TY - JOUR
T1 - Physiological characterization of brewer's yeast in high-gravity beer fermentations with glucose or maltose syrups as adjuncts
AU - Piddocke, Maya Petrova
AU - kreisz, Stefan
AU - Heldt-Hansen, Hans Peter
AU - Nielsen, Kristian Fog
AU - Olsson, Lisbeth
PY - 2009
Y1 - 2009
N2 - High-gravity brewing, which can decrease production costs by increasing brewery yields, has become an attractive alternative to traditional brewing methods. However, as higher sugar concentration is required, the yeast is exposed to various stresses during fermentation. We evaluated the influence of high-gravity brewing on the fermentation performance of the brewer’s yeast under model brewing conditions. The lager brewer’s strain Weihenstephan 34/70 strain was characterized at three different gravities by adding either glucose or maltose syrups to the basic wort. We observed that increased gravity resulted in a lower specific growth rate, a longer lag phase before initiation of ethanol production, incomplete sugar utilization, and an increase in the concentrations of ethyl acetate and isoamyl acetate in the final beer. Increasing the gravity by adding maltose syrup as opposed to glucose syrup resulted in more balanced fermentation performance in terms of higher cell numbers, respectively, higher wort fermentability and a more favorable flavor profile of the final beer. Our study underlines the effects of the various stress factors on brewer’s yeast metabolism and the influence of the type of sugar syrups on the fermentation performance and the flavor profile of the final beer.
AB - High-gravity brewing, which can decrease production costs by increasing brewery yields, has become an attractive alternative to traditional brewing methods. However, as higher sugar concentration is required, the yeast is exposed to various stresses during fermentation. We evaluated the influence of high-gravity brewing on the fermentation performance of the brewer’s yeast under model brewing conditions. The lager brewer’s strain Weihenstephan 34/70 strain was characterized at three different gravities by adding either glucose or maltose syrups to the basic wort. We observed that increased gravity resulted in a lower specific growth rate, a longer lag phase before initiation of ethanol production, incomplete sugar utilization, and an increase in the concentrations of ethyl acetate and isoamyl acetate in the final beer. Increasing the gravity by adding maltose syrup as opposed to glucose syrup resulted in more balanced fermentation performance in terms of higher cell numbers, respectively, higher wort fermentability and a more favorable flavor profile of the final beer. Our study underlines the effects of the various stress factors on brewer’s yeast metabolism and the influence of the type of sugar syrups on the fermentation performance and the flavor profile of the final beer.
U2 - 10.1007/s00253-009-1930-y
DO - 10.1007/s00253-009-1930-y
M3 - Journal article
C2 - 19343343
SN - 0175-7598
VL - 84
SP - 453
EP - 464
JO - Applied Microbiology and Biotechnology
JF - Applied Microbiology and Biotechnology
IS - 3
ER -