Production of Diacetyl, Pentandion, Acetaldehyd, Etylacetate and Isoamylacetate with Different Yeast Concentration

Abstract

The aim of this work is to study the influence of yeast concentration in fermentation, in all its stages and the influence on forming the higher alcohols as important components of beer. The yeast concentration is important for reaching the desired fermentation parameters and the right concentration of higher alcohols as for the quality of beer in general. The attenuation degree has been raised with the rising of yeast concentration and the samples 4,5 and 6 have the higher degree of fermentation than samples 1,2 and 3 where the yeast concentration is smaller. Chemical analyses of final beer show that the highest degree of fermentation is reached at sample 5, where the apparent degree of fermentation is 84.06%. As for higher alcohols they differ in an independent way from each other and while at propanol and isobutanol we have the light rising of values with the rise of yeast concentration, at isoamyl alcohol occurs the opposite thing and have the small drop of values.

Keywords: beer, fermentation, extract, yeast, concentration, cells, biomass, higher alcohols.