The tart, mouth-watering freshness in a wine. It makes you salivate and keeps a wine lively, and it is highest in grapes from cool places.

Appellation d'Origine Contrôlée, France's system of protected wine origins, set up in 1935. AOP is the equivalent EU term now used on labels.

Drying harvested grapes on racks or mats for weeks or months before fermenting, concentrating sugars and flavours. It is the method behind Amarone.

A legally defined wine region whose name on the label guarantees where the grapes were grown, and often which grapes, yields and methods were used.

The art of blending different grapes, vineyards or batches into the final wine. A cuvée is a particular blend or batch.

The harmony between a wine's fruit, acidity, tannin, alcohol and sweetness, where nothing sticks out and everything supports the rest.

Stirring the lees back through the wine in barrel or tank, to build richness and a creamy texture and to protect the wine from oxidation.

A holistic, organic-plus approach to farming based on Rudolf Steiner's 1924 lectures, using herbal and mineral preparations and following a calendar of lunar and cosmic rhythms.

The weight and fullness of a wine in the mouth, from light, like skimmed milk, through medium to full-bodied, like whole milk.

A beneficial fungus, also called noble rot, that dries out ripe grapes on the vine, concentrating their sugar and acidity into intensely sweet wine.

A wild yeast that can give a wine "barnyard", horse-sweat, leather and smoky aromas. Barely present it adds character, but in quantity it is a fault.

Shaping the leaves and shoots of the vine, by trimming, tucking and removing leaves, to control sunlight, airflow and disease pressure around the fruit.

Fermenting whole, uncrushed bunches in a sealed, carbon-dioxide-filled vessel, so fermentation starts inside each berry. It gives bright, juicy, low-tannin reds.

Adding sugar to grape juice before or during fermentation to raise the finished alcohol. It adds strength, not sweetness.

In Burgundy, a precisely delimited, individually named vineyard plot with its own soil and exposure, each with a distinct identity.

A group of vines propagated from cuttings of one selected parent vine, so they are genetically almost identical and share its traits.

The presence of many different layers of aroma and flavour, ideally ones that shift and reveal more as the wine sits in the glass.

A wine region with a low average growing-season temperature, where grapes ripen slowly and wines are typically lighter, higher in acidity and lower in alcohol.

A fault, caused mostly by a compound called TCA, that gives a wine a smell of damp cardboard or a wet basement and mutes its fruit.

French for "growth": a vineyard or estate recognised for its quality. What the word means depends on the region, so it always needs its context.

The gap between the warmest part of the day and the coolest part of the night. Big swings let grapes ripen in the sun and hold their acidity and aromatics in the cold.

Italy's two tiers of protected origin. DOCG (the G is for garantita, guaranteed) is the higher one, with stricter rules and a tasting panel.

The small addition of wine and sugar made to a sparkling wine after disgorgement, which sets its final sweetness, from bone-dry Brut Nature to noticeably sweet.

A wine with no noticeable sweetness, as almost all the grape sugar has fermented into alcohol. It does not mean tannic or astringent.

The process in which yeast turns the sugar in grape juice into alcohol and carbon dioxide. It is what makes grape juice wine.

How long the flavours of a wine last after you swallow. A long, evolving finish is one of the clearest marks of quality.

Wine with a neutral grape spirit added to raise its alcohol, typically to 15–22%. Port, Sherry, Madeira and Marsala are the classics.

The top rungs of a vineyard classification. In Burgundy, grand cru is the highest tier and premier cru the next, ranked by the site itself and not the producer.

Sweet wine made from grapes left to freeze on the vine and pressed while still frozen, so only the concentrated, sugary juice runs out.

The spent yeast cells and fine particles that settle after fermentation. Ageing a wine on its lees, or sur lie, adds texture and savoury, bready flavours.

Soaking crushed grapes in their juice so the skins give up colour, tannin and flavour. It is why red wine is red and white wine usually is not.

A second, bacterial fermentation that converts sharp, green-apple malic acid into softer, creamier lactic acid, making a wine rounder and less tart.

A tasting word for stony, flinty, saline or wet-rock sensations, most often used for crisp whites from poor soils, like Chablis and Mosel Riesling.

The smell of a wine, taken by swirling the glass and sniffing. Tasters describe intensity, the aromas they find and how developed they are.

Maturing wine in oak barrels, which lets in a little oxygen and adds flavours of vanilla, spice, toast and cedar, along with tannin.

Vines of considerable age, often 30 to 50 years or more. They crop lightly and reach deep for water, and are prized for concentrated, layered wines.

A shorthand split. The Old World is Europe's long-established wine countries; the New World is everywhere wine arrived later, such as the Americas, Australasia and South Africa.

The effect of too much oxygen on a wine, dulling the fruit and giving flat, bruised-apple and nutty smells. It is a fault when unintended and a style when deliberate.

What a wine does in the mouth: its sweetness, acidity, tannin, body and flavours. Also the taster's own sensitivity to those things.

A tiny root-feeding insect that destroyed much of Europe's vineyards from the 1860s. The cure was grafting European vines onto resistant American rootstocks.

Germany's quality ladder, based on how ripe the grapes were at harvest: Kabinett, Spätlese, Auslese, Beerenauslese and Trockenbeerenauslese, with Eiswein alongside.

A large, egg-shaped clay vessel buried in the ground, in which Georgian growers ferment and age wine, often on the skins.

Label terms in Spain, Portugal and Italy for wines given extra ageing before release. The exact minimums are set by law and differ by region.

The natural grape sugar left unfermented in a finished wine, measured in grams per litre. It sets how sweet the wine tastes.

The root system a wine grape is grafted onto. It is chosen for resistance to pests and drought, tolerance of chalky soil and how vigorously it drives growth.

French for "bled": running off some of the juice from a red ferment early on to make the rest more concentrated. The pink juice can become rosé.

Fermenting white grapes on their skins, as a red would be. The result, often called orange or amber wine, is deeper in colour, savoury and lightly tannic.

A system of fractional blending in which a little of the oldest wine is drawn from a tier of barrels and topped up with younger wine from the tier above.

The framework of a wine: its acidity, tannin, alcohol and body, which shapes how it feels and how well it will age.

Making sparkling wine by carrying out the second fermentation in a large pressurised tank instead of in each bottle. It keeps fresh fruit and costs less.

A compound from grape skins, seeds and stems (and oak) that makes a wine feel drying and grippy in the mouth, like strong black tea.

The combined influence of a place — its soil, climate, slope and aspect — plus the human traditions of the people who farm it, on the character of a wine.

The savoury, dried and nutty scents that appear as a wine matures, such as leather, mushroom, honey, dried fruit and toast. Primary aromas come from the grape, and secondary aromas from winemaking.

Making sparkling wine by a second fermentation inside the bottle it is sold in, then ageing on the lees. It is how Champagne is made.

The moment ripening begins: grapes soften, red varieties change colour from green to red or purple, sugars climb and acidity starts to fall.

The year the grapes were harvested, shown on the label. Weather varies year to year, so vintage tells you a lot about a wine, especially in cool regions.

The presence of acetic acid (vinegar) and related compounds, smelling of vinegar or nail-polish remover. Small amounts are normal, and large ones spoil the wine.

Fermenting grapes with their stems still attached rather than removing them first. The stems add structure, spice and aromatic lift.

How much fruit a vineyard produces, measured in tonnes per hectare or, for wine, hectolitres per hectare (hl/ha).