Rapid optical method for tannins estimation in red wines

In wine growing regions around the world, climate change has the potential to affect vine transpiration and overall vineyard water use due to related changes in atmospheric demand and soil water deficits. Grapevines control their transpiration in response to a changing environment by regulating conductance of water through the soil-plant-atmosphere continuum. Most vineyard water use models currently estimate vine transpiration by applying generic crop coefficients to estimates of reference evapotranspiration, but this does not account for changes in vine conductance associated with water stress, nor differences thought to exist between varieties. The response of bulk stomatal conductance to daily weather variability and seasonal drought stress was studied on Cabernet-Sauvignon, Merlot, Tempranillo, Ugni blanc, and Semillon vines in a non-irrigated vineyard in Bordeaux France. Whole vine sap flow, temperature and humidity in the vine canopy, and net radiation absorbed by the vine canopy were measured on 15-minute intervals from early July through mid-September 2020, together with periodic measurement of leaf area, canopy porosity, and predawn leaf water potential. From this data, bulk stomatal conductance was calculated on 15-minute intervals, and multiple regression analysis was performed to identify key variables and their relative effect on conductance. Attention was focused on addressing multicollinearity and time-dependency in the explanatory variables and developing regression models that were readily interpretable. Variability of vapor pressure deficit over the day, and predawn water potential over the season explained much of the variability in conductance, with relative differences in response coefficients observed across the five varieties. By characterizing this conductance response, the dynamics of vine transpiration can be better parameterized in vineyard water use modeling of current and future climate scenarios.

Interest in the pairing, or matching, of wine with music goes way back, with commentators initially using musical metaphors merely to describe the wines that they were writing about. More recently, however, this has transformed into a growing range of multisensory tasting events in which wine and music are deliberately paired to assess, or increasingly to illustrate, the impact of the latter on

The wine-making process generates numerous by-products at each stage (crushing, fermentation, ageing), including wine lees, which account for almost 25% of the total quantity.

La composition du raisin de la variété Muscat d’Alexandrie a été étudiée dans trois terroirs différents au Nord-Est de la Tunisie (RafRaf, Baddar et Kelibia).
Des échantillons de raisins ont été récoltés à maturité industrielle durant les saisons 2001 et 2002 dans les trois régions citées. Les paramètres pomologiques (poids moyen de la grappe et de la baie) et physico-chimiques

The chemistry of wine is notably complex and is modified by ageing of the bottles. The composition of wines is the result of vine production (under the influence of vintage, climate and soils); yeast production (under the influence of juice composition and fermentation management); lactic bacteria production (under the influence of young wine composition and malolactic fermentation management); and of the ageing process either in vats, barrels or bottles or both. The composition is linked to the quality perceived by consumers but also to their origin, sometimes associated to the “terroir” concept.