About Hydrogen Sulfide

Hydrogen sulfide (H2S) is a well-known contaminant found in some concentration in every wine, beer or other yeast-fermented beverage. H2S contamination occurs naturally as a byproduct of conventional yeast fermentation. A significant percentage of all wine fermentations may be so heavily tainted with this contaminant that a noxious odor – reminiscent of “rotten eggs” – is unmistakable, necessitating remediation. 

The costs associated with remediation of wines contaminated with high concentrations of H2S, (achieved through labor-intensive measures such as aeration or the introduction of copper sulphate) can, in some instances, include significant impacts on the wine’s quality and pricing while also requiring the winemaker’s extra involvement and attention to the process.

Rather than wasting valuable resources on unnecessary remediation, progressive winemakers are taking the preventive (and much more cost-effective) approach of using our H2S-preventing yeasts to eliminate the formation of  H2S altogether. The economics of using our yeasts are compelling: priced in the range of other premium wine yeasts currently on the market, our yeasts prevent H2S formation, and thus improve quality at no extra cost. 

H2S masks the wine’s full flavor and quality

H2S is produced naturally as a direct byproduct of every yeast-based wine fermentation and will, even at minute concentrations below the sensory threshold of humans, affect the overall sensory quality and aroma of the wine. In industry language, the presence of H2S, even in trace amounts, “closes” the wine and hampers the full expression of its complexity.

Renaissance Yeast’s H2S-preventing yeast strains deliver the desired fermentation without this unnecessary by-product. Winemakers who use our yeasts have remarked: “My wine has never had such a remarkable aroma” and “The wine is more open.” The use of our H2S-preventing yeasts removes one key barrier to creating well-balanced, artistic and high-quality wines.

Note: Regardless of the yeast used in fermentation, elemental sulfur introduced from vineyard sprays and present on grapes at harvest time, as well as contamination by other commercial or wild yeast, can result in sulfide by-products forming in the wine. Therefore, to eliminate H2S contamination altogether, it is necessary to carefully avoid the introduction of sulfide-containing chemical sprays, as well as co-inoculation by other yeast strains that may be present in the vineyard or resident inside the winery equipment.