PRODUCED BY ALCOHOLIC FERMENTS. 229 



Belohoubek was the first to express the opinion that Myco- 

 derma cerevisics can, under certain conditions, cause injury 

 in the brewery. Four years later, in 1889, Kukla published 

 some papers on beer turbidity in the * Berichte der Versuchs- 

 Anstalt fur Brauindustrie in Bb'hmen.' This disease occurred 

 in two ways. After the beer had been three to four weeks in 

 the lager casks, it became charged, so to speak, with a fine 

 dust, which increased from day to day. In the second case 

 the beer was bright after the completion of the fermentation 

 in the lager cellar, and it only became " dusty " after it was 

 drawn off, and had been some time in the consumers' cellars. 

 Both forms of the disease were attributed to Mycoderma cere- 

 visice having been present and multiplied during the primary 

 fermentation. Kukla further expresses the view that the 

 weak wort of 10 per cent. Ball., generally employed in the 

 Bohemian breweries, affords an especially favourable medium 

 for the fungus in question. He also believes that at the time 

 when his experiments were made, the malt was abormal in its 

 composition in respect of the ratio between the different 

 albuminoid matters, and that the proportion of sugars to non- 

 sugars in the wort was an unfavourable one. Kukla does not, 

 however, give any scientific confirmation in support of his 

 views. He promises to do so in a special treatise, and until 

 this appears it is not possible to decide these questions. 



In the treatise in which I, some years ago, studied the 

 behaviour of the yeast fungi with reference to the different 

 sugars, I suggested that the name Mycoderma cerevisicz in- 

 cluded not merely one, but several species. Lasche's 

 investigations were, however, the first to give us definite 

 information on this point. In his ( Mitteilungen aus Wahl 

 und Henius' Versuchsstation fur Brauerei in Chicago,' 1891, 

 he describes how he separated from cloudy beer four different 

 varieties or species, all of which may be included under the 

 old systematic name Mycoderma cerevisics. He conducted 

 experiments with them in flasks charged with wort at 10 C., 



