Alternative yeasts open new perspectives for winemakers

Yeast has been a key component in winemaking for centuries, yet today the industry relies mainly on commercial cultures of Saccharomyces cerevisiae. A PhD study by Madina Akan at the Vrije Universiteit Brussel and Hochschule Geisenheim University now shows that lesser-known, so-called non-conventional yeasts (NCYs) offer surprising opportunities to make wines both more aromatic and lighter in alcohol.

In her research, Akan studied yeasts from natural environments as well as yeasts developed through hybridization or genetic techniques. These alternative yeasts proved capable of influencing a wine’s aroma, flavor complexity, and even alcohol content in a natural way. In doing so, they respond to the growing demand for refined wines with lower alcohol levels.

One striking discovery was the role of terrestrial snails in the spread of wild yeasts. A wide variety of yeast species were found on snails, including wine yeasts with potential applications in fermentation. This points to an unexpected ecological link in the transport of microorganisms.

Akan also investigated Saccharomycopsis fermentans and specific mutants that strongly affect wine aroma through the production of higher alcohols such as isoamyl alcohol. In controlled amounts, these compounds can contribute to a complex and fruity aromatic profile. In addition, she developed a new, efficient method to enable genetic modifications in lager yeasts, with broad industrial applications.

Finally, she created new yeast hybrids between Saccharomyces jurei and S. cerevisiae. In co-fermentations, these hybrids produced wines with a lower alcohol content and a rich, innovative aroma. According to her supervisors, the research confirms that non-conventional yeasts offer winemakers valuable new tools to better control both flavor and alcohol levels.

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