Terroir and precision viticulture: are they compatible?

AIM: Stalks are empirically known to bring many benefits to the wine such as alcoholic reduction, color protection or improvement of the tannic intensity. Not much used on Swiss grape varieties, the aim of this study was to identify the relevance of using this type of winemaking in the case of Gamay and Gamaret red grape varieties.

Pre-fermentative skin maceration is a technique used in white wine production to enhance varietal aroma, but it can increase protein concentration, leading to protein instability and haze formation [1]. To prevent protein instability, wine producers typically use fining agents such as bentonite, before wine bottling, which can negatively impact sensory characteristics and produce waste [2,3]. The aim of this study was to understand the impact of alternative techniques such as the application of polysaccharides (k-carrageenan and chitosan) on protein stability and on the wine macromolecular composition.

STICS est un modèle de culture développé à l’INRA (France) depuis 1996. Il simule les bilans de carbone, d’eau et d’azote dans le système culture-sol, piloté par des données climatiques journaliéres. Il calcule à la fois des variables agricoles (rendement en quantité et qualité) et environnementales (pertes en eau et en azote). Une des originalités de STICS est son adaptabilité à de nombreuses cultures (herbacées, ligneuses, annuelles, pérennes) rendue possible par le choix de paramètres génériques et d’options de formalismes. Le travail présenté traite, dans un premier temps, des spécificités de STICS pour la vigne en terme de bilan trophique, de fonctionnement énergétique et hydrique et d’estimation des teneurs en sucre en en eau du raisin. Nous montrons ensuite diverses sorties du modèle qui permettent de caractériser des terroirs du vignoble des Côtes du Rhône.

Climate changes and the trend towards organic and more sustainable winemaking highlighted the need to use biological methodologies. The reduction in the use of SO2, the need of the reduction of ethanol content of wines and the now need to reduce or eliminate chemical phytosanitary products, have prompted the search for alternative practices.

Rapid and accurate quantification of grape berry phenolics, anthocyanins and tannins, and identification of grape varieties are both important for effective quality control of harvesting and initial processing for wine making. Current reference technologies including High Performance Liquid Chromatography (HPLC) can be rate limiting and too complex and expensive for effective field operations