Kew York Agricultural Exterlmext Station. o'J 



method of detection. 



The following di 7 samples from each patron's milk were 

 taken in scalded milk jars by the maker, cooled, numbered and 

 delivered at the Station in the afternoon. The samples were 

 then heated to 70° F., rennet added and the milk held at 70° F. 

 until morning. At the end of 18 hours all the samp.es were 

 curdled normally except two. These showed much whey on top, 

 considerable gas in the curd and had a bad smell. On draining 

 the curd one of these developed a markedly bitter flavor. Ou 

 reporting these facts to the maker it was found that this was 

 from the very patron whose milk had been selected for making 

 the original bitter cheese. The maker was advised to scald once 

 more all the cans and cloths that had been used, and proceed 

 with milk from a different source.- He later reported that on 

 following this suggestion the trouble disappeared. 



DUE TO THE ACTIVITY OF BACTERIA. 



Since the bitter flavor did not exist in the fresh milk, but only 

 appeared a day or two later in the curd and for some time con- 

 tinued to increase in quantity it was evidently connected with 

 some form of life. 



Cultures made from the bitter cheese and from the samples of 

 milk furnished a variety of forms of bacteria and molds, and 

 these were tested by preparing a pure-culture starter of each, 

 adding it to some fresh milk from our own dairy and making 

 small Neufchatel cheeses. To make sure that any bad flavors 

 found in these experimental cheeses were not due to anything 

 contained in our own dairy several samples of the same milk 

 were made into cheese without the addition of any starter. 



These control cheeses and nearly all of the cheeses to which 

 pure cultures of different kinds had been added, were free from 

 any bitter flavor, but one form was found that quite uniformly, 

 gave bitter cheese under these conditions. This germ was a 

 short bacillus, forming sufficient acid when grown in sterile milk 

 to produce curdling in one or two days. 



