Garnacha Blanca

Garnacha Blanca is a white mutation of Garnacha — the same variety as Grenache Noir, with the colour switched off — and it behaves very much like its red parent: vigorous, heat-tolerant, high in sugar and low in acid.

That low acidity is the defining challenge. In hot sites and at high yields it produces a broad, soft, alcoholic wine with little definition. In the right hands it is something considerably better: full-bodied with green apple, pear and citrus, a distinctly aniseed or fennel-like herbal note, a nutty, waxy texture and a satisfying bitter finish.

Its Spanish stronghold is Terra Alta in southern Catalonia, which holds a large share of the world's plantings and has built its identity on the grape. There the wines have real weight and mineral definition, and the better producers use lees ageing, old oak or amphorae to develop texture rather than fruit.

It is also significant in Priorat and Rioja, and across the border in Roussillon and the southern Rhône, where as Grenache Blanc it is a major component of white Châteauneuf-du-Pape and of white blends throughout the Languedoc.

It oxidises readily, which producers have learned to exploit as well as guard against — deliberately oxidative, flor-aged and skin-contact versions from Catalonia have become some of the region's more interesting wines.

It is best understood as a textural grape rather than an aromatic one, and it rewards being treated that way.