Heat berry: the influence of abiotic factors on the composition of berries, must and wine in Vitis vinifera L. CV Riesling

The market share of Rosé wine in France has grown from 11 % to 32 % over the last 20 years. Current trends are towards rosé wines of a lighter shade of pink, and where possible, containing a greater concentration in varietal thiols. Grape varieties, the soil on which they are grown, viticultural practices and winemaking technology all impact the polyphenols, color and aromas of rosé wines.

Implementing alternative grapevine systems that incorporate sustainable strategies and innovative farming practices is essential. However, we lack tools for measuring the impact of these new practices on the overall sustainability of vineyards. DEXi PM Vigne (Gary et al., 2015) is a tool developed for ex ante assessment of the sustainability of grapevine cropping systems, from the plot to the farm scale. In the present study, we focused on implementing new strategies of integrated crop protection management with limited pesticide use in vineyards.

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).

Planting vineyards in cooler climates has been used over recent years as
a strategy to counter the climatic shifts caused by climate change. A move towards higher altitudes in hilly and mountainous wine regions may provide a solution to deleterious effects that increased ambient temperatures have on wine quality. Until now, the influences of higher altitudes and their climates, as well as their effect on vine growing cycles, still holds a lot of scientific uncertainty. The transnational EU-funded project REBECKA (Interreg V-A IT-AT: ITAT1002, duration: 2017-2019) has the objective to develop a regional valuation method to rate the suitability for viticulture in South Tyrol (Italy) and Carinthia (Austria). Preliminary surveys were performed regarding the effects of altitude on ripening performance of the cultivar Pinot Noir.

The characterization of « the soil effect » in vine growing is often limited to the description of the physical components of the terroir. Many works were done in this direction and corresponded to geological, pedological or agronomical approaches. However, if the physical environment influences the vine and its grapes, its effect becomes limited at the scale of exploitation. Thus, it could be important to consider how the viticulturist « translated » the potential.