Charbono, the California name for the virtually extinct douce noire of the savoie region in the French Alps, also known as Corbeau and Charbonneau. Charbono clings to existence on under 100 acres/40 ha on the North Coast, especially in the Napa Valley. As varietal wine it can be difficult to distinguish from Barbera grown under similar circumstances. dna profiling has shown it is identical to the bonarda of argentina.