Scientists have found an unusual method to improve the quality of wine

A study conducted by Universitat Rovira i Virgili found that special yeasts can speed up the winemaking process and improve the organoleptic properties of wines. There is a growing interest in the market for carbonic maceration wines. These are young red wines characterized by dominant floral and fresh fruit aromas and are best consumed in the first year. The most famous of these wines is French Beaujolais Nouveau. However, similar traditions exist in La Rioja and Catalonia, especially in the Montsan and Conca de Barbera regions.

URV research found that the quality of these wines can be improved with the help of unconventional yeasts, which significantly increase their organoleptic properties and accelerate the malolactic fermentation process. This effect was also seen in orange and rosé wines.

Carbon dioxide maceration process

Charcoal maceration is a winemaking technique that consists of three stages. In the first case, the grapes are placed entirely in tanks filled with carbon dioxide, creating an oxygen-free atmosphere, which leads to alcoholic fermentation within the grapes. Many aromas are released during this fermentation, and the resulting wines have very fruity aromas of bananas and red berries. A few days later, in the second stage, the softened grains are pressed, completing the alcoholic fermentation. In the third and final stage, malolactic fermentation is initiated by lactic acid bacteria in the wine.

A research group from the URV Department of Biochemistry and Biotechnology has studied the effects of yeast for the first time. Torulaspora delbrueckii in wines with carbonic maceration, rosé wines and orange wines. “Previous research had focused mainly on traditional wines, whites and reds, and we were also working on other, less common types of wine. We also studied not only alcoholic fermentation, but also the entire process from start to finish,” explains Candela Ruiz de Villa, lead researcher on the project .

During the study, they inoculated yeast strains and observed how they affected the organoleptic properties and the malolactic fermentation process that occurs after alcoholic fermentation, reducing acidity and adding complexity, smoothness and stability.

Effect of the yeast Torulaspora delbrueckii

Wines obtained from this inoculation process Torulaspora delbrueckii It was quite impressive at first: “Carbonic macerated wines inoculated with these yeasts had a much more intense color than those inoculated with spontaneous yeasts, because the anthocyanins that give red wine its color were preserved.” Candela Ruiz de Villa The researchers also observed an increase in some aromatic groups, such as banana, which is the main focus of these wines.

This improvement in the organoleptic properties of wine was not the only discovery. The research team also noticed that these yeasts also shortened the overall time of the vinification process because they aided in malolactic fermentation.

The results of the study are important because they show that the inclusion of these yeasts in the carbonic maceration process may be a new way to improve the quality of wines, enrich their aromatic profiles and improve their organoleptic properties. “This process of maceration can produce high-quality wines and provides producers with a potential tool to differentiate their products in a highly competitive market,” explains researcher Nicolas Roses, who participated in the study. The results were also valid for rosé and sparkling wines.

The study was tested semi-industriously in 10-litre tanks and used in 1000-litre volumes the following year at Mas dels Frares, URV’s experimental farm. The results were the same as in the laboratory. “Yeast is already on the market. Now producers can apply it immediately because they have information they did not have before,” concludes Christina Reguant, a researcher involved in the project.