172 Dairy Bacteriology. 



terially affects the production of gas. At high curing 

 temperatures, the gas-producing bacteria are able to de- 

 velop more rapidly; therefore, more trouble is experienced 

 in summer than at other seasons. The relation of tem- 

 perature of curing-room to the ripening of cheese is a 

 question of very great importance. We may, roughly 

 speaking, divide normal temperatures into three zones 

 more or less well marked, safe, hazardous, and danger- 

 ous. Where the temperature exceeds 70 F., the ripen- 

 ing of the cheese is apt to be impaired. At these high 

 temperatures, gas- generating forms are apt to become 

 prominent. 



179. Detection of tainted milks. Taints in milk 

 may be due to two sets of causes. They may be pro- 

 duced by bacterial agency or absorbed directly from some 

 pre-existing source. Those belonging to the first class 

 are extremely difficult to detect at the weigh-can, for the 

 taint itself may not be pronounced, while the organism 

 causing it may exist in the milk in large numbers. 

 Taints of this class are especially dangerous, for they are 

 produced by vital causes which may further develop, and 

 thereby greatly intensify the undesirable condition. 

 Taints due to absorption can, if prominent, be recognized 

 by sense of smell. A detection of these is facilitated by 

 warming the milk, thus permitting the contained odors 

 to escape more readily. 



It is extremely desirable that some method of recog- 

 nizing these taints of microbic origin should be employed, 

 but thus far, no rapid way has been devised that is ap- 

 plicable at the weigh-can. It is possible, however, to 

 treat the milk by making what is known as a fermenta- 

 tion test, and thus encourage the early development of the 

 contained bacteria, but these methods are only of use in 

 preventing future troubles. 



