On fermentation / by P. Schützenberger.

  • Schützenberger, P. (Paul), 1829-1897.
Date:
1883
Catalogue details

Licence: Public Domain Mark

Credit: On fermentation / by P. Schützenberger. Source: Wellcome Collection.

    165/388 (page 153)
    (•99 Ibs. avoir.) of dried yeast per hectolitre (22 gallons) of beer ; allowing that tins beer contains 8 per cent, of alcohol, fermentation would hâve acted on 15-5 kilo- grammes of sugar, there would then be 2‘9 grammes of new yeast for 100 of decomposed sugar ; these numbers do not differ so much as the first, from the results obtained on a small scale ; it is true, however, that in this calculation, we hâve taken for the proportion of alcohol a vcry high weight which ought, perhaps, to be reduced. The apparent contradiction bctween the results of the laboratory experiments and those of commercial opera- tions, may be explained by admitting, that the develop- ment and multiplication of the cells of yeast are not so much dépendent on the quantity of sugar decomposed, as the laboratory experiments seem to indicate, that they may vary within vcry wide limits, according to the composition of the medium in which the operation takes place. This explanation seems to be corroborated by the following experiments of Mayer (Landwi, Versuchsz, vol. 16, p. 304). The author fermented two portions of the boiled must of grapes of the capacity of 190 cubic centimètres (11-59 cub. in). To one, he added imperceptible traces of wine-lees {Saccharomyces ellips), and sowed in the other a little beer-yeast. When the sugar had disappeared, which required several weeks, he found— I. 2. Saccharomyces ellip. » cerevisiœ ALCOHOL CORRESPONDING YEAST FORMED. SUGAR DECOMPOSED. FORMED. gr- gr- gr- 13-11 25-6 2-38 15 2 297 2-04