SARCINA TURBIDITY IN BEER 287 



detected in wort cultures. The unrestricted access of air is essen- 

 tially necessary to the growth and activity of this bacillus. The 

 organism is incapable of injuring beer except when present in 

 large numbers in the wort before the commencement of primary 

 fermentation. 



The number of organisms capable of rendering wort viscid is 

 not exhausted by the Schizomycetes already mentioned. In the 

 second volume we shall become acquainted with Dematium pullu- 

 lans, a species of Eumycetes which is equally. capable of producing 

 damage of this kind. 



167. The so-called Sareina Turbidity in Beer 



will now be referred to, although no mucinous ferments are here 

 in question. Bottom-fermentation beer is required to be perfectly 

 clear, and if it proves defective in this particular, it is considered 

 poor or bad, according to the nature of the turbidity. This may 

 arise from several distinct causes : precipitated albuminoids = 

 gluten turbidity ; the presence of unsaccharified starch = starch 

 turbidity ; precipitated hop resins = hop dimness ; a high content 

 of yeast-cells = yeast turbidity ; or, finally, strong infection with 

 fission fungi = bacterial turbidity. This latter, again, may be 

 caused by different species of organisms, a few of which (i.e. those 

 producing turned and ropy beer) have already been mentioned, the 

 turbidity in their case being merely a secondary phenomenon 

 attendant on another complaint. In the following lines, however, 

 we will confine ourselves to the turbidity caused by bacteria of the 

 sarcina or pediococcus form of growth. Very frequently these 

 organisms (in enormous numbers) are the only ones observable in 

 samples of turbid beer. 



The first observations on the subject were made by PASTEUR and 

 J. BERSCH (II.), and more minute researches were made by Julius 

 Balcke, from whom these organisms first received the name of 

 Sarcina. Francke afterwards found that this fission fungus always 

 subdivides in two directions only (and not three), and consequently 

 forms sheet colonies. On this account FRANCKE (I.) in 1884 

 applied the new generic name of Pediococcus cerevisice to this 

 microbe. Notwithstanding this, it is still customary to term the 

 malady under consideration "sarcina turbidity;" which is, more- 

 over, partly correct, since true sarcina in great numbers have also 

 been found in turbid beers. The first successful attempt to obtain 

 a pure culture of such a pediococcus was made by P. LINDNER (II.) 

 in 1888. The Pediococcus cerevisice isolated by him from "sarcina 

 turbid" beer occurs as single cocci (0.9-1.5 /x diameter), diplococci, 

 and tetrads. Still, though it is undoubtedly the fact that this 

 fission fungus occurs in large numbers in such turbid beers, it by 

 no means follows that the organism can be positively assumed to 

 be the cause of sarcina turbidity, attempts to grow it in sterilised 



