Wine chemistry

Tannins add bitterness and astringency which acts to defend vines against pests and grazing animals.

[1] Environmental factors such as soil, rainfall and fog affect flavor in ways that can be described collectively as "character" or the French term “terroir”.

Hotter temperatures and an earlier growing season can push chemistry of berries towards higher sugar content, less acids and differences in aromas.

[14] The yeast Brettanomyces produces an array of metabolites when growing in wine, some of which are volatile phenolic compounds.

Coumaric acid is sometimes added to microbiological media, enabling the positive identification of Brettanomyces by smell.

280 nm 45 min LC chromatogram of a red wine, showing mainly phenolic compounds.
2,4,6-trichloroanisole , the chemical primarily responsible for cork taint in wines.