Observation and modeling of climate at fine scales in wine-producing areas

[English version below]

L’objectif de l’étude est de mettre en évidence les différences rencontrées entre les vins Barbera d’Asti, qui sont produits en AOC. Celles-ci sont imputées aux terroirs caractérisés selon les facteurs pédologiques, climatiques, et qui conduisent à des différents potentiels viticoles et œnologiques. Il est proposé une individualisation des sous-zones.

All along the red winemaking process, many microorganisms develop in wine, some being beneficial and essential, others being feared spoilers. One of the most feared microbial enemy of wine all around the world is Brettanomyces bruxellensis. Indeed, in red wines, this yeast produces volatile phenols, molecules associated with a flavor described as “horse sweat”, “burnt plastic” or “leather”. To produce significant and detectable concentrations of these undesired molecules, the yeasts should first grow and become numerous enough. Even if the genetic group of the strain present and the cellar temperature may modulate the yeast growth rate¹ and thus the risk of spoilage, the main factor seems to be the wines themselves, some being much more permissive to B. bruxellensis development than others.

Winemaking decisions and techniques are known to affect the final aromatic composition of red wines. Winemakers put a constant effort into the improved controlling of vinification procedures to achieve better quality. Anyway an increased customer’s demand for uniqueness is often forcing them to adjust and offer new and new interesting products. To support the producers, an improved knowledge on aromatic potential as affected by classical and alternative strategies is needed.

Results indicated that cross-flow microfiltration removed similarly to fining treatments the most astringent tannins, but cross-flow microfiltration also removed up to 14 % more colour. RP-HPLC and spectrophotometric results showed that egg albumin is a softer fining treatment compared to gelatine and cross-flow microfiltration.

In the context of global change, the environmental conditions are expected to be more stressful for viticulture. The choice of the rootstock may play a crucial role to improve the adaptation of viticulture to new biotic and abiotic threats (Ollat et al., 2016). However, the selection of interesting traits in rootstock breeding programs is complex because of the combination of multiple targets in a same ideotype. In this sense, the integration of studies about the genetic architecture for desired biotic and abiotic response traits allow us to identify genomic regions to combine and those with interesting pleiotropic effects.