Touriga Nacional (Port)

Touriga Nacional is the most prized grape in Port, and it is prized for a specific reason: it delivers colour, tannin and aroma in unusual concentration, which is what a fortified wine needs if it is to survive decades in bottle.

Port is made by arresting fermentation. Grapes are crushed and fermented for only a day or two — historically by foot-treading in granite lagares, a method that has proved so effective at gentle extraction that several producers still do it — and then neutral grape spirit is added at around seven per cent alcohol. That kills the yeast and leaves substantial sugar behind. Because the skins have had so little time in contact with the must, extraction has to be rapid and aggressive, which is why thick-skinned, deeply pigmented varieties matter so much.

Touriga Nacional contributes violet and bergamot aromatics, dense black fruit, and a firm tannic frame. It has small berries and a high skin-to-juice ratio, and naturally low yields — the vine is notoriously unproductive, which is why it was nearly abandoned before clonal selection in the 1980s made it viable again.

In vintage Port, declared only in exceptional years and bottled unfiltered after two years in cask, it is a significant component of a blend that also includes Touriga Franca, Tinta Roriz, Tinta Barroca and Tinto Cão. Those wines need twenty years and last for fifty.

Tawny Port takes a different path, ageing oxidatively in cask for ten, twenty, thirty or forty years, losing colour and gaining nut, caramel and dried fruit.