COMMERCIAL TESTING OF MILK AND CREAM 245 



(3) Dirt in suspension. The amount of dirt sus- 

 pended in milk may usually be regarded as a rough 

 measure of the germ content or cleanliness of milk, 

 since the visible dirt we find in milk is generally the 

 same in source and kind. 



(4) Undesirable fermentations refer to the results 

 of the fermentation test. They may reveal themselves 

 in causing porous, spongy curd and in producing 

 offensive odors. 



(5) Number of bacteria per cubic centimeter is a 

 self-descriptive term. 



Flavor, applied to milk, is used to mean the odor 

 and taste. The abnormal odors and tastes noticeable 

 in market milk, otherwise good, come from three 

 sources : ( i ) From certain things eaten by the cow, 

 as leeks, onions, rag-weed, cabbage, etc. (2) From 

 the direct absorption of strong-smelling substances 

 present in the air surrounding the milk r such as ma- 

 nure, tobacco smoke, ensilage, etc. (3) From stable 

 filth dropping bodily into the milk. 



Testing flavor. This is done by tasting and smell- 

 ing the milk. The presence of abnormal odors can be 

 more readily perceived by heating the milk for a few 

 minutes to 100 F. in a closed bottle or jar and then 

 smelling at once on opening the vessel. 



Terms describing flavor. The following terms 

 may be used in describing the flavor of market milk: 

 (i) Perfect, (2) stable or cow manure, (3) cowy or 

 animal, (4) weedy, caused by leeks, rag-weed, etc., 



(5) vegetable, such as cabbage, turnip, ensilage, etc., 



(6) bitter, (7) fishy, (8) sour, (9) tainted. 



(i) Perfect flavor in market milk is indicated by 



