Microscope in the brewery and malt-house / by Chas. Geo. Matthews and Francis Edw. Lott.

  • Matthews, Chas. Geo. (Charles George)
Date:
1889
Catalogue details

Licence: Public Domain Mark

Credit: Microscope in the brewery and malt-house / by Chas. Geo. Matthews and Francis Edw. Lott. Source: Wellcome Collection.

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    Beer-wort. The cloudiness in the ales spoken of lasted a very long time, accompanied by marked flatness. Mycoderma Vini. Most Brewers are familiar with the white greasy film that this organism develops on Beer that is spilt about, or left exposed to the air in shallow vessels, as also with its appearance round the taps and shives of casks. In this capacity it is acting as an aerobian ferment, absorbing oxygen, and simultaneously destroying the alcohol of the beer, forming from it Carbonic acid gas and water. Its growth under these conditions is very rapid : Engel implies that in 48 hours, one cell may produce 35,000. Plate V-, Fig. 6, left half disc, shows the aerobian form. Its dimen- sions are very variable, depending greatly on the conditions attending growth. If these are unfavourable the cells may be as small as S. Ellipsoideus, whilst on the other hand in a very free growth they may be quite twice as large. The average length of those depicted is about 9 fx. Pasteur showed, in addition to other points connected with Saccharomyces Mycoderma or Mycoderma Vini, that when submerged in a fermentable liquid it acts as a slow ferment, forming alcohol and Carbonic acid gas, the cells meanwhile undergoing some alteration in appearance, [Plate V., Fig. 6, right half disc] the filled out brighter cells being the active form. Where ales are badly bottled, and left standing upright with leaky corks, a film of Mycoderma Vini not unfrequently forms on the surface, and may do this to a limited extent where the corks are fairly sound. This film on being submerged can, if the leakage stops, act as an alcoholic ferment. If the leakage goes on, the Mycoderma Vini falls in flakes through the liquid, which becomes utterly spoilt. Ordinary well-bottled ales not unfrequently show some
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