Brewing potential of Wickerhamomyces anomalus: Growth, fermentation, and aroma characteristics

• W. anomalus grew tenfold more than US-05, showing a strong growth advantage. • W. anomalus metabolized more sugars and had higher ethanol tolerance than US-05. • Oxygen supply improved W. anomalus fermentation, boosting sugar conversion efficiency. • Beers brewed with W. anomalus had enriched ester and alcohol profiles under oxygenation. This study assesses the brewing potential of Wickerhamomyces anomalus , with emphasis on its growth behavior, fermentation efficiency, and aroma formation under oxygenated versus anaerobic conditions. Wild yeasts isolated from flowers revealed W. anomalus as a dominant species. Under laboratory conditions, W. anomalus exhibited a rapid growth rate, reaching ∼2.6 × 10 8 cell/mL—nearly tenfold higher than Saccharomyces cerevisiae US-05—and utilized a broader range of sugars. However, in static wort fermentation, its viability dropped to 27%, and sugar utilization remained below 20%, indicating strong oxygen dependence. Supplying oxygen (>33 mg/mL) restored fermentation performance, increasing sugar consumption by ∼40% and significantly elevating ester production. GC–MS analysis showed 2.7-fold higher ethyl acetate, 5.5-fold higher isoamyl acetate, and 8-fold higher 2-methylbutyl acetate in oxygenated fermentations (p<0.05). PCA demonstrated clear separation among yeast treatments, with PC1 and PC2 explaining 55.99% and 44.01% of total variance, respectively. Overall, oxygen-supported W. anomalus fermentation produced beers with markedly enhanced fruity and floral ester profiles, highlighting its value as a non- Saccharomyces yeast for creating novel, aroma-forward craft beers. These results underscore its industrial potential while identifying limited anaerobic tolerance as the key barrier to commercial adoption. Future work should explore adaptive evolution, oxygen-controlled brewing designs, and co-fermentation strategies to improve viability under brewing conditions.