Our latest single cask releases Clove Studded Oranges and Jam on Toast, were both extracted from sherry casks. We asked Isabella Wemyss, our Wemyss Malts founder to tell us more about about the influence of sherry casks on the spirit.
Sherry casks (either 500 litre butts, or 250 litre hogsheads) are one of the two main types of casks used to mature Scotch in (the other one being bourbon barrels).
Sherry used to be exported from Spain to the UK in casks for bottling, so the empty casks were used in the Scotch industry rather than shipping them back to Spain. In 1981, new regulations in Spain meant that all sherry had to be bottled there and so casks were no longer coming to the UK. Sherry casks are usually now seasoned by being filled with sherry for up to a few years in Spain, before being emptied and transported to the UK. In rare cases, a sherry cask which had previously been used to mature sherry in Jerez “bodegas” will become available, but this is usually only when the bodega has closed or there is some damage to the cask and so the Scotch industry depends almost entirely on new seasoned casks.
In choosing the style of maturation, the distiller chooses how long the sherry remains in the cask so the wood becomes impregnated with sherry and some of the harsher wood elements are removed by the sherry, rendering the cask suitable for Scotch maturation. The distiller also chooses what type of sherry is used for seasoning - from sweet Pedro Ximenez, through rich Oloroso, to the light Fino, Amontillado or Palo Cortado. Oloroso is the most common type used for seasoning, and imparts rich “Christmas cake” (dried fruit, baking spices) type flavours to Scotch.
Sherry casks can be made from either European or American oak – apart from the influence of the sherry which has previously been in the cask, this is the other main influence on flavour. European oak imparts dry and spicy tannins to the spirit, together with a darker colour; whilst American oak will impart a more golden colour and sweeter gentler flavours.
Sherry casks can be refilled with Scotch several times, and after each filling the influence of the sherry and wood will be less. This is not necessarily bad, as a light spirit may be more suited to this type of cask when it is being matured for longer as it would otherwise be overcome by all the wood influence and destroy the character of the spirit. A perfectly matured Scotch should be a balance of the influence of the cask, but the character of the spirit should still be apparent. And of course the changes which take place during a longer maturation will develop more complex flavours inviting a deeper exploration.
WRITTEN BY ISABELLA WEMYSS