Interest in measuring the grape texture to characterise grapes from different cultivation areas – Example of Cabernet franc from the Loire Valley

Due to the current challenging nature of the global wine market, and recent growth in number and strength of competitors from non-traditional wine producing countries, European wine producers are focussing on the potential to develop a competitive advantage through the concept of terroir.

In a climate change context and aiming for sustainable, high-quality Bordeaux wine production, this project examines the impact of grape maturity levels in various cultivars chosen for their adaptability, genetic diversity, and potential to enhance wine quality. The study explores the effects on wine compo-sition and quality through sensory and molecular methods. We studied eight 14-year-old Vitis vinifera cv. grape varieties from the same area (VITADAPT plots 1 and 5): Cabernet Franc, Cabernet Sauvignon, Carmenère, Castets, Cot, Merlot, Petit Verdot, and Touriga Nacional.

The elaboration of sparkling wine is a demanding process requiring technical as well as scientific skills. Uncovering the role of the terroir to the final product quality is of great importance for the wine market. Although the impact of the yeast strains and their metabolites on the final product quality is well documented, the action of bacteria still remains unknown. The malolactic fermentation (MLF) is carried out by the lactic acid bacteria after the alcoholic fermentation in order to ensure the microbial stability during the second fermentation that takes place in the bottle or in tanks. Oenococcus oeni is the only selected species to drive MLF that has been commercialized for sparkling wine elaboration and it is naturally present on grapes, in the cellar and also in the final product. However, whether the bacterial strain contributes to the sensory characteristics of sparkling wine is still questioned.

Context and purpose of the study. Climate change in many Mediterranean wine-growing regions is resulting in lower rainfall and higher reference evapotranspiration, generally leading to reduced water availability for vines.

Global warming is one of the biggest environmental, social and economic threats in several viticultural regions. In the Douro Valley, changes are expected in the coming years, namely an increase in temperature and a decrease in precipitation. These changes are likely to have consequences for the production and quality of wine.