THE SO-CALLED SARCINA TURBIDITY IN BEER 221 



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 pullulans, a species of Eumycetes which is equally 

 capable of producing damage of this kind. 



167. The So-called Sarcina 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 con- 

 fine 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. Not- 

 withstanding this, it is still customary to term the malady under consideration 

 " sarcina turbidity " ; which is, moreover, 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 p. 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 beer having proved unsuccessful. Moreover, as ANTON PETERSEN (I.), 

 E. CHR. HANSEN (V.), and ALFRED JORGENSEN (I.) have shown, a considerable 

 quantity of sarcina may be present in beer without any damage to the beverage 

 (turbidity or unpleasant flavour) resulting therefrom. 



Further particulars given by them render it highly probable, however, that 

 " sarcina turbidity " is actually caused by fission fungi of the pediococcus and 

 sarcina groups, but that the mere presence of these organisms is not sufficient to 

 produce the malady, a special concurrent tendency thereto on the part of the 

 beer being essential. For the determination of the conditions under which the 

 ''sarcina organisms" are capable of producing "sarcina sickness" in beer, we 

 are indebted to an instructive treatise by A. REICHARD (I.). He showed that 

 this turbidity occurs only when the secondary fermentation of the beer goes on 

 with vigour, and that, conversely, a similar degree of sarcina infection is 

 innocuous if the primary fermentation has been carried so far that only a weak 

 secondary fermentation ensue?. Reichard attributes this behaviour (confirmed 

 by searching experiments) to the avidity for oxygen (air-hunger) displayed by 

 the pediococci. It is only when the microbes are continually brought up to the 

 surface of the liquid by the bubbles of carbon dioxide given off during a brisk 



