Widely regarded as the finest and most complex grape-based spirit in the world, Cognac follows rigorously strict production guidelines. It is made exclusively of wine—most commonly from Ugni Blanc—from the Charente and Charente-Maritime regions surrounding the town of Cognac in southwestern France. After a second distillation in antique copper pot stills (called charentais), the spirit is transferred to French oak barrels and aged a minimum of two years (VS). Cognac is classified by both age and region (Cru). The Grande Champagne Cru and Petite Champagne Cru, both having shallow limestone soils, are the most respected.