This bottling is aged traditionally in used American barrels for 14 years and then finished in rum casks, but these casks were seasoned by The Balvenie themselves. They selected different rums from the West Indies and poured them into new American oak to season the wood. They then take their aged whisky and finish aging in the seasoned rum casks. Incidentally, this method actually further ages the rum which they can then sell back. Classic!