156 



CITY MILK SUPPLY 



acquire an off flavor; sometimes the operation of a gasolene engine where 

 the cooling is being done will impart a distinct taste to the milk. 



Aeration of Milk. Formerly much store was set by aeration as a 

 method of removing odors from milk and in improving its keeping quality 

 but it is now known that milk from healthy cows which have been prop- 

 erly fed and that is drawn in a place free from stenches has no disagree- 

 able smell. Furthermore such improved keeping quality as resulted 

 from aeration is now attributed to the cooling of the milk in the process. 

 So this fetish is not so fashionable among dairymen as it once was. Such 

 aeration as milk now receives it generally gets in the process of cooling 

 but that aeration of first-class milk is not necessary is shown by some of 

 the best certified milk being bottled warm and cooled afterward. When 

 warm milk is put into cans and the covers put on, it sometimes happens 

 that bad flavors develop but this is believed to be due to bacterial growths 

 that are favored under such conditions because the milk has not been 

 properly cooled rather than because the milk was not aerated. 



Sometimes milk may be improved by aeration. Ayres and Johnson 

 have pointed out that the garlic flavor so common in milk in some locali- 

 ties where the animals eat the wild onion in pasture, may be removed 

 from milk and cream by heating them to 145F. and blowing air through 

 under pressure. 



Barn Practices in Relation to Milk Quality. The attempt has been 

 made to estimate the relative importance of the common barn practices 

 in contaminating milk. Stocking in Bulletin 42 of the Storrs Agricul- 

 tural Experiment Station published observations on the effect at milking, 

 of feeding cows, of brushing them, of wiping them with a damp cloth, 

 of rejecting the fore-milk and of trained as compared with untrained 

 milkers. The results of his study are presented in Table 44. 



TABLE 44. THE EFFECT ON THE BACTERIAL COUNT, OF FEEDING, OF BRUSHING, OF 

 WIPING Cows. AND OF REJECTING FORE-MILK AT MILKING (STOCKING) 



