Beyond standard brewing yeasts: exploring fermentative and aroma diversity in beers produced with commercial non-conventional strains

Non-conventional yeasts are increasingly shifting from being regarded as spoilage microorganisms to becoming valuable tools for brewing innovation, particularly for the development of low- and no-alcohol (NoLo) beers and for expanding sensory diversity. However, systematic comparative information on the fermentative and aroma-related performance of commercially available yeasts across taxonomic groups remains limited. Here, we performed a comprehensive comparative assessment of a wide selection of commercial non-conventional yeasts belonging to multiple genera, evaluated under standardized brewing conditions and benchmarked against two reference brewing strains. Fermentation performance, substrate utilization, ethanol production, and volatile aroma profiles were systematically analyzed and integrated with sensory evaluation. The results revealed pronounced strain- and genus-dependent differences in fermentation efficiency and aroma compound production, highlighting the substantial diversity currently available within the commercial non-conventional yeasts market. Lachancea spp. exhibited the highest fermentative capacity alongside notable acidification and glycerol production, with marked strain-dependent variability. Torulaspora delbrueckii showed consistently low attenuation and limited maltose utilization. Saccharomycodes ludwigii and S. cerevisiae var. chevalieri produced low ethanol levels, confirming their suitability for NoLo brewing, while differing markedly in phenolic and ester profiles. Hanseniaspora uvarum and Cyberlindnera saturnus stood out for their pronounced fruity ester production, with exceptionally high acetate ester formation in the latter. By providing an integrated overview of fermentative and sensory-relevant traits across a broad taxonomic spectrum, this work advances understanding of non-conventional yeasts in brewing innovation, particularly within the rapidly growing global low- and no-alcohol beer sector, and offers a comparative framework relevant to brewers and researchers worldwide.