Peated whiskey immediately conjures images of sipping a medicinal Islay malt beneath the shadow of a crumbling castle in the windswept moorlands of Scotland. But peat bogs are not a strictly Scottish or even European environment. While peat is prevalent across every continent, this fragrant earth has largely been absent from American whiskey. These days, however, local distilleries large and small are utilizing this potent and potentially polarizing ingredient.

Peat forms in waterlogged wetlands where, due to high acidity and lack of oxygen, plant matter doesn’t entirely decompose. This results in a compact, soil-like, carbon-rich substance. Traditionally, in some parts of the world, these wetlands have been drained so the peat can be cut, dried and burned for fuel.

Historically, peat’s inclusion in Scotch was a practical matter. Most of the old forests of Scotland had been felled by the time whiskey became a major industry there in the 19th century. Peat was necessary not just to fire the stills but to malt the barley as well. While the heat from peat fire warmed the malt to stop the germination process, its smoke would permeate the grain with the characteristic phenolic smells of peat. The strong flavor of peat, then, was originally a by-product of production necessities. According to Aeneas MacDonald’s classic book, Whisky, almost all single malt in Scotland was still peat malted as late as 1930, and local peat was a major concern for distillers. Today, only a fraction of Scotland’s distilleries peat their malt, but the flavor profile it imparts is so powerful that Scotch is still synonymous with peat in the minds of many.

Peat used at Brother Justus for its signature “cold peating” process.
Photo by Eliesa Johnson of The Restaurant Project, 2022.

Scottish Inspiration, American Ingenuity

The earthy and medicinal notes of peated spirits can be polarizing but, for those who love it, they can also be inspiring. This was certainly the case for the late Steve McCarthy, founder of Clear Creek Distillery in Portland, Oregon (now in Hood River, Oregon), who first tasted peated single malt on a trip to the British Isles. According to McCarthy’s head distiller Caitlin Bartlemay, he “returned home with a plan to make an Oregon single malt from top to bottom with Oregon peat, barley and oak.” The Oregon oak, surprisingly, proved the easiest to source. McCarthy had been using casks made from local Oregon oak (Quercus garryana) since the first barrels were filled in 1995. But the peat and barley was more of a challenge, so he settled on a mashbill of 100% peated Scottish barley from Port Ellen Maltsters on Islay, Scotland, which is what the distillery still uses nearly three decades later.

Balcones Distilling, a top seller of American single malt, began with a similar inspiration. “That’s where my own personal whiskey journey started, with Islay,” says Balcones head distiller Jared Himstedt. However, sourcing peated malt was a challenge in the early days. Balcones was using Golden Promise (a variety of barley used in older, classic Scotches) but its supplier, Simpsons, “wasn’t selling peated Golden Promise in their catalog,” remembers Himstedt. But Simpsons would custom-peat it if Balcones would take a whole malting floor. That would mean many thousands of gallons of wash, so the idea was put on hold until Balcones moved to its newer and much larger facility in 2016. Now, this peated Scottish barley is a part of Balcones’ yearly production.

Love of peat inspired other distillers not to make single malt but to put a smoky spin on America’s favorite whiskey: bourbon. “As a hobby distiller, my story of how we started to incorporate peat is that I was making the things that I enjoy,” remembers Jim Hough of Liberty Pole Spirits in Pennsylvania, “I’m a bourbon and rye guy, and I was making those, but my wife is just a huge Islay Scotch fan. She loves peated Scotches, so she started asking me to make something peated.” But peated malt was not cheap. Instead of trying to work around the cost of grain for a peated single malt, Hough “came up with the idea to just add some peated malt to a bourbon mash.”

Malt is often a component of bourbon and rye mashbills, providing not just sweet and bready notes but also crucial enzymes which help the fermentation process. Incorporating the peated malt was simple enough, but introducing peat to some American palates has been a bit more complicated. “Peated whiskies are very polarizing to an American whiskey audience. Half the people [who taste it] hate it, as they’re just not peat fans,” admits Hough. Fortunately “the other half find it life-changing.” Peated bourbon and rye, while not the best-selling of Liberty Pole’s whiskies, remain popular and occupy a “respectable niche” in their portfolio.

For other distillers, the journey to peated bourbon was less intentional. By 2011, Kings County Distillery in New York was already using peated Golden Promise for its single malt, but since the spirit was going into used barrels, its release seemed “far in the future,” according to Kings County founder Colin Spoelman. But one day, as they kept putting away bourbon alongside their single malt, they ran out of barley for the next mash. “The distiller on duty, Rob Easter, noticed we’d run out of Golden Promise for the regular bourbon, and he said, ‘I’m just going to make peated bourbon.’ And I thought that was a great idea.” It did indeed turn out to be a great idea. “It’s been a huge whiskey for us,” notes Spoelman, “our number-two most popular whiskey.”

The complex smokiness of peat can complement the sweet oak notes of whiskeys aged in new barrels. Many distilleries have begun to introduce peated bourbons and ryes, including those well outside of the craft world. Buffalo Trace recently released a peated bourbon as part of its Experimental Collection. This line of whiskeys includes everything from unique cask finishes to entry proof trials to new toasting techniques and now includes a whisky that substitutes peated malt for the usual barley.

Digging into Local Peat Sources

While many distillers are putting a uniquely American spin on peat, the peat itself is often of Scottish origin. Peatlands exist across the globe and cover almost 3% of the earth’s land area. But the extraction of peat is not always a simple process, so it is usually only practiced in areas with few other options. This was historically the case in Scotland and, while peat is no longer a necessity for daily life, the continued thirst for peated Scotch means it remains much easier to source peat from the U.K. than the States. For some American distillers, then, utilizing ready-made Scottish peated malt was an easy production decision, delivering practical benefits as well as a connection with a long tradition. Using peated Golden Promise has “always had an element of history, of tradition preservation,” recalls Balcones’ Himstedt.

