166 CITY MILK SUPPLY 



TABLE 49. CONTAMINATION OF PASTEURIZED MILK BY THE BOTTLING MACHINE 



(PRUCHA) 



bacterial content of 2,558 per cubic centimeter. In the milk room, the 

 milk was poured through a strainer out of which it ran through about 20 

 ft. of sanitary pipe to a clarifier tank, thence through the clarifier, thence 

 over an open tubular cooler into cans from which it was poured into a 

 four-valve bottler. When all of these utensils were sterile the bottled 

 milk had a bacterial count of but 3,875 per cubic centimeter which meant 

 that there was an increase in bacteria attributable to the utensils of but 

 about 1,300 bacteria per cubic centimeter. In contrast to this when the 

 utensils through which the milk passed were carefully washed but were 

 not sterilized, the milk had a bacterial count of about half a million. 



Table 49 showing the test of the bottler in a sterile and in an insterile 

 condition with pasteurized milk. In a sterile condition the first and 

 fifty-fourth bottles had the same bacterial count but when the bottler 

 was merely carefully washed previous to beginning bottling, the milk in 

 the first bottles filled showed a higher bacterial count than the raw milk 

 and it was calculated that when the bottler was not sterilized it added 

 4 billion bacteria to the 300 qt. of milk bottled. 



The results of this extensive investigation are convincing evidence 

 of the highly important part that milk utensils play in contaminating 

 market milk. Milk in the course of its progress from the farm to the 

 consumer is thoughtlessly poured from container to container and yet 

 a little reflection would lead one to conclude that milk must pick up dirt 

 and germs from unclean and insterile vessels of all sorts with which it 

 comes into contact. Such being the case, the pollution derived from 

 utensils becomes impressive. 



Wherever piping is used to conduct milk about a dairy, it should be 

 of the type catalogued as "sanitary." It is seamless and the fittings 

 make a smooth joint. Even this kind is difficult to clean. It should be 

 taken apart at least twice a day and when not in constant use oftener, 

 for the lengths to be scrubbed out with long brushes and sterilized. 



Acid-forming bacteria are the principal ones that get into milk from 



