When it comes to whisky, the spirit itself—how long it’s aged and the craft behind the blending— usually gets all the hype. In fact, though they aren’t as appreciated, the wood barrels that age the liquor before its bottled are just as important as what’s inside. According to cask makers, they’re crucial to a whisky’s character and making them is an artistic craft.
The Macallan, the nearly two century-old Craigellachie, Scotland-based distillery, says its casks are key to the finish of its famed whisky—so much so that in 2012, the company appointed skilled cooper Stuart MacPherson, 52, to be its first Master of Wood. Today, MacPherson lives in the Scottish countryside and is the head of a team that includes 16 coopers who construct new barrels, seven who work solely on repairing broken ones, and three apprentices who are learning the trade.
Below, a condensed conversation with MacPherson.
What does a Master of Wood do?
I’m responsible for the supply as well as the repair of all of our casks and am involved with our education program around wood and its influence on the whisky. The role helps us stand out within a highly concentrated market.
Why is wood such an important aspect of the Scotch-making process?
Many of the flavors and characteristics of whisky are picked up by the casks in which they are matured. Wood is also full of oil called vanillin which when drawn out of the cask by the spirit contributes to the strong flavor profiles.
What different types of wood do you use to make The Macallan’s barrels and how do they affect the Scotch?
We use American oak and European oak. The latter is the traditional wood used to make whisky and has a tighter grain and more porous structure as well as a high level of tannins which gives you dried fruit, spiced like cinnamon and nutmeg and even chocolate flavors. American oak gives the whisky a lighter color and characteristics of vanilla, honey, nuts and ginger.
We also have a Fine Oak line that uses bourbon barrels as part of the aging process which come from distilleries in Kentucky.
Where does The Macallan get its wood from?
With the European oak, the process from acorn to bottle starts in the oak forests of northern Spain because of the tannin-rich wood. The wood is hand-fashioned in the province of Cadiz, and the casks are hand-crafted and toasted by our Spanish cask suppliers in Jerez.
Our American oak is sawn and air-dried in Ohio, and then the raw staves are shipped to Jerez in Spain and made into casks.
The bourbon barrels originate in the woodlands of the eastern United States. They are charred in the cooperages of Kentucky and then seasoned with premium bourbon whiskey for up to eight years before we import them to Scotland.
How long does the cask making process take?
About five years from when we identify the Spanish oak trees in Spain to the time we are able to fill new spirits in a cask, and the American oak takes just as long. Both kinds are seasoned with dry Oloroso sherry for approximately eighteen months before being emptied and shipped to Scotland to be filled with whisky. About a 150 people are behind this process. The craft of making casks is carried out by a cooper, who is responsible in ensuring that they are fit for purpose and hold liquid.
At any given time, we mature close to 170,000 casks in Jerez.