Bacteria in Cheese. 189 



Mottled Cheese. The color of cheese is sometimes cut to 

 that extent that the cheese presents a wavy or mottled ap- 

 pearance. This condition is apt to appear if the ripening 

 temperature is somewhat high, or larger quantities of ren- 

 net used than usual. The cause of the defect is obscure, 

 but it has been demonstrated that the same is communi- 

 cable if a starter is made by grating some of this mottled 

 cheese into milk. The bacteriology of the trouble has not 

 yet been worked out, but the defect is undoubtedly due to 

 an organism that is able to grow in the ripening cheese. 

 It has been claimed that the use of a pure lactic ferment 

 as a starter enables one to overcome this defect. 



Bitter Cheese. Bitter flavors are sometimes developed in 

 cheese especially where the ripening process has not been 

 fully completed, or where improper temperatures have been 

 maintained for a considerable length of time. Several or- 

 ganisms associated with this abnormal fermentation have 

 been noted. 



Guillebeau 1 isolated several forms from Emmenthaler 

 cheese which he connected with udder inflammation that 

 were able to produce a bitter substance in cheese. 



Von Freudenreich 2 has described a new form Micrococ- 

 cus easel amari (micrococcus of bitter cheese) that was 

 found in a sample of bitter cheese. This germ is closely 

 related to Conn's micrococcus of bitter milk. It develops 

 lactic acid rapidly, coagulating the milk and producing an 

 intensely bitter taste in the course of one to three days. 

 When milk infected with this organism is made into 

 cheese, there is formed in a few days a decomposition prod- 

 uct that imparts a marked bitter flavor to the cheese. 



1 Guillebeau, Landw. Jahr., 1890, p. 27. 



2 Freudenreich, Fuehl. Landw. Ztg., 43:361. 



