Tannin: why wine grabs your mouth

Glossary

Terms that have earned their place

Tannin

One subgroup of phenolic compounds. Tannins can interact with salivary proteins and oral surfaces, reducing lubrication and producing drying, roughing, or puckering sensations. Some can also contribute bitterness; their structure, concentration, and the wine around them affect the result.

Astringency

A tactile sensation rather than a taste. It develops when compounds including tannins interact with saliva proteins and mouth surfaces, changing lubrication. Describe its intensity, texture, onset, location, and persistence.

Phenolic compounds

A large chemical family built around one or more phenol structures—an aromatic carbon ring bearing a hydroxyl group. Wine phenolics include pigment-forming anthocyanins, tannins, flavan-3-ols, phenolic acids, and other compounds. They come mainly from grape skins, seeds, and stems, with some contributed by oak, and can affect colour, bitterness, astringency, oxidation reactions, and ageing. Not every phenolic is a tannin, and not every phenolic is directly perceptible.