Oxidative flor ageing

Oxidative flor ageing leaves wine to mature in an unfilled barrel beneath a thin layer of yeast called the veil, or flor. This veil protects the wine from harsh oxidation while permitting a slow biological transformation. Vin jaune from the Jura, made from Savagnin, must age this way for six years and three months, developing notes of walnut and spice. Spanish Sherry undergoes a comparable process under flor.