Calvados 20 ans has been aged for at least 20 years in a wooden vat and toasted oak barrels. The apples are mixed, crushed and pressed. The apple juice is fermented right out to give cider to be distilled. Double distillation is carried out 6 months after the fermentation has taken place. The first distillation gives the "petite eau" at 30% by volume and it is the second distillation, that of the "petite eau" which gives the Calvados.