SANITARY MILK PRODUCTION 



165 



thoroughly; in large plants this is done by a hot-air blast. If one is not 

 used, unless the utensils are carefully drained, milky puddles from the 

 condensed steam collect in them and soon support rich bacterial growths. 

 On the farm after scalding or boiling, utensils are usually wiped with a 

 cloth; it should either be new, or one that has been boiled and dried 

 quickly. Bacteria multiply in cloths so long as they are wet, and the 

 good effect of boiling utensils is often entirely destroyed by wiping them 

 afterward with a cloth that supports a rich growth of germs. Sunlight 

 has a strong disinfecting action and for that reason it is good to sun the 

 tinware on a rack out of doors in a place free from dust and protected from 

 flies. In the dairy, the utensils should be kept in a well-aired place free 

 from strong odors and they should be inverted so that no dirt can fall 

 into them. 



Prucha of the University of Illinois Station has for some time been 

 studying the microbial contamination of milk by utensils. He has given 

 out a few of his results; a brief statement of them is found in Tables 47, 

 48 and 49. 



TABLE 47. THE BARN AS A SOURCE OF BACTERIAL CONTAMINATION OP MILK 



(PRUCHA) 



TABLE 48. UTENSILS AS A SOURCE OF BACTERIAL CONTAMINATION OF MILK (PRUCHA) 



Bacteria per cubic 

 centimeter 



All utensils sterile 



Milk leaving barn 



Same milk bottled 



Only bottles sterile 



Increase due to three pails 



Increase up to clarifier 



Increase due to clarifier 



Increase due to cooler 



Increase due to bottler 



Total increase in bottled milk . . 



2,558 

 3,875 



57,077 



15,353 



172,763 



19,841 



247,611 



515,200 



Table 47 shows the bacterial content acquired by the milk from the 

 udders of the cows and the various barn influences to which it was 

 exposed in being milked into a sterile pail. 



As regards Table 48 the milk was brought by the milkers in their 

 pails to the milk room in the barn where it was found to have an average 



