Investigation into the Potential of Lachancea fermentati Strain KBI 12.1 for Low Alcohol Beer Brewing

Abstract

In brewing research, non-Saccharomyces yeasts have gained attention in recent years, owing to their potential to influence the characteristics and flavor of beer. The Lachancea genus possesses an uncommon trait, the production of significant amounts of lactic acid during alcoholic fermentation. This trait could potentially be harnessed for brewing purposes, particularly for the production of low alcohol beer. In this study, the potential of Lachancea fermentati strain KBI 12.1 was investigated for the production of low alcohol beer in low gravity wort. KBI 12.1 was characterized for sugar utilization, hop sensitivity, phenolic off-flavor (POF) production, and propagation performance. Lab scale fermentation trials in diluted wort (6.6°P) were conducted and compared to a brewers’ yeast, Saccharomyces cerevisiae WLP001. Fermentations were monitored for lactic acid and ethanol production, pH drop, and sugar consumption. In the final beers, amino acid and free amino nitrogen (FAN) content were determined and secondary metabolites were quantified. Lachancea fermentati KBI 12.1 showed to be unable to utilize maltotriose. The strain exhibited no POF production, minor hop sensitivity, and excellent propagation performance. Amino acid and FAN consumption were much lower compared to that of the brewers’ yeast. In the final beer fermented with KBI 12.1, the lactic acid concentration reached 1.3 g/L, giving the beer a sour taste. During sensory analysis, the beer was additionally described to have a fruity character. In conclusion, Lachancea fermentati KBI 12.1 proved to be a suitable strain for brewing purposes, with promising traits with regard to nonalcoholic and low alcohol beer brewing.