Climate variability and its effects in the Penedès vineyard region (NE Spain)

Clonal evaluation of winegrapes in California has not been extensive. Early selection work by Alley (1977), Olmo (unpublished data) and Goheen (personal communication) resulted in the current collection

The influence of climatic conditions on the development of the vine and on the quality of the wines no longer needs to be demonstrated at the scale of the vineyard, by the regional climatic characteristics, determining on this scale the viticultural potentialities (Huglin, 1978; Branas, 1946; Riou et al ., 1994); but also on a local scale, at the level of the basic terroir unit (Morlat, 1989), by the landscape differentiation of the natural environment inducing climatic variability within the same vineyard, and partly explaining differences in functioning of the vine, in connection with the processes of maturation and the quality of the wine (Becker, 1977 and 1984; Morlat, 1989 and Lebon, 1993a). According to these authors, the climatic diversity in a wine region constitutes in addition to the edaphic component, an important component of characterization of the Basic Terroir Units (UTB).

Dans le cadre de TerclimPro 2025, Coralie Dewasme a présenté un article IVES Technical Reviews. Retrouvez la présentation ci-dessous ainsi que l’article associé : https://ives-technicalreviews.eu/article/view/8486

Acacia senegal gum (Asen) is an edible dried gummy exudate [1] added in young red wines to ensure their colloidal stability, precluding the precipitation of the coloring matter. Asen macromolecules, belonging to the arabinogalactan-protein (AGP) family [2], are hyperbranched, charged and amphiphilic heteropolysaccharides composed especially of sugars (92-96 %) and a small fraction of proteins (1-3 %). Asen is defined as a continuum of macromolecules that could be separated into three fractions by hydrophobic interaction chromatography (HIC) [3-4]. HIC-F1 (85-94 % of Asen), HIC-F2 (6-18 % of Asen) and HIC-F3 (1-3 % of Asen) are named and classified in that order according to their protein content, and then a growing hydrophobicity. The efficiency of Asen towards the coloring matter instability is evaluated according to an “efficacy test” that consists to determine the Asen quantity required to prevent the flocculation by calcium of a colloidal iron hexacyanoferrate solution (International Oenological Codex).

In vineyards grown in warm areas, it is usual that the stage of maturity of the grapes is fast and easily reach a high concentration of sugar and low acidity, but not a adequate phenolic maturation. The geometry of the trellis system and the shoot density can modify the microclimate of the cluster and, therefore, the maturation process.