Development of a New Assay for Measuring H2S Production during Alcoholic Fermentation: Application to the Evaluation of the Main Factors Impacting H2S Production by Three Saccharomyces cerevisiae Wine Strains

Hydrogen sulfide (H2S) is the main volatile sulfur compound produced by Saccharomyces cerevisiae during alcoholic fermentation and its overproduction leads to poor wine sensory profiles. Several factors modulate H2S production and winemakers and researchers require an easy quantitative tool to quantify their impact. In this work, we developed a new sensitive method for the evaluation of total H2S production during alcoholic fermentation using a metal trap and a fluorescent probe. With this method, we evaluated the combined impact of three major factors influencing sulfide production by wine yeast during alcoholic fermentation: assimilable nitrogen, sulfur dioxide and strain, using a full factorial experimental design. All three factors significantly impacted H2S production, with variations according to strains. This method enables large experimental designs for the better understanding of sulfide production by yeasts during fermentation.