The peat bog near Hood Canal, Washington, where Westland harvests its peat.

But a growing number of American distillers are choosing to detach from that tradition and instead connect with the local environment in a novel way. “Importing peat from a different region just didn’t line up with who Westland is and the company we want to be, which is very representative of the Pacific Northwest,” says Tyler Pederson, distillery manager for Westland Distillery in Seattle. So, off Westland went in search of local peat — which turned out to be surprisingly simple to find. “Honestly, it was almost too easy to identify a local peat bog that we could harvest from,” admits Pederson. “We just Googled ‘peat bog’ and it was right there on the map.”

Not all distilleries are so fortunate, as many of America’s peat bogs are protected or exist in fragile ecosystems. Texas distillery Balcones was able to find nearby sources of peat, but they were in areas that locals felt should be protected. Head distiller Himstedt remembers it was tough to walk away from but that they decided “to respect the environmental concerns and also respect that community.”

Finding an extractable source of peat is only the first hurdle. Next, it needs to find its way into the malt. Very few Scottish distilleries still use older, inefficient methods that actually depend on peat. But the demand for peated malt has never ceased, so many large malt houses have found ways to incorporate peat smoke into the kilning process, such as piping smoke into a malting drum. That commercial scale is what has allowed American distillers to easily import peated malt from Scotland. On the other hand, the specialized process has meant an added obstacle for those trying to incorporate American malt. “All of the historic knowledge of how to infuse peat smoke into grain is in Scotland,” said Tyler Pederson of Westland. But this challenge has led to ingenuity, as Westland has worked with maltsters eager to work out the problem, first pelletizing and then powderizing peat in an attempt to capture the unique flavors the distillery is pursuing.

Sugar Creek Malt Company in Lebanon, Indiana, has experimented with both new and decidedly old methods. “We have a Såinnhus, which is our Scandinavian-style smokehouse,” explains Sugar Creek’s Caleb Michalke. “We make traditional smoked malts, and we do the entire drying process with wood for that.” This Old World technique has produced some interesting malts but has proved difficult for peat. The Indiana and Illinois peat they use “is just not dense enough to put off a ton of heat,” laments Michalke. This has meant returning to a post-malting smoking process, which has still been popular with both brewers and distillers of bourbon and other unique whiskeys.

Brand-New Approaches

While many distillers have worked carefully with experienced maltsters, others are experimenting with the peat themselves. Andalusia Whiskey Co. in Blanco, Texas, has been custom-smoking their malt for years. They were recently  ranked in Whisky Advocate’s top 20 list for their Stryker Single Malt, which is distilled from grain smoked with oak, mesquite and applewood. Andalusia’s head distiller, Moose Allen, says the company has recently taken this same process and applied it to peat. Although it originally used Simpsons peated malt, Andalusia quickly moved to smoking its own grain, first with peat “logs” from Ireland and then with American peat prepared in a unique way. After acquiring loose peat from North Dakota, “I ended up having to make mud pies in loaf pans and just set them on top of the still and let them bake dry,” explains Allen. “I smoked grain with that and it was so successful I think we’ll move forward that way with the peating program.”

Inside the Andalusia Smoke Haus

Whether during or after malting, most distillers burn peat to activate its smoky and phenolic signature. Brother Justus Whiskey Company in Minnesota has taken a markedly different approach, using what the company terms “cold peat” in its “Aitkin County Process.” Founder Phil Steger says he wondered, when it comes to peated whiskey, “How much of that flavor is smoke and how much of it is peat?” Although most distillers believe smoking the peat is an essential step in the process, Phil believes “it destroys the identity of that piece of land. There is an identity in those plants, in that location, every plant that grew in that square foot, some part of it has been in the bog for ten thousand years — when wooly mammoths were walking the earth.” How does Brother Justus extract those qualities? Essentially by filtering already finished single malt through Minnesota peat, much like the charcoal of the Lincoln County process that inspired the name of their technique.

How the peat is treated and applied to the malt can have a huge impact on flavor. But an even bigger impact is rooted in the source. As partially decomposed organic matter, peat can be made of vastly different species of plants. Scotch connoisseurs have long known that different kinds of peat impart unique flavors to whiskey. These differences are brought about by the age of the bog, its proximity to the sea, and what kind of plants compose the peat itself: moss, former deciduous forest, meadow, or coniferous trees. Now, American maltsters are finding that variability both intriguing and challenging. Michalke describes the Indiana peat he uses as, “much looser and more fibrous. It’s definitely a different age than most Scottish or Irish peat.”

Alan Reed Bishop, who uses Sugar Creek Malt Company’s Indiana peated malt in Spirits of French Lick’s unique Whiskey Witch, says it gives “a fruity character as it comes off the still.” Matt Hofmann of Westland Distillery agrees the source of peat can dramatically affect the flavor of the whiskey. “If you look at the bog where this peat comes from, it is way different from Islay,” Hofmann notes. “It’s not just moss; it’s full of trees and wild cranberries and crab apples and all sorts of deciduous bog plants. What was in the bog that created this peat a long time ago we don’t really know, but it has made an impact on the flavor.” For his North Dakota peat, Moose Allen describes the flavor as, “porky, meaty and phenolic over iodine and road tar.”

The unique qualities of different peat sources should come as no surprise. Peat is more than dirt; it is thousands of years of growth and life, whole ecosystems over the span of entire epochs. Whether the sphagnum moss fields of Scotland, the boreal forests of Minnesota, the cranberry bogs of Washington, or the sedge-filled prairies of North Dakota, the history and flavor of place is preserved in the form of peat, right below the surface. And American distillers are only just beginning to dig.