Isotope composition of wine as indicator of terroir spatial variability

The goal of this work was to determine the spatial variability of terroir using the isotope composition of wine. Carbon (δ13C) and oxygen (δ18O) stable isotope composition was measured in wines from Tempranillo (Vitis vinifera L.) vineyard, located in Rioja Appellation (Spain). Stable isotope composition, leaf area, vigour, yield components, grape and wine composition were determined in a grid of 85 geo-referenced points, that was drawn across the 5 ha vineyard area. Spatial variability of δ13C and δ18O of wine was studied and the vineyard area was divided into six sub-areas for each isotope. Spatial variability of wine isotope composition could be explained by variation in soil properties of the vineyard. Isotope composition of wine was related to vegetative growth and yield components. The wine water δ18O was significantly correlated to lateral leaf area, total leaf area and vigour at harvest. Carbon isotope (δ13C) was an excellent indicator of yield per vine, cluster weight and berry weight. A significant correlation between δ13C and total leaf area/yield ratio was also observed. Significant correlation was also observed between wine water δ18O and the content of malic and tartaric acids in both grape and wine. Moreover, wine δ13C and δ18O were significantly correlated with the anthocyanins and total phenols content in grape. Colour density of wine was significantly related to wine water δ18O. Our results suggest that carbon (δ13C) and oxygen (δ18O) records in wines are useful tools to study spatial variability of terroir in viticulture.