Trebbiano is the most common name for the undistinguished Ugni Blanc grape. It has many mutations and sub-varieties such as Procanico in Tuscany and Umbria. It is so widely planted in France that probably produces more wine than other vine variety in the world. It's more often cited in DOC regulations that another other single variety and may well account for more than a third of Italy's entire DOC white wine production. The wines are generally light, white and crisp. Trebbiano (along with Malvasia) has been excluded from the official Chianti Classico DOCG composition from the 2005 vintage onwards.
Historical references to Trebbiano include Pliny ("vinum trebulanum") and Petrus de Crescenthiis in 1303, making it an ancient vine. Today, Trebbiano's principal varieties are Trebbiano Toscano, Trebbiano Romagnolo, Trebbiano d'Abruzzo, Trebbiano Giallo and Trebbiano di Soave.