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A STUDY OF THE MICROFLORA OF TWO TURBID BEERS
Author(s) -
Cosbie A. J. Curtin,
Tošić J.,
Walker T. K.
Publication year - 1941
Publication title -
journal of the institute of brewing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.523
H-Index - 51
eISSN - 2050-0416
pISSN - 0046-9750
DOI - 10.1002/j.2050-0416.1941.tb06128.x
Subject(s) - acetobacter , turbidity , yeast , wine , food science , virulence , haze , biology , chemistry , microbiology and biotechnology , ecology , biochemistry , fermentation , organic chemistry , gene
This communication describes a study of the microflora of two beers which were very turbid and had developed pronounced acidity. One and the same species of Acetobacter was found to be present in both beers. A single species of Mycoderma also proved to be an infection common to both, and this likewise was separated in pure culture. The Acetobacter was found to produce strong acidity and dense permanent turbidity when inoculated into beer to which air had access. Under the same conditions the Mycoderma developed a pellicle and caused slight increase of acidity and a temporary haziness throughout the beer. In addition to these two organisms a yeast was obtained from one of the beers. Its cultural characteristics proved to be very similar to those of S. cerevisiae, though in one or two respects it differed somewhat from typical brewery yeast. It possessed strong attenuating power and did not cause turbidity. The Acetobacter is to be considered as a virulent beer disease organism. Although similar in some respects to A. capsulatum (Shimwell) in other ways it differs markedly from it, and it also shows important differences from A. viscosum (Baker, Day and Hulton). The new Acetobacter must therefore be regarded as a species different from either of the two last‐named organisms. The Mycoderma species showed characteristics and behaviour similar to those of Mycoderma cerevisiae.