Using ΔC13 to assess viticultural and oenological suitability for Sangiovese of different pedoclimatic conditions in Chianti

Vineyard site selection and determination of adapted grape varieties for a site are the most fundamental factors contributing to vineyard success, but can be challenging to ascertain

This study investigated if compositional differences between Shiraz and Cabernet Sauvignon grape varieties could influence the production of yeast-derived compounds. This work was based on the analysis of 40 experimental red wines made in triplicate fermentations from grapes harvested from two consecutive vintages in New South Wales (Australia). Grapes were picked at three maturity stages using berry sugar accumulation as physiological indicator, from nine commercial vineyards located in three different climatic regions (temperate, temperate-warm and warm-hot). A range of 30 yeast-derived wine volatiles including esters and alcohols were quantified by HS/SPME-GC/MS. Ammonia, amino-acids and lipids were analysed in the corresponding grapes. The juice total soluble solids (°Brix) in addition to the wine alcohol and residual sugar levels were also measured. The influence of grape maturity on wine ester composition was also variety dependent, particularly for higher alcohol acetate and ethyl ester of branched acids. This study highlights that varietal differences observed in Shiraz and Cabernet Sauvignon wines involve fermentation-derived compounds irrespective of the site (soil, climate, viticultural practices).

Aim: Many processes or reactions that occur in plants involved isotopic discrimination. Water availability, for example, affects the isotopic ratio of carbon (δ13C) and oxygen (δ18O). In viticulture, δ13C is used in experiments related to water relations and irrigation in vineyards. δ18O is used much less but it could be a good complement to δ13C. The aim of this study was to generate knowledge on how these isotopic ratios, measured in musts, could help to better understand the water behavior of grape varieties. 

Climate change is drastically modifying grape composition and wine quality. As consequence, must and wines are becoming unbalanced, with high sugar concentration, increased alcohol content, lower acidity, excessive astringency, color instability and also a rise in the incidence of tartaric instability is being showed.

La Région Piemonte a commencé en 1994 un projet de caractérisation des productions vitivinicoles des terroirs du Barolo (Piemonte, Italie) par une équipe pluridisciplinaire avec la participation de 6 Instituts de recherche qui travaillent dans la Région et la collaboration de 2 Associations des producteurs viticoles et des organismes de valorisation du vin Barolo.