What is astringency in wine?

Ever drunk over-brewed tea and felt like all the moisture was sucked out of your mouth? That's astringency — and it's the same sensation tannic red wines create. But unlike that over-brewed tea, in wine it can be a wonderful quality when it's well-managed.

Here's the science: tannin molecules in wine grab onto proteins in your saliva and clump them together. Your saliva normally keeps your mouth lubricated, so when tannins strip it away, your cheeks, gums, and tongue suddenly feel dry, rough, and tight. It's a physical sensation, not a flavour — which is why scientists call it a 'tactile' or 'trigeminal' perception.

Not all astringency is the same. Tannins from grape skins (especially from perfectly ripe grapes) tend to feel silky and fine — like running your hand across smooth velvet. Tannins from seeds and stems are smaller molecules that feel harsher — more like sandpaper. That's why careful winemaking (gentle pressing, avoiding seed crushing) is crucial for producing wines with 'good' astringency.

Several factors affect how astringent a wine feels. Alcohol and glycerol soften the sensation. High acidity amplifies it. Residual sugar masks it. This is why a slightly off-dry Amarone feels less astringent than a bone-dry Barolo, even though both are loaded with tannins.

Two practical solutions for overly astringent wine: time and food. Ageing allows tannin molecules to polymerise into longer chains that feel smoother. And pairing with protein-rich food (red meat, hard cheese, charcuterie) works immediately — the proteins in the food bind to the tannins before your saliva proteins do, so your mouth stays comfortable. It's one of the most reliable food-and-wine pairing principles.