Trebbiano

Trebbiano Toscano, known in France as Ugni Blanc, is one of the most planted white grapes in the world and among the least celebrated. It is vigorous, high-yielding, ripens late, holds ferocious acidity and produces a wine with almost no flavour.

Those properties make it close to useless for fine wine and close to ideal for distillation. It is the principal grape of Cognac and Armagnac, where high acid and low alcohol in the base wine are exactly what the still wants, and neutrality means nothing interferes with what the oak and the ageing contribute. The overwhelming majority of the world's Ugni Blanc ends up as brandy.

As wine it is a component in a long list of central Italian whites — Orvieto, Frascati, Soave, and until 1994 it was even permitted in Chianti, a requirement that did the red wine no favours whatsoever. It contributes acidity and volume and very little else: green apple, lemon, a thin, neutral character and a short finish.

It is also the base for most Italian balsamic vinegar and, dried, for much Vin Santo.

A number of other Italian grapes carry the Trebbiano name without being related. Trebbiano Abruzzese is a genuinely distinct and far better variety capable of serious wine; Trebbiano di Soave and Trebbiano di Lugana are actually Verdicchio. The name functions more as a category than a lineage.

Its sheer ubiquity is the point: this is the grape behind an extraordinary volume of what people drink without ever seeing its name.