Oenological tannins are classified as hydrolysable and condensed tannins. Their use in winemaking is only authorized, to facilitate wine fining. Nevertheless, tannins could also be used to prevent laccase effects.
Many winegrape regions have hillside vineyards, where vine water use is affected by vine age, density and health, canopy size, row orientation, irrigation practices
Wine aroma is shaped by the wine’s chemical compositions, in which both grape constituents and microbes play crucial roles. Although wine quality is influenced by the microbial communities, less is known about their population interactions.
The measurement of carbon isotopic discrimination in grape sugars 13 at harvest (δ C) is an integrated assessment of water status during ripening.
Many volatile compounds of different chemical/biochemical origin contribute to wine aroma. Certain key ‘varietal’ aroma compounds such as methoxypyrazines are formed in the grape and appear to be only scarcely influenced by fermentation.