Yeasts Isolated From Urban Honeys: Diversity and Potential Application in Mead Production

This study aimed to isolate, identify, and evaluate yeasts originating from urban honeys as potential starters for mead production. Honey samples from urban apiaries from Poland were analyzed. A total of 47 yeast isolates were obtained and identified as belonging to eight genera: Starmerella, Zygosaccharomyces, Saccharomyces, Rhodotorula, Dothiora, Cystobasidium, Schizosaccharomyces, and Filobasidium. Among them, Starmerella magnoliae was predominant (24 isolates). Zygosaccharomyces rouxii and Z. mellis also occurred frequently. Three Saccharomyces cerevisiae strains (CMIFS 189, CMIFS 191, CMIFS 208) were selected for further trials and applied in the fermentation of trójniak-type meads (honey-to-water ratio 1:2), together with a reference mead starter, Enovini® HONEY (Browin, Poland). Physicochemical analysis showed ethanol contents of 12.22%-15.49%, with CMIFS 191 producing the lowest alcohol but the highest extract. Glycerol levels (0.62%-0.85%) were lower than literature values, while volatile acidity ranged from 0.80 to 1.27 g/L and total acidity from 2.97 to 3.45 g/L. Polyphenol levels (270-299 µg/mL) were high, and antioxidant assays (ABTS, DPPH, RP) showed strain-dependent effects. Volatile analysis revealed alcohols as the dominant group, followed by esters and aldehydes, shaping fruity and floral aroma notes. Based on sensory evaluation, CMIFS 191 showed the highest overall acceptability, whereas the Enovini® HONEY reference starter obtained the lowest sensory scores under the applied conditions. Overall, honey-derived S. cerevisiae strains showed strong potential as novel starters for mead production.