Introduction to American Single Malt Whiskey
More than a dozen whiskey-filled oak barrels sit on racks inside Ironton Distillery’s production facility in Denver. Most of it won’t be ready to drink for a while — it needs to age for two years — but when it is, this whiskey will be bottled and labeled as “American single malt.”
Colorado distillers are raising a toast to this new standard of identity for domestic whiskey, one that formally defines what ingredients can be used and how American single malt should be made. Instituted in December by the federal alcohol regulators, the designation joins vaunted labels like bourbon, rye and Irish Whiskey. This is the first time since 1968 that the Alcohol and Tobacco Tax and Trade Bureau has added a new one.
Background and History
While U.S. distilleries have been making single malt spirits for a long time, local whiskey producers believe the designation will allow them to better compete with powerhouses like Scotland and Japan. They are also confident that Colorado can take the lead in popularizing American single malt, thanks to the state’s strong beer heritage, which has cultivated a generation of distillers familiar with using its base ingredient, one that is frequently grown here as well.
“Colorado was and is at the forefront of craft beer in the country. We have a lot of people like me, who were brewers, who understand malt and who started distilling and making malt whiskey,” said Craig Engelhorn, co-founder and master distiller at Spirit Hound Distillers in Lyons. “Just like we were pioneers in the ’90s with craft beer, we’re pioneers now with malt whiskey.”
Creating a Category
The TTB defines American single malt whiskey as a beverage made from 100% malted barley that is mashed, distilled and matured in the U.S.
It must be aged in oak barrels that are a maximum of 700 liters (185 gallons) and bottled at least 40% alcohol by volume. While the spirit is required to be distilled entirely at one distillery, the definition leaves room for companies to either make it in-house or source it from another producer.
The parameters were largely informed by whiskey producers, who spent the nine years lobbying regulators. The movement started in 2016, when Steve Hawley, then working at Seattle’s Westland Distillery, convened with eight other spirit makers at a Binny’s Beverage Depot in Chicago. The group’s objective: To find consensus about what makes American single malt whiskeys distinct.
A bottle of Ironton Distillery’s Colorado Straight Single Malt Whiskey at Ironton Distillery in Denver on April 2, 2025. (Photo by Helen H. Richardson/The Denver Post)
Colorado’s Role
Malted barley is the primary ingredient used to make beer and the majority of whiskeys, and many local distillers transitioned to the spirits industry after cutting their chops at breweries.
That means local drinkers have access to some of the best single malt whiskeys in the country, said Spirit Hound’s Englehorn, who helped develop the original recipe for Dale’s Pale Ale in the early 2000s while he was a brewer at Oskar Blues.
Head distiller Laura Walters works at Ironton Distillery in Denver on April 2, 2025. (Photo by Helen H. Richardson/The Denver Post)
Spirit Hound sells six different single malts, including one called Colorado Honey, which is finished in barrels used to store local honey. It was awarded the title of American Single Malt Whiskey of the Year at the 2024 London Spirits Competition.
Flavor and Creativity
What most excites Ironton head distiller Laura Walters is the opportunity for creativity and innovation. The single malt definition mandates that distillers use 100% malted barley, but it doesn’t specify what kind or how it is roasted, which creates room for experimentation.
Distillery dog Ludo, a golden retriever, lies in the sunshine next to oak barrels with aging whiskey at Ironton Distillery in Denver on April 2, 2025. (Photo by Helen H. Richardson/The Denver Post)
For example, her flagship American Straight Malt Whiskey features 60% specialty malts roasted to various levels, drawing out different sugars and flavors. But a recipe Walters developed for Colorado State University athletics featured a different ratio of base malts and specialty malts, which created an entirely new flavor profile.
Conclusion
The introduction of American single malt whiskey is an exciting development for whiskey enthusiasts and the spirits industry as a whole. With its unique flavor profile and the opportunity for creativity and innovation, it is likely to become a popular choice among whiskey drinkers. As the industry continues to evolve, it will be interesting to see how American single malt whiskey develops and how it compares to other types of whiskey.
FAQs
Q: What is American single malt whiskey?
A: American single malt whiskey is a type of whiskey made from 100% malted barley that is mashed, distilled, and matured in the U.S.
Q: How is American single malt whiskey different from other types of whiskey?
A: American single malt whiskey is made from 100% malted barley, whereas other types of whiskey may be made from a combination of grains.
Q: What is the aging process for American single malt whiskey?
A: American single malt whiskey must be aged in oak barrels that are a maximum of 700 liters (185 gallons) and bottled at least 40% alcohol by volume.
Q: Can American single malt whiskey be made by any distillery?
A: Yes, any distillery in the U.S. can make American single malt whiskey, as long as it meets the definition and parameters set by the TTB.
Q: How can I try American single malt whiskey?
A: You can try American single malt whiskey by visiting a local distillery or by purchasing it at a liquor store. It is also recommended to try different types of American single malt whiskey to find the one that you enjoy the most.
