EVALUATION OF THE OENOLOGICAL POTENTIAL OF NEW RESISTANT VARIETIES MEETING TYPICAL BORDEAUX CHARACTERISTICS

Abstract

Varietal innovation is a major lever for meeting the challenges of the agro-ecological transition of vineyards and their adaptation to climate change. To date, selection work has already begun in the Bordeaux region through the Newvine project. The aim of this project is to create new vine varieties with resistance to mildew and powdery mildew, adapted to the climatic conditions of the Bordeaux region and enabling the production of wines that are in line with consumer tastes and the expected typicity of Bordeaux wines.

Crosses were made by INRAE Colmar and IFV (UMT Genovigne) between varieties carrying 2 genes of resistance to mildew and 2 to powdery mildew, and Petit Verdot or Cabernet Franc grape varieties. 168 genotypes resulting from these crosses were planted on a plot in the Bordeaux vineyard with 5 vine plants per genotype. This system allowed to study the monitoring of certain agronomic aptitudes for a period of 3 vintages: resistance to mildew and powdery mildiou, sensitivity to other bio-aggressors, phenology, bearing, production, maturity.

In this study, the varietal oenological potential of 168 clones (grapes, wines) has been evaluated during the 2022 vintage by integrating 1) the study of the grape ripening characteristics and the composition of musts at harvest 2) by adapting the winemaking modalities for the part of new varietal creations which have been selected for vinification 3) by assessing the sensory quality and analytical composition of the wines made from 68 varieties.

The winemaking conditions were adapted to allow the fermentative monitoring of a large number of samples (12 white clones and 56 red clones) and the production of wine according to traditional Bordeaux methods.

All of these wines have been chemically analysed and then subjected to a sensory analysis by an ex-pert panel. To assess their oenological potential, a jury of experts rated each wine sensory characteristic according to its quality, its typicality and characterized the presence of any faults. The results show a great variability between the varieties in terms of ripening profile, grape and wine composition and the diversity of sensory profiles of the wines (some atypical or marked by alterations, others presenting typicity close to the expected profiles).

This project will capitalize on the information necessary for the selection of varieties that meet the objectives and the implementation of devices to acquire the data necessary for the registration and classification of these varieties.