After double ageing, the signature process of Dewar’s, the whisky is separated into two batches: the first is finished in sweet Oloroso sherry casks, the second in peaty Islay whisky casks. The liquids are then blended together again.
This finishing gives the whisky an unexpected sweet and smoky flavour: A balance of the sweetness of sherry casks with the smoke of Islay casks.