152 Dairy Bacteriology. 



a serious cheese defect that occurs frequently in Scotland, 

 viz., the discoloration of cheese. 



The use of stringy or slimy whey has been advocated in 

 Holland for some years as a means of overcoming the 

 tendency toward gas formation in Edam cheese which is 

 made from practically sweet milk . This fermentation , the 

 essential feature of which is produced by a culture of 

 Streptococcus Hollandicus 1 , develops acid in a marked 

 degree, thereby inhibiting the production of gas. 



159. Bacteria in rennet. The addition of rennet to 

 milk has no appreciable effect on the development of the 

 bacteria in the same. The idea has been advanced that 

 the bacteria in the rennet extract exert a considerable 

 influence on the cheese; this view is, however, hardly 

 tenable, in spite of the fact that the rennet usually con- 

 tains large numbers of organisms, for the relative amount 

 of rennet that is added is so small that this does not per- 

 ceptibly increase the germ content of the milk. 



It is possible that undesirable bacteria may be intro- 

 duced into the milk by means of the rennet where the 

 same is contaminated with noxious forms ; but these cases 

 are relatively rare . This might apply particularly to those 

 cases in which the natural rennets are used. These are 

 preserved in salt, alcohol, or boric acid, but they are 

 never free from bacteria. Adametz 2 found ten different 

 species and from 640,000-900,000 bacteria per cc. in 

 rennets. 



160. Green cheese. If the proper amount of acid 

 has been allowed to develop, a cheese fresh from the 

 press will present a close uniform texture, that in the 

 "green" condition is tough and elastic. This rapidly 

 changes as the cheese ripens, and with this change there 

 is a marked increase in the amount of bacterial life. 



1 Weigmann, Milch Ztg., No. 50. 1889. 



2 Adametz, Landw. Jahr., 18: 256. 



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