Viñedos de la D.O. Ribeira Sacra: heterogeneidad varietal y sanitaria

The French vine selection partners network is currently made up of 40 regional partners, grouped around IFV (French Institute for Vine and Wine) and INRAE (national research institute for agriculture and environment), whose missions are preservation, selection, and innovation of our varietal diversity. The originality of this device is based on a 3-level organisation: – varietal diversity preservation, with the world reference: the INRAE’s vine genetics resources centre of Vassal-Montpellier (Marseillan, France), the world’s largest ampelographic collection, which includes nearly 6 000 accessions of cultivated Vitis vinifera from 54 countries, as well as rootstocks, interspecific hybrids, wild vines (lambrusques) and wild American and Asian species.

Right after serving a sparkling wine into a glass, thousands of rising and bursting bubbles convey gas-phase CO2 and volatile organic compounds (VOCs) in the headspace above the champagne surface, thus progressively modifying the gaseous chemical space perceived by the consumer [1].

The AOC Gaillac area is divided into three main terroirs : « The left bank terraces », « The right bank coteaux » and
« The plateau Cordais ». This division is valid at a regional scale, but it suffers of a number of local-scale exceptions. This spatial variability of the pedologic-geologic characteristics at the plot scale has been derived mainly from the main late-Würmian solifluxion phase occurring at the transition between the peri-glacial climate and the Holocene temperate conditions (13,000-10,000 yrs BP).

The notion of «terroir» refers to the link between the composition, quality and taste of a wine, on the one hand, and its place of origin, on the other. It involves, among other things, the signature of soil elements, as well as the influence of climatic conditions and plant material used. The composition of the wine is also influenced by the winemaking, storage and bottling processes. We were lucky enough to have a time series of the same champagne, from the end of the first world war to the present. On this exceptional time series, we followed, with the most advanced methods, all the elemental signatures by isotopic multi-dilution, the evolution of the isotopic ratios of heavy elements with very high precision of Sr, Pb, B and Cu.

The grape maturation process is being affected by the consequences of global climate change and, as a result, there is a gap at harvest time between the technological maturity of grapes (mostly the concentration of sugar and acids) and its phenolic quality. Due to this gap, the wines elaborated using those grapes show a non-adequate phenolic composition, which results in defects on its color and astringency characteristics. Astringency is mainly related to the salivary protein precipitation because of the interaction not only with wine flavanols but also with other wine phenolics, such as flavonols or different pigments.