Recovering, improving and reusing of Yeast in a dried form during fermentation process.

Abstract

Yeast ferment malt sugars, creating carbon dioxide and alcohol as by-products and they are the main drivers of quality beer making. During fermentation, yeast produce a whole range of flavoring compounds, including esters, phenols, and a large variety of other chemicals. These compounds will dramatically change the character of the final beer. However ethanol concentration limits yeast growth during fermentation not all yeast cells die in the process some becomes tolerant to ethanol concentration and live in stressful conditions. Therefore in this project it was evidenced that some yeast cells still live even after fermentation has reached the final stage. 1.02×10^8 viable yeast cells were recovered, improved by successive culturing in medium with fresh foods (nutrients) see page18 from which it increased the strength and fermentation efficiency It was then dried under optimum room temperatures with a nutrient binder (milk starch) to keep with nutrients all the time period and it was reused in the fermentation process as a dry yeast. In the fermentation experiments done it was shown that for in fermentation experiment with yeast immediately after recovery produced 3.2V/V (experiment A),8.1V/V with improved liquid yeast (experiment B) and 8.6 V/V with improved dried yeast (experiment C).Under properly monitored conditions dried yeast has a high fermentation efficiency and produces a great beer than liquid yeast.