In Scotland’s central belt, just outside Sterling, four million casks of whisky are currently maturing in huge warehouses that line nine miles of a private road network, known as Black Grange, Cambus.
We crawled past warehouse after warehouse at the speed limit of 5mph; I still had a hard time trying to keep count of all the buildings that looked more like airplane hangers than stores, either side of us. Behind these walls are the adolescent whiskies that will mature to become the Taliskers, Lagavulins, Obans and Singletons of my later years. We turned a corner and entered what looked like a theme park for whisky lovers. It’s referred to as the Barrel Park, where 7,500 casks await their next adventure. It may be called the Barrel Park, but don’t make the mistake of using the word ‘barrel’ when speaking with a whisky expert; they’ll quickly correct you by pointing out that whisky is aged in a wooden cask, not a barrel.
But I guess they can relax with the formalities when at home. This Cooperage at Cambus only opened in 2011, and was a consolidation of four other cooperages. The craft is still greatly respected in Scotland, having been practised there for centuries. In the 18th century, almost everything was transported in wooden casks—vegetables, fruit and cheese in cheaper casks and liquids such as beer and whisky in better made, water tight casks. Both distillers and blenders had their own coopers and numerous independent craftspeople operated all over Scotland. The UK had an obsession with sherry in the 18th and 19th century and ports such as Bristol and Glasgow were awash with big butt shipping casks. The sherry itself had little impact on the wood, as it was only filled for transport, but seeing as the Spanish didn’t want them back, the casks were very desirable to distillers for the rich, winey notes contained in the European oak.
Depsite the obsession with sherry there was never enough shipping casks to meet the needs of Scotch distillers. Local coopers filled the gap by importing mainly American oak from the Baltic region, as the ship building industry had already significantly depleted Canada’s resources. In the early 20th century, as sherry grew in stature, increasingly brand-aware producers began sending their product in bottles, not casks. The coopers and distillers looked to the bourbon counties of Kentucky America to fill the gap. The coopers’ unions in the USA were a force to be reckoned with, and to ensure continued employment for their members, managed to push through a law that meant bourbon casks could only ever be filled once. As a result, even today all bourbon must be matured in American oak barrels, usually three to six years and then disposed of.
Sure enough, brokers soon emerged, seeing an opportunity to help sell these second-hand casks to Scotch distillers, a cycle that has remained in place to this day. The second-hand casks are broken down into wooden staves in Kentucky and shipped to Scotland, where they are rebuilt into larger hogshead casks that can hold 250 litres (compared to their 200-litre former selves). This change in size is required to offset the impact of Scotland’s colder climate on the maturation process. A thirsty ex-bourbon cask’s first fill will usually be a single grain whisky, as they can absorb the strong vanilla flavours from the wood, are aged for a short five to 12-year period and are usually destined for blended whiskies. Once disgorged, the second fill onwards will be with single malt whisky, for eight to 20 years at a time. The amount of refills will depend on how active the cask is; this is judged by how much colour the wood gives to the spirit. The richer the colour, the more active the cask. When a cask becomes inactive after 35 years or so, it can be rejuvenated at the cooperage. The 36 coopers at Cambus rejuvenate between 480 to 500 inactive casks per shift.
I walked amongst them as they removed the top and bottom of the casks, scraped and flamed the inside wood to char it, before building it back up again and putting it back into circulation. The aim is for a cask to be rejuvenated two or three times so that it has the same lifetime as an oak tree (around 100 years). With this in mind, a cooper will probably never rejuvenate the same cask twice in their career. I walked through the Barrel Park just outside the cooperage alone, and soaked in the rich history. Each of these casks were awaiting their next fill, while the whisky they formerly nurtured might have been shared by the fireside, used as a toast to mark an occasion or mixed in a cocktail – anywhere around the world in recent years. If you’d like to become a cooper, there’s an apprenticeship scheme at Cambus that runs for four years. To apply visit diageo-careers.com
In January we will be hosting a tasting of malt, grain and blended Scotch Whiskies for our readers in London. Please follow us on Instagram for details of how you can win a place at the bar.