The Cuvee 407 PX has been aged in American oak casks & then further matured in rare Jerez Butts that for decades has held the unctuous & ultra rich sherry made from the Moorish Pedro Ximenez (PX) grape. Casks that held the PX grape have been revered by whisky distillers for the Madeira cake richness they bring to the maturing spirit. The ones used at the Bruichladdich distillery are extracted from the Fernanado De Castilla Solera making them the very highest in quality.