58 Dairy Bacteriology. 



tween taints caused by the growth of bacteria and those 

 attributable to direct absorption. 



If the taint is evident at time of milking, it is in all 

 probability due to character of feed consumed, or possibly 

 to medicines. If, however, the intensity of the taint grows 

 more pronounced as the milk becomes older, then it is 

 probably due to living organisms, which require a certain 

 period of incubation before their fermentative properties 

 are most evident. 



Moreover, if the difficulty is of bacterial origin, it can be 

 frequently transferred to another lot of milk (heated or 

 sterilized is preferable) by inoculating same with some of 

 the original milk. Not all abnormal fermentations are 

 able though to compete with the lactic acid bacteria, and 

 hence outbreaks of this sort soon die out by the re-estab- 

 lishment of more normal conditions. 



Treatment of directly absorbed taints. Much can be 

 done to overcome taints of this nature by exercising greater 

 care in regard to the feed of animals, and especially as to 

 the time of feeding and milking. But with milk already 

 tainted, it is often possible to materially improve its con- 

 dition. Thorough aeration has been frequently recom- 

 mended, but most satisfactory results have been obtained 

 where a combined process of aeration and pasteurization 

 was resorted to. Where the milk is used in making but- 

 ter,, the difficulty has been successfully met by washing the 

 cream with twice its volume of hot water in which a little 

 saltpeter has been dissolved (one teaspoonful per gallon), 

 and then separating it again. 1 



The treatment of abnormal conditions due to bacteria 

 has been given already under the respective sources of in- 



i Alvord, Circ. No. 9, U. S. Dept. Agric. (Div. of Sot.). 



