Touriga Nacional

Touriga Nacional is Portugal's most prized red variety and the backbone of the finest Port, though it now makes as much unfortified wine as fortified.

Its strength is concentration. The berries are small and thick-skinned, giving an exceptional skin-to-juice ratio and therefore deep colour, substantial tannin and intense aroma. The signature is floral — violet and bergamot, sometimes described as orange blossom — over dense black fruit, with liquorice, mint and a resinous, pine-like note.

It was nearly abandoned for a practical reason: the vine is vigorous and produces very small crops, with the vegetation outgrowing the fruit. Growers found it uneconomic, and by the 1970s plantings had fallen sharply. A clonal selection programme at Dão in the 1980s produced more balanced material and the variety recovered.

In the Douro it is one of five principal Port grapes, valued above the others for the aromatic intensity and structure it contributes. The same qualities have made it central to the Douro's growing production of dry table wine, an activity that barely existed before the 1990s and now accounts for a substantial share of the region's output.

Dão, higher and granitic, produces a more elegant and perfumed style with finer tannin. It is also planted across Portugal and increasingly in Australia, South Africa and California, where its drought tolerance is an asset.

It is one of relatively few varieties that can carry an entire wine alone while also being at its best in a blend.

Its transformation from Port grape to table-wine grape is one of the more significant shifts in European wine over thirty years. The Douro produced almost no dry red of consequence before the 1990s; it now makes some of Portugal's finest, and Touriga Nacional is usually the backbone.

The vine's natural unproductiveness is the reason it nearly disappeared and the reason its wines are concentrated. It puts its energy into vegetation rather than fruit, and growers historically found the economics impossible. Clonal selection at Dão in the 1980s produced more balanced material without losing the concentration.

Its violet-and-bergamot perfume is the clearest marker in blind tasting, and it survives both fortification and long oak ageing, which is unusual — most aromatic varieties lose their signature under that treatment.