Synergistic Effect Enhances Aromatic Profile in Beer Brewing Through Mixed-Culture Fermentation of Pichia kluyveri and Saccharomyces cerevisiae var. diastaticus

Saccharomyces cerevisiae is one of the important species of traditional fermented foods and beverages. However, incorporating non-Saccharomyces in the fermentation process is a promising strategy to improve the organoleptic profile. In this study, we assessed the potential of a wild Pichia kluyveri strain (PKL) to augment the aromatic profile in beer brewing while maintaining high fermentation attenuation through inoculation with Saccharomyces cerevisiae var. diastaticus yeast (SY) in both simultaneous (SI-PKL/SY) and sequential (SE-3-PKL/SY) approaches. The fermentation performance was analyzed by residual sugar content, volatile organic compounds, and sensory evaluation. The results indicated that both co-fermentation methods yielded residual sugar levels comparable to those of SY monoculture fermentation. The 2-phenethyl acetate, isoamyl acetate, and linalool in SE-3-PKL/SY increased 12.00, 12.37, and 1.17 folds than the SY monoculture, respectively. Furthermore, the incremental concentrations of these compounds contributed to the highest acceptability and prominent fruity notes in the SE-3-PKL/SY coculture. The current study is the first to report on the co-fermentation with Pichia kluyveri and Saccharomyces cerevisiae var. diastaticus in beer brewing. These findings highlighted the importance of Pichia kluyveri in shaping the ameliorative aroma profile of fermentation production.