We are proud to have been part of an article about Wild Yeast published in the excellent publication Spirits & Distilling. The article was written by Courtney Iseman and it can be read in full here. It is behind a paywall but Courtney has kindly agreed to us publishing an extract which you can read below. If you are looking for more interesting articles signing up for a subscription is a good option - plenty of detailed articles to dig into for the keen whisky drinker!
Here's the extract:
On Britain’s Isle of Man, Manx Whisky took a less scientific approach to blazing their fermentation trail.
“We never set out to be a hyper-traditional distillery,” says cofounder Magnus Grinneback. “We ended up being one because we wanted to be local. If you make a whiskey on the Isle of Man, it should be truly from the Isle of Man, so we do everything here.”
Their barley grows locally, they malt it there, and they produce and mature their whiskey there on the island. They started out fermenting with commercial yeast, but “given the importance of fermentation for flavor,” Grinneback says, “we thought, ‘Let’s just try ambient yeast just to see if we can imprint even more local flavors.’”
To do it, the Manx team simply lets their wort sit outside in open buckets, allowing whatever is around to settle in.
“If you really want to capture yeast that is ambient,” Grinneback says, “keep it away from the distillery because there you have commercial strains being airborne.” (It’s also crucial, he says, to keep your spontaneous and controlled fermentations separate—don’t let those wild strains get near your standard fermentor.)
Once they find a bucket they’re happy with, they use it for fermentation. Grinneback says he doesn’t know exactly what they get in the culture, but he assumes it’s a mixture of Saccharomyces cerevisiae, Brettanomyces, and lactic-acid-producing bacteria, among other things.
The flavor impact on the final spirit is funky—not dominant, but evident. It’s also complex, typically featuring barnyard-like notes, clean fruit flavors, and a desirable sort of sharpness.
“There are a lot of acids coming through, and I don’t know yet how that will impact the formation of esters during maturation,” Grinneback says, referring to a particular three-year-old cask, still aging, filled with a distillate whose mash was 100 percent wild-fermented.
Manx has produced other whiskeys with 15 percent wild-fermented mash, with the other 85 percent fermented by commercial yeast. That helps them with quality control, dialing in the characteristics they know they want in their whiskey. In terms of true repeatability, though, Grinneback warns against being too strict with spontaneous fermentation.
“We don’t strive for consistency,” he says. “If you strive for consistency, this would be a nightmare. We like that every batch is different. The difference is the point.”
From “Spirits of the Wild: Embracing Ambient Yeast” by Courtney Iseman, Spirits & Distilling, 28 September 2026. Read the full article here.