Wine glossary: Winemaking

Winemaking terms

Vintage

The year the grapes were harvested, shown on the label. Because weather changes each year, the vintage can affect a wine’s character.

Non-vintage

A wine, often Champagne, blended from more than one year’s harvest to keep a consistent house style. Usually shown as ‘NV’ on the label.

Oak

Barrels or staves used during winemaking that add flavours like vanilla, spice, toast or coconut, plus texture and gentle tannin. ‘Unoaked’ means none was used.

Malolactic conversion

A natural process (often called malolactic fermentation) that turns sharp malic acid into softer lactic acid, giving a rounder, creamier feel. It’s part of what makes some Chardonnays taste buttery.

Lees

The spent yeast and fine particles left after fermentation. Leaving wine to rest on its lees adds richness, texture and savoury, bread-like notes.

Fining

A gentle clarifying step where a substance is added to draw out tiny particles so the wine looks clear and bright. Some wines are ‘unfined’ and left more natural.

Fermentation

The process where yeast converts grape sugar into alcohol, turning juice into wine. It’s the heart of how every wine is made.

Noble rot

A helpful mould (Botrytis cinerea) that shrivels ripe grapes, concentrating their sugar and flavour. It is used to make rich, sweet dessert wines like Sauternes.

Late harvest

Grapes picked later than usual, so they ripen longer and build up extra sugar. That usually makes sweeter, richer wines, though some are fermented all the way dry.

Chaptalisation

Adding sugar to the grape juice before fermentation, usually where grapes struggle to ripen fully. The yeast turns that extra sugar into alcohol, so the wine ends up stronger but no sweeter.

Carbonic maceration

A method where whole, uncrushed grapes ferment from the inside out in a sealed, oxygen-free tank. It makes light, fruity, low-tannin red wines, like classic Beaujolais.

Skin contact

Letting the juice sit with the grape skins, the maceration that gives reds their colour and tannin. A short soak adds flavour and grip to whites; a long one turns them amber, making “orange” wine.

Maceration

The general term for soaking grape juice with the skins, seeds, and sometimes stems to draw out colour, tannin, and flavour, especially in reds. Skin contact is another word for it.