Bacteria and Butter-Making. 159 



given for their germination, they are almost sure to develop. 

 In some cases the mold is due to the growth of the ordinary 

 bread mold, Penicillium glaucum; in other cases a black 

 mold develops, due often to Cladosporium butyri. Not in- 

 frequently trouble of this character is associated with the 

 use of parchment wrappers. The difficulty can easily be 

 held in check by soaking the parchment linings and the 

 tubs in a strong brine. 



Fishy butter. Considerable trouble has been experienced 

 in Australian butter exported to Europe in which a fishy 

 flavor developed. It was noted that the production of this 

 defect seemed to be dependent upon the storage tempera- 

 ture at which the butter was kept. When the butter was 

 refrigerated at 15 F. no further difficulty was experienced. 

 It is claimed that the cause of this condition is due to the 

 formation of trimethylamine (herring brine odor) due to 

 the growth of the mold fungus Oidium lactis, developing 

 in combination with the lactic-acid bacteria. 



