We begin by selecting wood that will complement the style of spirit.
Our Sherry casks are made in Jerez to exacting specifications and seasoned before being shipped to Scotland. Meanwhile, our local partners, Speyside Cooperage, help us source the highest quality ex-bourbon casks from North America.
Heavily charred or lightly toasted, American Oak or European Oak, hogshead or barrel, ex-Sherry or ex-bourbon – there are many options to consider when matching spirit to wood.
A century of experience, passed down through four generations, enables us to achieve the perfect partnership, allowing delicate, complex but balanced flavours to develop during maturation.
European oak (Quercus Robur) is traditionally used to manufacture Sherry casks. It contains a high amount of tannins, giving a spirit a dry astringency in the early stages of maturation. Over time, lignin compounds break down slowly, releasing more intense notes of spice and toffee into the spirit. Quercus Robur is a slower growing species of oak, which leads to a wide grain. This gifts a whisky a highly developed complexity and character.
American White Oak
American oak, (Quercus Alba) is high in compounds called oak lactones, which help to deliver a sweet, fragrant aroma found characteristically in American Bourbon and often described as coconut, vanilla or citrus notes. Quercus Alba is a much faster growing variety of oak, which thrives in the US climate. It has a tighter grain than European Oak, which means a spirit extracts sweet and delicate flavour compounds.
The initial fill
American Bourbon whiskey is made primarily from maize, along with a mixture of other cereals such as barley, rye and wheat. Distilled in both large column stills and pot stills, the whiskey is matured in warehouses, which can be subjected to extremes in temperature.
Sherry is a Spanish white wine which has been fortified by the addition of a spirit distilled from grapes. There are different types of Sherry, each with its own characteristics; from the light, bone-dry freshness of Fino, the robust and dark nutty character of Oloroso, through to the heavy, rich, sweet and spicy notes of Pedro Ximénez. Scotch whiskies matured in ex-Sherry casks will typically carry notes of dried fruit, spice, with a nutty character.
The size the cask affects the overall maturation of the whisky and final flavour profile. The relative surface area of the wood in direct contact with the spirit influences the speed at which flavour compounds are extracted, from the cask staves into the whisky itself.
The three most common cask sizes used for Scotch whisky maturation are butt, hogshead, and barrel.
(Volume: 500 litres). Almost exclusively ex-Sherry. This cask has the smallest surface area in contact with the liquid, resulting in the slowest maturation. This allows more time for alcohol to break down the flavour compounds, typically providing tobacco, fig, and spice flavours.
(250 litres). There are two types of hogshead casks: ‘Re-made’ and ‘Sherry’. Re-made hogshead is traditionally made by Scottish coopers by adding staves to barrels to increase the size, resulting in sweet vanilla flavours. Sherry hogshead is the smaller brother of the Sherry butt, producing similar fig and spice flavours.
(200 litres). Generally ex-American Bourbon. These casks have the largest surface area per litre, delivering faster maturation likely to yield sweet, fruity flavours.
Preparing the cask
The type of wood and how it is prepared influences the overall maturation of the whisky.
During coopering, the inside of the cask is heated which makes the wood more pliable to shaping and changes the chemistry of the wood.
Heat transforms the flavourless wood compounds into rich aromatic compounds that can be extracted during whisky maturation. The layer of carbon also filters out the undesirable flavours and compounds.
The temperature and duration of firing the cask affect the flavour development in the whisky.
We specify these variables to an exacting degree using knowledge handed down over four generations.