Phenolic maturity

They are in particularly high demand on both the German and international wine markets: deep-colored red wines that are full-bodied and rich in tannins, with a harmonious balance of acidity and astringency and a well-rounded flavor profile. Many regions in Germany are well-suited for producing such high-quality red wines—a fact that many winemakers have recognized:

35% of the vineyard area is now planted with red wine grape varieties such as Pinot Noir, Lemberger, and Dornfelder. The particular challenge in local red wine production lies in changing weather conditions, which fluctuate more widely here than in other countries. Climate change is exacerbating this situation through rising average temperatures, extreme precipitation events, or droughts lasting for months. To counter these vintage fluctuations in viticulture and better manage the complex process of red wine production in the winery, a precise understanding of the underlying mechanisms is required to adapt oenological methods.

This is where a project by the Industrial Joint Research Program (IGF) comes in, which focuses entirely on phenolic ripeness: Which phenols are present in the grape skins and seeds, in what concentrations, and how easily can they be extracted? By determining these ripeness parameters, scientists from Neustadt an der Weinstraße and Bonn aim to provide winemakers, for the first time, with tools they can use to adapt their red wine production techniques to the ripeness of the grapes. The initial goal is to characterize red wines made from grape varieties grown primarily in Germany more precisely, both analytically and sensorily. To this end, wines produced from grapes at various stages of ripeness will be examined. Based on this data, the researchers then plan to develop a decision-support system for wineries, enabling them to adjust their oenological processes so that they can produce red wines with intense color, full body, and high tannin content from grapes that exhibit varying degrees of ripeness due to weather conditions.

This will provide Germany’s 18,700 wineries—the majority of which are small family-run operations—with new methods for producing red wines that are in demand on both the domestic and international markets. Only with such high-quality products can German winemakers stand up to the global players in the wine world and successfully compete with imported red wines.