BACTERIA. 93 



It is supposed that Sarcina organisms, under certain con- 

 ditions, are capable of producing turbidity in low-fermentation 

 beer. F. SCHOENFELD inoculated a growth of a species which 

 had been cultivated first in yeast-water gelatine and then on 

 yeast-water gelatine under yeast-water, in beer pasteurised 

 at 70 C. After some time the beer became turbid and 

 acquired a sourish-sweet, disagreeable smell and taste. The 

 turbidity set in most quickly when the beer was almost ex- 

 cluded from contact with the atmosphere. 



The slime-forming species described by LINDNER has been 

 mentioned above. 



A. PETERSEN observed that an abundant development of 

 a Sarcina could take place in bottom-fermentation lager- 

 beer without causing any disease ; on the contrary, the 

 beer was bright and stable, and had an agreeable taste and 

 odour. 



Thus, Sarcina species exist which are not productive of any 

 irregularity in the brewery. The same observation has been 

 made by the author. Series of lager-beer samples have fre- 

 quently been examined in the author's laboratory, all of which 

 had the " Sarcina smell and taste," but in which, save in a few 

 isolated cases, there was no development of Sarcina-like 

 organisms. 



A. KEICHARD isolated from low-fermentation beer a Sarcina 

 form which developed freely in unhopped wort, but not in 

 pasteurised beer. This species developed best when the 

 access of the air was limited. In fermentation experiments 

 turbidity or peculiar changes of taste occurred in certain 

 cases, but not in the majority. After many experiments he 

 arrived at the conclusion that these contrary results were due 

 partly to the condition of the various growths of this Sarcina 

 form, partly also to the manner in which the fermentation took 

 place. In cases of quiet fermentation in a larger cask the 

 growth kept at the bottom, and the bacteria did not exert any 

 appreciable influence on the liquid, whereas in the case of a 

 vigorous secondary fermentation they were carried upwards in 

 the liquid along with the carbon dioxide bubbles, after which 

 the disease manifested itself. An addition of beer from the 

 primary fermentation might therefore be injurious in such 



