Sherry casks are most commonly used to age Spanish wines, particularly those from the Jerez region. The wood for these casks is usually cut from European oak trees. Sherry casks are unique in that they add a certain flavour profile to the whisky that is difficult to replicate with other types of wood.
Sherry casks add a variety of flavours to whisky, including notes of vanilla, nuts, chocolate, and fruit. The flavour profile of a sherry cask whisky will depend on the type of sherry cask that was used to age the whisky. For example, a whisky aged in an Oloroso sherry cask will be more full-bodied with sweeter notes, while a whisky aged in a Fino sherry cask will have dry, crisper notes.
Find some of the best, independent, sherry cask whiskies here.