Comparison of assimilation of fermentable sugars in wort by the immobilized yeast in alginate gel and the free yeast in high gravity brewing

Abstract

In this work, the assimilation of different fermentable sugars by the immobilized yeast in alginate gel and the free yeast under high gravity brewing conditions was investigated and compared. Both immobilized and free yeast utilized glucose, fructose, sucrose and maltose in wort from the beginning of the fermentation. Maltotriose uptake of the fixed cells was also observed during the first hours of fermentation while the free cells only started assimilating maltotriose after the first 48 h. High osmotic pressure at the start of the fermentation changed cellular morphology and that could decelerate the maltotriose uptake of the free yeast.