254 CITY MILK SUPPLY 



ing poor service being much older than that from nearby stations. The 

 U. S. Department of Agriculture in 1914 found that the extremes in the 

 age of the milk were 2 to 40 hr. in Washington, 4 to 16 hr. in Baltimore, 

 4 to 41 hr. in Philadelphia, 2 to 48 hr. in Boston and 4 to 40 hr. in Pitts- 

 burgh. The average age of the milk in the several cities is considerable 

 under the maxima given. It is considerably higher in Philadelphia, 

 Boston and Pittsburgh than in Washington and Baltimore because to the 

 first three of these cities the milk comes from a greater distance and also 

 because much of it goes through country milk plants. In Washington 

 and Baltimore the refrigerating facilities in transit are poorer than they 

 are for the other cities, hence the milk has to be fresher. In Philadelphia 

 practically all of the milk is less than 30 hr. old on arrival. In Boston the 

 milk that was 48 hr. old was but part of the supply of a single dealer. 



In considering the age of milk it must be remembered that it is im- 

 portant, only because milk spoils as it grows old. Milk that is 24 hr. old 

 is expected to be more decomposed than that 12 hr. old but in fact this is 

 not always so. The decomposition of milk is effected by living or- 

 ganisms over which man has a certain amount of control for by taking 

 pains he can limit the number that get into milk and by cooling it suffi- 

 ciently he can arrest their growth and so retard the decomposition of the 

 milk or in a sense prevent its ageing. A dirty milk y shipped in dirty cans, 

 in a poorly iced car may age more in 12 hr. than a clean milk, in clean cans, 

 in properly cooled cars may in 16. 



Tasting the Milk. When milk is delivered in bulk at the plant for 

 preparation for the market, it is usually tasted and often is sampled to 

 determine the sediment, the butterfat and perhaps the bacterial content. 

 Some tasters take the milk into the mouth; others simply shake the cans 

 vigorously and removing the cover quickly, take the odor. By either 

 method unpleasant flavors and high acidity are detected with consider- 

 able certainty. Milk that is found off flavor is rejected; thus dealers are 

 protected from complaining customers and from paying for milk that is 

 unsaleable. Still, because bacterial growths develop in the milk after it 

 has passed the tasters, it sometimes reaches the consumer with a disagree- 

 able flavor. In the past, certain abuses were common in tasting and sam- 

 pling the milk. Tasters drank from the cans or their covers, or tasted 

 from spoons or ladles that without washing were used to stir and taste 

 other cans; milk in the cans was in one way or another brought into 

 contact with the hands and other insanitary practices were indulged in. 

 Nowadays this sort of thing does not occur in the better plants but else- 

 where it still persists. 



Drip Pans. After the cans of milk have been tasted and sampled 

 they are dumped into the mixing vats, and the cans inverted over a drip 

 pan so that the drainage may be caught and saved to be used in dairy 

 manufactures. 



