Wine Industry Embraces Sustainable Fermentation with Innovative Yeast Strain

In the wine industry, energy consumption for cooling significantly impacts production costs and the environment throughout the winemaking process. As a result, industry professionals are constantly seeking innovative approaches to save energy and reduce environmental impact. The wine industry is increasingly moving towards sustainable production, responding to growing consumer awareness and international guidelines. The OIV's 2020-2024 strategic plan emphasizes the importance of reducing energy consumption through microbiological innovation. In this context, selecting and using specific yeasts can play a crucial role in optimizing the fermentation process, helping to limit the need for cooling without compromising wine quality.

Based on these considerations, the Ever team has developed strategies to make the winemaking process more energy-efficient and sustainable while ensuring a quality product. Ever's Research and Development team conducted a study to evaluate potential energy savings through more sustainable fermentation management. The study compared different yeasts from the company's strain collection, conducting trials in primary fermentations at various temperatures. This approach allowed the identification of a yeast strain capable of adapting to a wide range of temperatures while maintaining the wine's aromatic profile almost unchanged. The selected strain, named R.E.515, highlights its resistance to different working conditions.

The study used the "Y-TEAM" approach, an exclusive method by Ever. This method involves hypothesizing the best fermentation options based on yeast knowledge and potential. The trial was conducted in Ever's laboratories with support from ITALIANA BIOTECNOLOGIE's biotechnology research and development center. The "Wine Learning" approach allows Ever to quickly develop yeasts with different enological objectives according to market needs, providing operators with valid tools in the winery. The method includes incubating micro-fermentations in 350 ml tests, duplicated, with continuous monitoring of fermentation kinetics. Fermentation kinetics are controlled by measuring the carbon dioxide produced under standardized temperature and pressure conditions. The working conditions involve comparing two fermentations with the same nutritional protocol and yeast dosage to compare only the fermentation temperatures by tracking the kinetics.

The selected yeast, Saccharomyces cerevisiae r.f. bayanus, is vigorous, expressive, and resistant to multiple stress conditions. It exhibits thermophilic behavior, performing well at high fermentation temperatures by revealing varietal aromatic precursors and completing the aromatic profile with fruity and floral esters. This yeast was isolated to produce high-quality wines while reducing the carbon footprint of wineries. It is recommended for premium white and red wines, enhancing both thiolic and terpenic varieties and more neutral ones. These characteristics make it excellent for fermenting musts from resistant grapes.

During experimentation, parallel trials compared fermentation at 17°C with that at 23°C. Analyses of samples from both trials showed equivalent results. The differences due to varying temperatures were minimal for significant enological parameters like volatile acidity, total alcohols, esters, and acetates. The alcohol content achieved was the same. It is useful to analyze more specifically the differences in aromatic quality, fermentation times, and associated energy consumption. A trial with Riesling at two temperatures, considered extreme for a white wine, summarized the most critical aromatic parameters: negative notes like high molecular weight alcohols, the sum of esters and acetates, and terpenes. Positive markers were notably high, and tasting confirmed that the wine fermented at a higher temperature was comparable or even better in all aspects.

The most significant aspect is fermentation times and energy consumption. The fermentation time in this trial, which synthesizes the results obtained and confirmed in all mentioned trials, was 7 days for tests at 23°C and 14 days for tests at 16°C. This parameter alone, with the guarantee of comparable product quality, would suffice to appreciate R.E. 515's interest. Additionally, evaluating energy benefits, without detailing specific energy balances, suggests at least a 50% energy saving. The energy released during sugar-to-alcohol transformation is the same in both fermentations, as the same matrix is used with temperature as the only differing parameter. However, there is a 50% time saving, greater efficiency in cooling unit exchange, and a net energy saving from reducing the temperature by 6°C, which is significant.

R.E. 515 has proven to be a very resistant and versatile yeast, capable of delivering excellent fermentation results even at high temperatures. All laboratory trials, continued at an industrial level in wineries, confirmed these qualities, corroborated by excellent results from winemakers who tested them. The extreme fermentation temperatures used in these trials do not aim to define a protocol but rather provide evidence that despite a 6-degree temperature difference between the two fermentations, the resulting wine is aromatically comparable and free of volatile acidity defects. Why not take advantage of this opportunity to save energy and time? Ever proposes using R.E. 515 for its contribution to the sustainability of alcoholic fermentation: a faster process that reduces environmental impact and allows greater fermenter rotation without compromising wine quality.