Ecologization of Joint Production of Alcohol and Bakery Yeast From Molasses

Abstract

Background. The disadvantage of the two-product technology of alcohol and baker’s yeast from molasses is the need to limit the concentration of dry matter of the source medium to 22% and, accordingly, the level of alcohol accumulation in mature malt not more than 8.0% vol. to prevent deterioration of baker’s yeast. The consequence of this is the high specific cost of steam for bragorectification and increase the specific yield of post-alcohol molasses bard in comparison with single-product technology (obtaining only alcohol). Materials and methods. Raw materials, intermediates and final products were analyzed according to the methods adopted in science and practice of molasses alcohol technology. The dry matter content; pH of the medium; the content of alcohol in the brew, yeast biomass and unfermented sugars; the lifting power of yeast and their color in the resulting products were determined. Results. The possibility of reducing the volume of post-alcoholic molasses bard by returning it for the preparation of molasses bard without deteriorating the quality of baker’s yeast and alcohol yield, as well as by increasing the dry matter concentration of fermented wort from 22 (traditional technology) to 27% and accumulation of alcohol in mature brew up to 10–11% vol. has been experimentally proven. Conclusion. The presented research results provide grounds for the development of energy-saving low-waste two-stage technology of alcohol and baking yeast from mo­lasses, which can be used to obtain high-quality baking yeast to increase the con­centration of alcohol in mature malt by more than 10% vol. This will significantly reduce the steam for bragorectification of alcohol and the volume of contaminated and difficult to dispose of production waste – post-alcohol molasses bard. The implementation of such technology will be the next step in the greening of the joint production of alcohol and baker’s yeast from molasses.