The influence of culture medium on the dynamics of fermentation of wine yeasts

The terroir offers great variability in the typicity of the wines produced. Following tastings integrating several vintages, the multiple factor analysis of the sensory data revealed a group of taste criteria contributing to the notion of “Power”, referenced “Power and Harmony”, which makes it possible to differentiate wines from various terroirs of the Middle Loire Valley (Pages et al ., 1987).

Botrytis cinerea is a necrotrophic pathogen that causes one of the most serious diseases of the grapevine (Vitis vinifera), grey mold or Botrytis bunch rot. In Champagne, the Botrytis cinerea disease leads to considerable economic losses for winemakers and wines exhibit organoleptic defaults.

Context and purpose of the study climate change is impacting wine typicity across the globe, raising concerns in wine regions historically renowned for the quality of their terroir. Replacing some of the plant material can be an efficient lever for adapting to climate change. However, the change of cultivars also raises questions about the region’s wine typicity. This study, based on seven years of data, investigates the potential adaptability of over 50 different varieties in the bordeaux wine region.

Vineyards from mild temperature, high humidity locations receive often treatments with fungicides to prevent damages produced by fungi responsible for mildium, oidium and botrytis infections. In addition, insecticides are also applied to vineyards to fight again pests, which affect directly, or indirectly (as vectors of different diseases), their productivity. A fraction of the above compounds reaches the soil of vineyards, either during application, or when released from the canopy of vines due to rain-wash-off. Thereafter, depending on soil conditions (pH, organic matter) and environmental variables (regimen of rain, slope of vineyards), they might persist in this compartment, be degraded and/or transferred to water masses, modifying the biodiversity of soils and/or affecting the quality of water reservoirs.

Sulfur-like off-odours are a problem caused by the presence of free forms of volatile sulphur compounds (VSCs). H2S is the most frequently found above its odour threshold