Effect of vine nitrogen status on grape and wine quality: Terroir study in the Vaud vineyard (Switzerland)

Oxygen is playing a major role in wine ageing and conservation. Many chemical oxidation reactions occur but they are difficult to follow due to their slow reaction times

Phenolic compounds are important quality indicators in red wine. A large number of polyphenols play an important role in wine development, contributing to the colour and the sensory perception of the wines. Anthocyanins are the pigments responsible for the colour in young red wines while tannins are the principal contributors to the bitterness and the astringency of the wines. Wine polyphenols are considered more complex molecules than grape phenolics, due to the enormous number of chemical reactions which take place during the entire winemaking process and storage, forming more stable compounds.

The addition of sulphur dioxide (SO2) is the method traditionally used for wine stabilisation, due to its broad spectrum of action against unwanted microorganisms and its ability to prevent oxidative phenomena.

Aims: This study aims to: (1) characterize the agroclimatic conditions of the Portuguese Denominations of Origin, using a compound index that combines thermal and soil water balance conditions and a high-resolution climatic dataset (~1 km spatial resolution); (2) categorize the main grapevine varieties as a function of this compound index.

Insufficient acidity in grapes from warm(ing) climates is commonly corrected through addition of tartaric acid during vinification, and less so with other organic acids. One alternative approach involves bio-acidification with certain strains of Lachancea thermotolerans (LT) via lactic acid production during fermentation.