Selection of Saccharomyces pastorianus variants with improved fermentation performance under very high gravity wort conditions

Abstract

Saccharomyces pastorianus FBY0095 was mutated and variants were selected for efficient very high gravity brewing using 15% (w/v) maltose and 15% (w/v) ethanol. Two useful variants were obtained of which one (L6) had growth, wort consumption and ethanol production rates of 0.036, 1.13 and 0.49 g l(-1) h(-1), respectively. The corresponding results for the wild type were 0.028, 0.98 and 0.4 g l(-1) h(-1), respectively. The vitality of the variant (expressed as acidification power) was 2.5 while that of the wild type was 2.3. There was also an obvious improvement on flavor of resulting beer when using L6 and the other variant.

Flavor impacts of glycerol in the processing of yeast fermented beverages: a review

“…The reason could be that more DHAP and NADH were generated in high monosaccharide condition. The drawbacks of the high sugar fermentation lies at that it often leads to lower growth rate, longer lag phase, incomplete sugar utilization and strongly accumulations of acetaldehyde and acetate esters ( Jiménez-Martí et al 2011;Piddocke et al 2009;Yu et al 2012). More than two folds increase in ethyl acetate and isoamyl acetate was accumulated and the disproportional changes of flavor-active metabolites have resulted in the over-fruity character of beer (Piddocke et al 2009).…”

“…The higher temperature and higher sugar concentration, which were in favor of glycerol formation, led to over accumulation of acetic acid, acetaldehyde and higher alcohols. Even worse, inadequate optimizations also impaired yeast growth and further affected the fermentation kinetics and the overall flavor balance (Csutorás et al 2014;Du et al 2011;Liu et al 2014;Piddocke et al 2009;Yu et al 2012).…”

Gravity-Driven Adaptive Evolution of an Industrial Brewer’s Yeast Strain towards a Snowflake Phenotype in a 3D-Printed Mini Tower Fermentor

“…A number of investigations have demonstrated the feasibility of directing evolution in natural Saccharomyces pastorianus hybrid stains in order to create variant strains with improved functional properties [6]. Such investigations have focused on adaptation to very high-gravity brewing conditions [7][8][9], associated stresses (such as osmotic stress and ethanol toxicity) [10,11], or the modification of the production of flavour compounds [12]. ALE has also been utilised to enhance the fermentation rate of S. cerevisiae with decreased formation of acetate and greater production of aroma compounds [13,14].…”

Fermentation performance of lager yeast in high gravity beer fermentations with different sugar supplementations

“…4466 was used in this study. This strain was selected from industrial lager strain with improved fermentation performance for high gravity fermentation in our previous study (10).…”