Selection of Indigenous Yeast Strains for Low-Methanol Production and Quality Improvement in Kiwifruit Wine

Commercial Saccharomyces cerevisiae strains often fail to capture the varietal typicity of kiwifruit wine, a shortfall that compromises flavor and raises methanol-related safety concerns. This study therefore screened indigenous yeasts to enhance sensory profiles and fermentation safety. Five indigenous strains were benchmarked against the commercial standard EC1118. All five strains tolerated high ethanol concentrations and produced significantly higher ethanol levels than EC1118 (p < 0.05). Critically, the final methanol concentration in F4-fermented wine was significantly lower than that in EC1118 wine, dropping by 30.65 mg/L, a decrease of 10.74%, and the content of higher alcohols was also lower. Gas chromatography–mass spectrometry (GC-MS) and odor activity value (OAV) analyses showed that F4 increased the levels and OAVs of fruity esters and floral aroma-active compounds. In the comprehensive evaluation, strain F4 fermented robustly and produced kiwifruit wine with a favorable flavor profile. Consequently, F4 fermented robustly and yielded kiwifruit wine with lower final concentrations of methanol and higher alcohols, together with higher OAVs of fruity esters and floral aroma-active compounds, making it a promising candidate for kiwifruit wine production.