Screening Non-Saccharomyces Yeasts as Low Ethanol Producing Starter Cultures

Abstract

Non-Saccharomyces yeasts are known for their low fermentation rate in comparison to Saccharomycescerevisiae. In this study, non-Saccharomyces yeasts were inoculated into Chenin blanc grape must andfermented under aerobic and anaerobic conditions. Saccharomycodes ludwigii displayed a straindependentfermentation rate, which yielded between 5.2% and 9.9% ethanol concentration under bothconditions, albeit with residual sugar. Aerobic conditions favoured the production of reduced ethanolwhich was between 5.8% and 9.7% for non-Saccharomyces yeasts in comparison to S. cerevisiae (10%).This trend was observed for Wickerhamomyces anomalus, Stamerella bacillaris (Candida zemplinina),Metshnikowia pulcherrima, Cyberlindnera saturnus, Wickerhamomyces subpelliculosus and Cyberlindnerajadinii. The laboratory-scale wines prepared with the aforementioned yeasts yielded ripe fruit and floralaroma attributes while other non-Saccharomyces yeasts resulted in wines with spicy, acidic and solventaroma notes.