we cannot say definitely, but probably the 

 effect is slight. Silage, as usually fed, gives milk a slightly char- 

 acteristic taste which, however, is not objectional and in fact is 

 liked by nearly all milk customers. If people be given milk from 



