SCOTCH & SHERRY
The world of sherry wood
From specially commissioned seasoned hogsheads to ex-bodega butts, the world of sherry casks can be as confusing to get your head around as the varieties of sherry wine that might have filled them. In our continuing focus on sherry cask-matured whisky, Richard Goslan explores the wonderful world of sherry wood
PHOTOS: PETER SANDGROUND
You might think – given the country of origin – that Spanish oak would be the preferred wood for sherry maturation. Think again – at least when it comes to the casks used in the region’s bodegas for the long-term storage of sherry.
Casks in a bodega’s solera system, which could be used for decades, are almost exclusively American oak. They will also have already been used to ferment grape musts or to age young fortified wines before getting anywhere near a solera. That’s because sherry makers want to avoid too much wood impact or high tannin levels coming from the cask – so older and less active American oak is ideal as a long-term storage vessel.
As Gonzalez Byass master blender Antonio Flores told me on my first visit to Jerez back in 2013: “We don't want to produce what my father called a carpentry wine.”
Seasoned casks are a different story. Here, whisky distilleries – and the Whisky Team at The Scotch Malt Whisky Society – can specify exactly what kind of oak is required, how long it’s toasted for, what kind of sherry should be used for seasoning, and for how long.
From our Whisky Team’s perspective, that gives variety in terms of the kinds of casks we can work with when it comes to maturing our stocks of SMWS whisky.
“The main variables we can play with are oak species, wine type and length of seasoning,” says head of whisky creation, Euan Campbell. “So we tend to commission an equal mix of American and European or Spanish oak, seasoned equally with oloroso and Pedro Ximénez wines, with a handful of other wines on occasion.
ABOVE: Euan inspects some SMWS sherry-seasoned casks in a bodega in Jerez de la Frontera in the ‘sherry triangle’
PICTURED: Nerea Román Gil from Tevasa cooperage in front of some SMWS casks created there and now seasoning with both oloroso and Pedro Ximénez sherry
“We then draw down from these casks at different times, at between 12 and 24 months of seasoning with sherry. All this ensures that we are delivering a variety of flavours and styles, and that’s before we even consider the endless spirit types that we fill into the casks in Scotland and how long those are matured for.”
On a recent visit to Bodegas Barón, Euan and I walked between rows of sherry hogsheads, each one stencilled with SMWS lettering and indicating what kind of sherry was working its magic inside the wood.
“Right here we have 204 Scotch Malt Whisky Society casks made of American oak and 204 made of Spanish oak,” explained Nerea Román Gil. “Half of the American oak casks are filled with oloroso sherry, and the other half are filled with Pedro Ximénez – and it’s the same with the Spanish oak casks.”
According to Stuart MacPherson, former Master of Wood at The Macallan and now an independent consultant in cask management, the different wood types contribute different personalities to the whiskies that will go on to mature in those casks.
“It’s very much about the style and flavour character that you’re looking for,” he says. “If you’re looking for something that’s lighter in colour, a sweeter vanilla citrus style, then that’s more of a driver towards [American oak] Quercus alba. If you’re looking for sherry bombs that have much more dried spice and chocolatey flavours, then that’s more driven by [European oak] Quercus robur. But then you’re looking at toasting temperatures, about how you break down these chemical compounds within these species of timber to drive flavour and colour.”
ABOVE: Antonio Carrasco Gómez from Bodegas Barón prepares to draw us a sample of oloroso from one of the Society’s casks
PICTURED: Euan Campbell at Tevasa cooperage in Jerez de la Frontera, surrounded by stacks of Spanish oak air-drying in the Andalucian sun
For Stuart, toasting is also a key aspect of how the cask will go on to contribute to flavour. Unlike bourbon casks that are charred, sherry casks undergo a level of toasting that can be specified by whoever’s going to end up using the cask in question. The levels range from light, medium or heavy, but could be for between 40 and 60 minutes at a heat of around 240-250 degrees centigrade.
He says the toasting regime can play a huge role in determining the character of the cask.
“The biggest single influences on spirit development, in my opinion, are not only in wood species but in toasting temperatures,” he says. “They go hand in hand. With research and development, you can start to influence not only the flavour characteristics, but also the colour. That’s why making casks to [The Macallan’s] own specifications rather than buying them off the shelf was such a benefit for us.”
Of course, where the cask is actually going to end up is also a consideration. A one-year seasoned Spanish oak cask, for example, might work very well when it’s used in the colder Scottish climate, but would likely result in a highly tannic whisky in a hot and humid country with more intense extraction.
I’m reminded of what Miguel Martin, from Bodegas José y Miguel Martin told us about the world of sherry casks and wood varieties when Euan and I visited in 2018: “It really depends on what you’re looking for, there’s no right or wrong, no better or worse. They are just different.”