Wine glossary: Winemaking

Winemaking terms

Appassimento

Drying grapes after harvest so they lose water and concentrate their sugar and flavour. It is how Amarone is made.

Barrique

A 225-litre oak barrel, the standard size in Bordeaux. Small, new barrels give more oak flavour than large or old ones.

Bâtonnage

Stirring the lees (spent yeast) back into the wine to add creaminess and body. Often used for white Burgundy.

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.

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.

Cork

Stoppers made from the bark of the cork oak. A small share of natural corks carry TCA, the taint that makes a wine smell corked.

Disgorgement

Removing the plug of yeast sediment from the neck of a traditional-method sparkling wine, usually after freezing it, before the final cork goes in.

Dosage

A little sweetened wine added to sparkling wine after disgorgement. How much is added decides the style, from Brut Nature to Doux.

Fermentation

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

Filtration

Passing wine through a filter to remove yeast and particles before bottling. Unfiltered wines skip this step and can look slightly hazy.

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.

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.

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.

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.

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.

Must

Freshly crushed grape juice, with its skins, seeds and pulp, before or during fermentation.

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.

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.

Organic wine

Wine made from grapes grown without synthetic pesticides, herbicides or fertilisers. The rules for what may be added in the cellar, such as sulphites, differ between countries.

Pét-nat

Short for pétillant naturel: a lightly sparkling wine bottled before its first fermentation has finished, so that fermentation makes the bubbles. Often a little cloudy.

Phylloxera

A tiny aphid-like insect that feeds on vine roots. It destroyed most of Europe’s vineyards in the late 1800s; most vines today are grafted onto resistant American rootstocks.

Racking

Moving wine from one container to another to leave the sediment behind.

Riddling

Gradually turning and tilting bottles of traditional-method sparkling wine so the yeast sediment slides into the neck, ready to be removed.

Saignée

French for “bleeding”: drawing off some pink juice early from a red-wine tank. The juice becomes rosé, and the red left behind gets more concentrated.

Screw cap

A metal twist-off closure that cannot cause cork taint and keeps wine fresh. Widely used in New Zealand and Australia, on fine wines as well as everyday ones.

Secondary fermentation

A second fermentation. In sparkling wine it is the one that makes the bubbles. Confusingly, malolactic conversion is sometimes called this too.

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.

Solera

The blending system used for sherry, where younger wine tops up older barrels year after year, so each bottle is a mix of many ages.

Stainless steel

Tanks that add no flavour and keep air out, so the wine stays fresh and fruity. Used for crisp, unoaked whites and rosés.

Sulphites

Sulphur compounds that protect wine from spoiling. A little forms naturally during fermentation and most winemakers add more. In the EU and the US, labels must say “contains sulphites” above 10 mg per litre.

Tank method

Making sparkling wine with the second fermentation in a large pressurised tank instead of in each bottle. Also called the Charmat method; used for Prosecco, it keeps the fruit fresh.

Vegan wine

Wine made without animal products. Some wines are fined with egg white, gelatine, casein (from milk) or isinglass (from fish); vegan wines use clay or pea protein instead, or skip fining.

Véraison

The point in summer when grapes soften, change colour from green to red or gold, and start building sugar.

Vintage

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

Wild ferment

A fermentation started by the yeasts naturally present in the vineyard and winery instead of added, cultured yeast. Also called a natural or spontaneous fermentation.

Yeast

The microscopic fungus that turns grape sugar into alcohol and carbon dioxide. Winemakers either add a cultured yeast or let the wild yeasts already on the grapes and in the cellar do the work.

Yield

How much fruit a vineyard produces, measured per hectare or per vine. Lower yields usually mean more concentrated grapes.