Unlocking the potential of Zygosaccharomyces bailii: A novel non-Saccharomyces yeast in brewing

Abstract

Beer has long been an important part of culture, with the brewing industry combining both traditional methods and modern innovation, which has helped beer?s evolution over time. Today, the increasing prominence of microbreweries and their expanding market influence have led to a growing interest in identifying elements that can distinguish one beer from another. One such factor is the use of non-Saccharomyces yeast strains for fermentation. Among these, Zygosaccharomyces bailii (Z. bailii), typically known as a spoilage microorganism, presents promising potential as an unconventional yeast for brewing. This study aimed to evaluate the fermentation characteristics of Z. bailii and its potential to produce beers with desirable features. To assess its fermentative capacity, Z. bailiiwas tested both as a monoculture and in mixed fermentations with Saccharomyces cerevisiae (S. cerevisiae) at ratios of 1:1, 1:10, and 1:20, across two original gravities (16 °P and 12 °P) at 20 °C. After confirming that Z. bailii could successfully initiate and complete the fermentations, the final beer characteristics were analyzed. The results demonstrated that Z. bailii can produce an alcoholic beverage with unique attributes, including a significant decrease in the pH of the final beer. Furthermore, no issues arose during fermentation at high original gravities, and all fermentations achieved the desired ethanol levels. Notably, a strong phenolic character was detected in the final beers, though it was not considered particularly off-flavor. In conclusion, the use of Z. bailii offers the potential to create a complex and innovative beer profile that may appeal to consumers. While Z. bailii is not yet suitable for large-scale industrial applications, its distinct traits suggest that it could become a valuable yeast strain for future beer production.