Influence of the yeast aeration method on the quality characteristics of beer

Abstract

Aeration of wort in brewing, as a traditional way to reduce the need for yeast oxygen, has several disadvantages associated with a change in the quality of the finished beverage. Another approach to solving this problem is the pre-fermentation preparation of brewer’s yeast, which consists in short-term aeration (30 min) of the inoculum followed by exposure without air for 2 hours. The effect of various methods of supplying the yeast culture with atmospheric oxygen on the formation of flavoring substances and change in physicochemical characteristics of beer. Objects of research are bottom fermentation yeast Saccharomyces cerevisiae, young and finished beer. It was revealed that in young beer fermented with yeast after aeration, the content of sensory significant components (higher alcohols, acetaldehyde, diacetyl) is on average 27% lower than in the variant with wort aeration. A possible reason for this is the high activity in the prepared inoculum in comparison with the initial culture of enzymes (1.7-1.8 times increased) involved in the conversion of by-products. Stimulation of the metabolic processes of yeast with oxygen, especially in the sample with aeration of the wort, creates the conditions for reducing (from 7 to 23%) the main mutating components. However, pre-aeration of the inoculum allows you to get a ready drink with the best taste and aromatic characteristics, which is the advantage of this method in comparison with aeration of the wort.