Fortified wine is wine with a dose of spirit added, which is how sherry, port, madeira and marsala were made to survive sea voyages, and how vermouth and the quinine aperitifs got their strength. At 15 to 22% ABV these are the bridge between wine and spirits, and they are in more cocktails than any category except the base spirits themselves: every Manhattan, Martini and Negroni depends on one.

What is fortified wine?

Wine to which a grape spirit — usually a neutral brandy — has been added, either during fermentation, which stops it and leaves residual sugar (port, the vins doux naturels), or after it, which leaves the wine dry and then lets the maker sweeten to taste (sherry, madeira, marsala). The spirit raises the strength to 15 to 22%, which preserves the wine and lets it be aged in ways table wine cannot be. The great fortified wines were all built for export: sherry for England, port for the same, madeira for the American colonies, marsala for the Royal Navy.

Two further families are fortified and aromatised: vermouth, flavoured with wormwood and botanicals, and the quinquinas and americanos — Lillet, Cocchi Americano, Dubonnet — bittered with cinchona bark or gentian. They are wine products first and are stored and used like them.

How it's made

Each has its own method, but the pattern is the same: ferment, fortify, age. Sherry is fortified after fermentation and aged in a solera, a chain of casks blended over years, under a yeast film (fino) or in contact with air (oloroso). Port is fortified mid-fermentation to keep its sweetness and aged in cask (tawny) or bottle (vintage). Madeira is deliberately heated for months or years, which makes it nearly indestructible. Marsala is fortified and often sweetened with cooked grape must. Vermouth and quinquinas start from a finished wine, add sugar, spirit and an infusion of botanicals, and rest briefly before bottling.

What it tastes like

Everything from bone-dry and saline (fino sherry, Sercial madeira) to rich and sweet (vintage port, Malmsey madeira, cream sherry). The dry styles taste of almonds, bread, brine and oxidised fruit; the sweet ones of raisins, figs, caramel and nuts. Vermouths add herbs and bitterness; quinquinas add orange and a quinine edge. Common to all is a wine's acidity and a spirit's warmth in one glass.

Styles worth knowing

Family	Origin	In a drink
Sherry (fino to oloroso to PX)	Jerez, Spain	Sherry Cobbler, Bamboo, Adonis, a Sherry Flip
Port (ruby, tawny, white, vintage)	Douro, Portugal	Port Flip, Suburban, Port and tonic
Madeira (Sercial to Malmsey)	Madeira, Portugal	Baltimore Eggnog, flips
Marsala	Sicily	Mostly the kitchen; a Marsala Flip
Vermouth (dry, blanc, sweet)	Italy, France	Martini, Manhattan, Negroni, Americano
Quinquinas and americanos	France, Italy	Corpse Reviver No. 2, Vesper, spritzes

Which bottle to buy

Start with the three cocktail workhorses: a dry vermouth, a sweet vermouth and a fino sherry. Between them they cover the Martini, the Manhattan, the Negroni, the Bamboo and the Adonis. A tawny port and a bottle of Cocchi Americano come next. Buy small bottles where you can — half-bottles of vermouth are sold for a reason — and buy from a shop that turns stock over, because a fortified wine that has sat open on a hot shelf is already tired.

Using it in drinks

Three jobs. As a modifier, which is most of the vermouth and quinquina business: the half-ounce in a Martini, the ounce in a Manhattan. As a base for low-alcohol drinks: the Bamboo and Adonis on sherry and vermouth, the Americano on vermouth and Campari, the Sherry Cobbler, the Port Flip. And as a richness in old recipes: madeira in the Baltimore Eggnog, port in the Suburban, sherry in a flip.

Because the strength is low, these drinks can be long and generous without doing damage. That is their virtue and the reason the aperitivo hour exists.

Substitutes

Within the family, generously: a blanc vermouth for Lillet, a fino for a manzanilla, a tawny port for a sweet madeira in a flip, an amontillado for a tawny in a stirred drink. Across the family, carefully: a sweet vermouth can replace a ruby port in a pinch, and an oloroso can stand in for a sweet vermouth's weight with a dash of syrup. Table wine does not substitute; it has neither the strength nor the oxidised depth.

Storage

These are wine. Once opened, refrigerate them and drink them within weeks — a month for vermouth and fino, a few weeks for the quinquinas, two or three months for tawny port and oloroso, and for madeira, which has already been cooked, years. Unopened, store them upright and cool; vintage port is the exception and lies down like table wine. A tired fortified wine is the most common reason a stirred cocktail disappoints.

Questions

What is the difference between fortified and aromatised wine? Fortified means spirit has been added. Aromatised means botanicals have too. Vermouth and the quinquinas are both; sherry and port are fortified only.

Does fortified wine go off? Yes, once opened, by oxidation — faster than people expect. Keep it cold and finish it within weeks. Madeira is the one that does not care.

Why is vermouth stored in the fridge but port on the shelf? Both should be refrigerated once open. Tawny port and oloroso are more oxidation-tolerant and last longer, but the fridge still helps.

Can I make a cocktail with fortified wine as the only alcohol? Yes — the Bamboo, the Adonis, the Sherry Cobbler and the Americano are all built that way, and all sit around the strength of a glass of wine.