Isabella Wemyss, our Director of Production, shares about the Solera System of sherry maturation and why we love using these casks to mature our whisky.
There are three main influences on cask character – the wood itself, what the cask has previously contained, and for how long it was previously used. Scotch is usually matured in casks which have previously contained another product, generally bourbon or sherry; and the influence of the wood itself is diminished over the time it is used as the spirit soaks up the wood flavours.
The decision as to what type of cask to mature each spirit in is an important part of the process – and for us this is particularly important due to the light, fruity, elegant, and typically Lowland character of our spirit. We are very anxious to preserve this character so that the spirit as well as the wood characters are evident in the final product.
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” under the “solera” system will become available, but this is usually only when the bodega has closed, or the casks are no longer suitable for maturation - these casks give the sherry producer the “DNA” of the sherry character, and therefore they are reluctant to let go of them. The Scotch industry therefore depends almost entirely on new seasoned casks. We have been very fortunate to source ex-solera casks for our whisky which have previously been used for many, many years to mature sherry.
In the solera system, casks are stacked on top of one another with the top casks containing the youngest spirit and the bottom casks containing the oldest spirit. Spirit for bottling is drawn off the lowest level of casks, with the headspace being filled by spirit from the casks above and henceforth all the way to the top where new spirit is added.
As these casks have contained sherry for so many years, the harsher and more intrusive wood elements have been removed far more effectively than by seasoning new casks for six months. This is why they are so suited to our spirit: the sherry influence is very definitely present, rather than the wood of the cask itself, but so also is the fruity light character of our spirit. We have designed our releases to be refined and elegant, approachable yet sophisticated. We believe that these old, well-used casks are central to this ambition, and we are excited about the cask & spirit interaction already producing the complex flavours that we had planned from the beginning.