Optimizing yeast strain selection for mulberry wine fermentation: a performance-based approach

Abstract

This study focused on identifying the optimal yeast strain for Dechang mulberry wine fermentation blended through a multi-stage evaluation process using five commercial yeasts. Initially, the Durham tube fermentation method and weight-based analysis were employed for initial screening. Subsequently, a secondary evaluation involving physical, chemical, and sensory assessments was conducted. The final stage assessed yeast tolerance to ethanol and sulfur dioxide (SO₂), and the wine’s volatile compounds were analyzed using gas chromatography-mass spectrometry. The L13 yeast strain emerged as superior, demonstrating efficient fermentation initiation, rapid primary fermentation, and production of a desirable wine profile, including optimal sugar, acid, and alcohol levels. Notably, the L13 yeast strain showed resilience, tolerating up to 11% ethanol and 170-mg/L SO₂ within 7 days, and contributed to a rich aromatic profile with 23 volatile compounds, including 13 esters. These attributes render the L13 strain particularly suitable for producing mulberry wine with robust fermentation characteristics and a complex aroma, enhancing both quality and sensory appeal of the final product.