Sherry casks have been used to mature whisky for as long as whisky has been matured. The fortified wine from Spain’s Jerez region is long-established as the preferred maturation cask type for legions of whisky fans.

The main types of sherry wines used to season whisky casks are Oloroso and Pedro Ximenez. Pedro Ximenez is a grape variety used to make particularly sweet, concentrated dessert wines and is one of the most popular sherry styles among whisky fans. Oloroso is a dark, dry style of aged sherry made with the palomino grape; for whisky, the Oloroso sherries are sometimes sweetened with the addition of Pedro Ximenez, a style known as cream sherry. 

Other common styles of sherry wine used to season whisky casks include Fino, Amontillado and Moscatel, though nowadays these wines seem more commonly used for finishing whiskies rather than full maturation. Sherry cask matured whiskies are renowned for rich, fruity flavours, often featuring dried fruits like raisins, prunes or dates, and usually show other characteristics including prominent nutty or chocolatey notes.