How Wine Is Made, From Vine to Bottle

Wine is grape juice that yeast has turned into alcohol. Everything else — the colour, the grip, the price, the reason one bottle tastes of blackcurrant and another of lemon — comes from decisions made around that one reaction.

The single most useful thing to understand is that red and white wine are made in the opposite order. Whites are pressed and then fermented. Reds are fermented and then pressed. Almost every difference between them follows from that.

The whole process in six steps

1. Growing — a year of work in the vineyard that decides most of the quality.
2. Harvest — picking at the moment sugar, acidity and flavour are best balanced.
3. Crushing and pressing — separating juice from skins, in an order that depends on the colour you want.
4. Fermentation — yeast converts sugar into alcohol and carbon dioxide.
5. Ageing — resting in steel, concrete or oak while the wine settles and develops.
6. Bottling — with a closure chosen for how long the wine should keep.

Steps one and two happen outdoors and take a year. Steps three to six can be over in weeks. Most people picture winemaking as step four; growers will tell you the wine was largely decided by step two.

It starts in the vineyard, not the winery

A vine repeats the same cycle annually. Budburst in spring pushes out the first shoots. Flowering follows, and every flower successfully pollinated becomes a grape — which is why bad weather during this brief window can halve a crop before summer begins.

Then comes veraison, the moment growers watch for: the hard green berries soften, red grapes change colour, and the vine stops building itself and starts loading the fruit with sugar.

Between those milestones is constant work. Winter pruning cuts the vine back to a small number of buds, deciding in advance how much fruit it will carry — fewer bunches, more concentration in each. Through summer, leaves are positioned or removed to control how much sun and air reach the grapes. In a cool damp region that means more exposure for ripeness and dryness; in a hot region the same move would sunburn the fruit, so the leaves stay on as shade. The same grape behaves differently in different places partly because the grower is making opposite decisions.

Harvest: the year's most nerve-racking decision

Three things move at once as grapes ripen, and they rarely peak together.

Sugar rises, which sets the eventual alcohol. Acidity falls, and acidity is what keeps a wine tasting fresh rather than flabby. And flavour ripeness develops on its own schedule — the point where tannins soften and the fruit tastes complete rather than green. Pick early and the wine can be lean and green; pick late and it can be heavy and hot. Our guide to wine alcohol content covers why warm regions push that balance around.

Then there is the practical question of how. A machine straddles the row, shakes the berries loose, and can work at night when the fruit is cool — fast and cheap, but it cannot tell ripe from unripe, and it delivers loose berries rather than whole bunches. Hand-picking is slow and costly, but pickers can leave bad fruit behind and the bunches arrive intact. Some rules require it: Champagne must be hand-harvested because whole-bunch pressing is mandatory, and loose machine-picked berries make that impossible. On the steep terraces of the Mosel, no machine can go anyway.

White wine: press first, ferment cool

The defining move happens within hours of picking — the juice is separated from the skins straight away.

Because it never soaks with them, it takes on no colour and virtually no tannin. That is why white wine is pale and has no grip, whatever grape it came from.

Fermentation then runs cool, often around 12–18°C, over a couple of weeks. Cool and slow protects the delicate citrus and floral aromas that heat would drive off, which is why most whites ferment in stainless steel. Richer styles go into oak instead — our guide to French versus American oak explains what that adds.

Afterwards the winemaker chooses how much texture to build: leaving the wine on its spent yeast lees gives a creamier feel, and malolactic conversion turns sharp malic acid into softer lactic acid. An unoaked, unmalo Chardonnay and a fully oaked one are the same grape treated in opposite ways.

Red wine: ferment first, press after

Reds invert the sequence. Crushed grapes go into the tank as a mixture of juice, skins and pips, and fermentation begins with everything together.

All the colour, tannin and structure are pulled out of those skins during this period, called maceration, which can run from a few days to several weeks. Fermentation is warmer than for whites, typically around 25–30°C, because heat helps extraction.

As it works, carbon dioxide pushes the skins up into a floating cap on top of the liquid. Left alone it dries out and stops contributing, so it has to be mixed back in constantly — either by pumping juice over the top or physically punching the cap down. How often, and how gently, is one of the real levers a red winemaker has: more working means more colour and more grip.

Only when the extraction is judged right is the wine pressed off the skins.

Everything else is a variation on those two

Rosé is made from dark grapes given only brief skin contact — hours rather than days — so it takes colour without much tannin.

Sparkling wine is a finished still wine given a second fermentation in a sealed container, trapping the carbon dioxide. Do it inside each bottle and you get the fine, bready character of Champagne; do it in a pressurised tank and you keep the fresh grapey aromatics of Prosecco.

Sweet wines keep sugar the yeast never converted, either by stopping fermentation early or by starting with grapes so concentrated the yeast cannot finish — dried, frozen, or shrivelled by noble rot, as in Sauternes. Fortified wines like Port have grape spirit added, which stops fermentation and leaves sweetness behind.

And orange wine is the neat inversion: white grapes fermented on their skins like a red, which is exactly why it has tannin.