Ready for a walk on the wild side? A new whisky from Islay heavyweight Ardbeg has the usual intense peat and smoke notes, along with something else: weird and intriguing flavors created by wild yeast — by accident. Luckily, Ardbeg Fermutation, available to the distillery’s Committee members and whatever lucky Americans can track down a bottle, matured into something people will want to drink.
Though its creation wasn’t deliberate, Fermutation actually is a manifestation of something Bill Lumsden, head of distilling and whisky creation, had been noodling on for years, inspired by his taste in beer — or, rather, distaste for a particular beer. He hates Belgian lambics, yet could never stop trying them. “It was almost like a masochistic pleasure,” he says. Revisiting lambics repeatedly made him want to try replicating their fermentation process — which exposes wort to wild yeasts and microorganisms via open air tanks called coolships — for whisky.
The idea was outlandish. In Scotland, a typical whisky fermentation takes two to four days; otherwise, Lumsden explains, “it goes mad and goes sour.” Plus, Scottish distilleries overwhelmingly use one type of generic distiller’s yeast, a strain designed for maximum efficiency. “[Yeast is] treated as a commodity in the scotch industry, which I find hugely disappointing,” says Lumsden. Flavor creation, in scotch, tends to focus on the stills and casks — not yeast.
Contrast that with American whiskey makers, who boast of their yeast strains as integral to the character of the bourbon and rye. Distilleries like Four Roses, which famously uses five different yeasts, and Jim Beam, which showcases a fridge full of its proprietary yeast on distillery tours, have visibly emphasized the importance of their chosen fermentation agent. The founders of Wilderness Trail, Shane Heist and Pat Baker, run another business called Ferm Solutions, offering literally thousands of different types of yeast to clients.
But in Scotland, no such yeast diversity exists, and the idea of exposing a wort to uncontrollable wild yeasts is unthinkable. Yet that’s exactly what Lumsden did, when Ardbeg happened to suffer a major equipment failure that required it to either destroy what was in the fermentation tanks — or let it rip for nearly three weeks.
“I thought, ‘Wait a minute! We don’t want to be destroying this … Let’s embrace the serendipity of this and just see what happens,'” Lumsden recalls. He instructed the distillery staff to leave the tank lids open for 24 hours to capture whatever microbes were floating around in Islay’s maritime air. Then they were covered again —"just in case you get stray birds or the distillery cat” falling in, he says — while the microorganisms went to work.
Weeks later, the distillery was back up and running and the wild-fermented liquid, which Lumsden describes as “sharp, sour, zesty, leathery, all sorts of bizarre tastes,” went into the pot stills. What came out, though as peaty as ever, tasted nothing like Ardbeg’s typical new-make spirit. “The difference was black and white: This was a completely different creature,” Lumsden says.
Those stark differences come across in flavors like lemon sherbet and orange push pop, although 13 years in first-fill bourbon casks have smoothed out some of the sharper edges. “I would have preferred it to be a little bit wacky,” Lumsden confesses, adding that the original plan had been to launch the product two years ago and call it Ardbug — “as in microorganisms,” he says. “But given the fact that the world entered into a lockdown caused by microorganisms we thought that maybe might not be too sensitive.”
While Fermutation is the rare scotch that emphasizes yeast (Glenmorangie Allta, created by Lumsden using wild yeast obtained from the distillery’s barley fields, is another), it may soon have company. Some distilleries already diverge from the norm, like Loch Lomond, which does a five-day fermentation using three yeast strains, and newcomer Dornoch Distillery, whose fermentations run seven to 10 days using a variety of yeasts. Lumsden believes others are beginning to explore and experiment as well — as he is, at Glenmorangie, which opened a small-scale experimentation facility called The Lighthouse last year. It includes temperature-controlled fermentation tanks, a key tool when working with sensitive yeast strains that can die if the liquid gets too hot. Successful projects Lumsden carries out at The Lighthouse could be taken to full scale at either Glenmorangie or Ardbeg.
But already, the lessons gleaned from Fermutation’s happenstance creation have yielded bigger endeavors. “Having whetted my appetite for lambic-style fermentations by accident … I have now also done it by design,” Lumsden says. Look for those wild whiskies sometime down the road — if they work out.