ROPY MILK. 33 



with the milk. Unclean utensils constitute the greatest factor 

 in the contamination of milk. The wire mesh strainer, parti- 

 ally clogged with filth, may be the only visible evidence of 

 carelessness. Bacteriological examination of the supposedly 

 clean utensils will reveal the presence of ropy milk organisms 

 in a large percentage of examinations. This is most readily 

 done by pouring separate samples of sterilized milk into the 

 various suspected utensils and then immediately out again. 

 These samples kept at a low temperature for several days will 

 become viscid if they have been in contact with the bacteria 

 of ropy milk. Attention to the technic of washing utensils 

 will reveal the fact that the scalding is not carried out in accord- 

 dance with the bacteriological requirements governing the prac- 

 tice. Carelessness in this regard is by no means limited to 

 farmers with poor scalding equipment. It is just as frequently 

 the result of too hasty steaming of cans by employees in large 

 city concerns, who misuse the abundant facilities for scalding 

 at their disposal. Gross neglect, therefore, permits the ropy 

 milk organisms to exist in milk utensils from day to day, to con- 

 taminate each succeeding lot of milk. Under such conditions 

 the mill^ strainer, designed to improve the quality of milk, 

 becomes a potent factor in its deterioration. 



Means of corn-bating ropy milk. The control of this milk 

 fault is a comparatively simple matter when bacteriological 

 principles are borne in mind. In most cases the trouble may 

 be abated by instituting the continued practice of a thorough 

 scalding of every utensil with which milk comes in contact. 

 In the absence of steam, immersion in boiling water for three 

 to five minutes will serve the purpose. Milk cans too large 

 for immersion in the vessel at hand may be filled with boiling 

 water and should be left filled for five minutes. As a pre- 

 caution against dust contamination, pails and cans, after clean- 

 ing, should be stood bottom side up. Strainers, coolers, etc., 

 should likewise be protected in some manner. In most cases 

 the dirty wire strainers may be replaced by cheesecloth strain- 

 ers. The sources of contamination from water are easily 

 remedied. The location of the source from which contamin- 

 ation is derived may be determined by taking samples of milk 



