GASES OF MILK 21 



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

 where weeds of different kinds grow. ]\Iilk from such cows has a 

 peculiar characteristic odor or taint. In this country it is a 

 common occurrence to Imd that milk deliA'ered b}' patr(jns who 

 kee[) their cfjws on timber-land pastures has a jjeculiar weed}' 

 odor. Especiall}' is tills true in the fall or late summer. If >uch 

 milk is heated to i6o'' to iSo ' F.. and stirred occa^ionalh", S(jme uf 

 these taints pa>s off. The addition of a small amount of saltjjeter 

 will imjirow the ikiA'or of milk where such foods as turnip and 

 sugardjeet tops are fed. This remed}- is often ajjplied to milk in 

 Canadian cheese factories, during the fall of the year when lurni)) 

 top.^ are fed, and abo in German}" during the jx-riod of the feeding 

 ol sugar-beet tops. 



l"oo much emphasis cannot be placed upon the food that 

 the cows receiA'c. \\'hile it is true that much of the desirable 

 ar(jma and lki\'or in butter is due to bacterial grijwth, the kind 

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

 fact that districts such as Xormand}' and Denmark, which ha\'e 

 fjecome famous f(jr their high quality of dair\- products, ha^'c the 

 best of pasture and winter feeds. 



Besides the kind of ff)od, some phA'siological disturbances nf 

 the cow ma}- cause abnormal taints in milk. 



(2) (iases or taints which are formed in the milk or absorljcd 

 bv it are due to fermentation and absorption respectiA'el}-. The 

 f(jrmer cause will be considered in a separate chapter, and the 

 latter cause needs little explanation. It is a welbkmiwn fact 

 that milk and most of its products have the special ijrojjert}- 

 of absorbing odors which ma}' be present in their surround iuL^^. 

 For this reason, milk, as well as other dair}- products, should at 

 all times be kept in clean utensils and pure surnjundings. 



Taints appearing in milk immediately after milking are due to 

 absorption within the cow. Taints that de^"elop on standing are 

 due to liacterial growth in the milk, or to absorption from imijure 

 surroundings. In the pre%'ention and removal of taints from 

 milk the first step is to remove the cause, and the sec(jnd to 

 eliminate as man}- of these taints as possible b}' a i")rocess of 

 aeration or i:)asteurizati<.)n. 



