Technical mycology : the utilization of micro-organisms in the arts and manufactures a practical handbook on fermentation and fermentative processes, for the use of brewers and distillers, analysts, technical and agricultural chemists, pharmacists, and all interested in the industries dependent on fermentation / by Franz Lafar ; translated by Charles T.C. Salter.

  • Lafar, Franz, 1865-1938.
Date:
1910-1911
Catalogue details

Licence: In copyright

Credit: Technical mycology : the utilization of micro-organisms in the arts and manufactures a practical handbook on fermentation and fermentative processes, for the use of brewers and distillers, analysts, technical and agricultural chemists, pharmacists, and all interested in the industries dependent on fermentation / by Franz Lafar ; translated by Charles T.C. Salter. Source: Wellcome Collection.

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    pel led to use very soft brewing liquor (i.e. deficient in lime), and it is a common practice to counteract this evil by adding a little powdered (unburned !) gypsum to the mashing liquor (about i^oz. per 1000 galls.). Very satisfactory results are obtained : good head, thorough fermentation, good “ break ” and a firm sedimental yeast (provided the yeast employed is capable of furnishing such, see vol. i. p. 256). We are indebted to H. Seyffert (I.) for an in- teresting example, relating to a St. Petersburg brewery, working with a liquor containing only 1.3 parts of CaO per 100,000. After having failed to obtain satisfactory fermentation with a series of pure yeasts, of German origin, it was finally decided to examine the worts, and these were found to be deficient in lime, so that the yeasts grown in them became more and more impoverished in that constituent, as can be seen from the table (vol. ii. p. 196). (The column headed CuO will be dealt with later on.) The yeasts were famished in respect of lime, and even absorbed the small quantities of that base present in the water with which they were washed (vol. ii. p. 118). H. Seyffert pushed his experiments to the furthest limit, by reducing the already small lime content of the wort still more by dialysis, before pitching it with yeast. In these circumstances a highly frothy fermentation (vol. ii. p. 184) ensued. His observa- tions have also a certain value in connection with the pure culture of yeast, since they demonstrate that a successful result depends not only on the happy selection of a suitable race of yeast, but also on the favourable composition of the nutrient medium— a point already insisted on by Hansen (III.). Hence, in cases where the application of pure yeast does not fulfil expectations, one should not immediately condemn the innovation. The yeast can only furnish good results when a suitable medium is provided —and this is the task of the practical man. § 259.—The Phosphoric Acid Requirements of Yeast. Yeast requires a good deal of phosphoric acid ; and, as can be seen from particulars already given, a considerable amount of this acid is present in the ash. The figures given in the table on p. 193 agree with those reported by K. Lintner (IV.) as obtained at the Munich Experimental Station, and ranging between the limits of 3.21 and 3.84 percent, of P205 (referred to dry matter), the mean being 3.61 per cent. All these values, however, are surpassed by 59.5 per cent, of P,0. found in the ash of English top-fermenta- tion yeast by A. 0. Salmon and W. de Verb Mathew (I.). Under ordinary conditions in the brewery the needs of the yeasts for phosphoric acid are satisfied by the phosphates and organic phosphorus compounds present in the malt, though in some cases the amount contained in the barley and malt is in- adequate. As a rule, 0.9 per cent., calculated on the dry residue,