Scotch vs Bourbon vs American Single Malt Whisky
– A Whisky Guide –
What makes them different, why they taste the way they do, and what happens when Colorado’s legendary microbrew heritage starts turning it’s attention from beer to whisky.
Origins & Geography
Three spirits shaped by where they’re made – and one that rewrites the rules
Every great whisky is a product of its place. The grain that grows there. The water that flows there. The climate that ages it. Scotch and Bourbon developed their distinct characters not just through recipe and craft, but through the very geography that surrounds them. Why is Scotch often peated? Why is Bourbon made with corn? The answers are largely influenced by what the people had to work with in their particular environment. And now, officially a category of it’s own, American Single Malt adds a third dimension – the freedom to make great whisky anywhere in America, and let the local environment shape what it becomes.
Barrel Selection
New oak, old oak, or the distiller’s choice
The barrel is not just a container – it is an ingredient. And the most fundamental difference between Scotch and Bourbon is whether that barrel has been used before. Bourbon, by law since 1938, must be aged in charred, new American Oak. Historians often speculate that lobbying from the powerful timber industry during the Great Depression may well have influenced the 1938 ruling. Interestingly, that requirement allowed American oak barrels to be available and Scottish distillers became fairly reliant on using these second-hand casks. Now…American Single Malt, as a new category since 2025, is the first American whisky category to give distillers a choice.
Think of it like tea bags. A fresh barrel makes a strong, bold brew from the first pour. A refilled barrel gives more subtly over a longer steeping time — the result is layered in ways a fresh barrel never could be. American Single Malt is the first American whisky category that lets you choose which cup you want to make.
Barrel selection for Scotch vs Bourbon vs American Single Malt Whisky
Refilled Casks – The Used Tea Bag
Scotch primarily uses second-hand barrels – ex-Bourbon, ex-sherry, ex-wine. The wood has already given up its strongest flavors. What remains is subtle and complex: gentle sweetness, dried fruit, extraordinary nuance built slowly over years. The even climate means these barrels can work their magic slowly over a decade or more.
New Charred Oak – The Fresh Tea Bag
By law, Bourbon must use new, charred American oak – a rule dating back to 1938. That fresh char layer contains caramelized sugars and vanillin that the whisky absorbs powerfully. Even young Bourbons carry pronounced vanilla and caramel. The trade-off: age too long and the oak can overpower everything else.
New or Refilled – The Distiller’s Choice
This is the defining freedom of the category. The TTB rules allow new charred, new uncharred, or used oak barrels – meaning an American Single Malt distiller can pursue the boldness of Bourbon, the subtlety of Scotch, or something entirely their own. The barrel becomes a creative decision, not a legal obligation.
The Grain Bill
Barley, corn, and why the grain changes everything
Before a drop of spirit is distilled, the grain bill determines almost everything about the whisky’s character. Scotch and Bourbon start from fundamentally different raw materials – and that difference truly defines them. American Single Malt follows Scotch in its use of barley, but brings a dimension to that grain that neither Scotland nor Kentucky can claim.
Grain used for Scotch vs Bourbon vs American Single Malt Whisky
| Characteristic | Scotch Single Malt | Bourbon | American Single Malt |
|---|---|---|---|
| Primary grain | 100% malted barley | Minimum 51% corn | 100% malted barley – like Scotch, sourced anywhere |
| Grain character | Gentle, receptive – absorbs its environment readily | Bold and assertive – corn’s natural sweetness holds its own against fresh oak | Gentle like Scotch barley – but local terroir shapes what it absorbs. Colorado barley carries a natural chocolate profile unique to this altitude. |
| Mouthfeel | Lighter, drier, more delicate | Fuller-bodied, rounder, richer | Varies by distillery – can lean either direction depending on barrel and water |
| Typical notes | Malt, dried fruit, heather, peat, vanilla, nuts | Caramel, vanilla, toasted oak, baking spices | Unlimited – no two ASM distilleries taste the same. That is the point. |
| Barrel rules | Typically refilled – ex-Bourbon or ex-sherry casks | New charred American oak – required by law | New or used, charred or uncharred – distiller’s choice |
| Geographic rule | Scotland only | United States – primarily Kentucky – but this is not required | United States – anywhere, which is the whole point |
| Best served | Neat or with a drop of still water in a Glencairn | Neat, on the rocks, or in classic cocktails | Taste it first and let it tell you |
Scotch’s exclusive use of malted barley – grain that has been allowed to partially germinate before drying – produces natural enzymes that convert starches to sugars. But the deeper truth about barley is its character as a grain: it is gentle and receptive. Where corn is bold and assertive, carrying its own powerful sweetness that needs the barrel’s harmony to balance it, barley listens to its environment. It absorbs the influence of water, wood, and climate readily – which is precisely why the Scottish Highlands, Islay, and Speyside can produce such dramatically different whiskies from the same grain. Every variable leaves a mark.
That sensitivity is also why barrel choice matters so much for barley-based whisky. A brand new, heavily charred barrel is a dominating flavor. For a bold grain like corn, that produces the caramel and spice harmony Bourbon is famous for. For barley, a fresh barrel can simply overwhelm the grain’s quieter character. A refilled cask, by contrast, has already given its most dominating flavors away. What remains is subtler and supportive of the grain, not competing with it.
Colorado barley adds one more layer to this. Grown at high altitude in Colorado’s unique soil and climate, it carries a naturally chocolatey profile that Scottish barley does not. That character is worth protecting. It is part of why barrel choice is not just a technical decision for us – it is a creative one.
A Third Way
The Rise of American Single Malt Whisky
For decades, the Scotch vs Bourbon debate had only two sides. American distillers were quietly making extraordinary single malt whisky – 100% malted barley, pot still distilled, patiently aged – but without a legal home to call their own. On retail shelves they were lumped in with Scotch, or Bourbon, or whatever the owner decided. On bar menus they hid in the “other” category. The category existed in practice long before it existed in law.
That changed on January 19, 2025, when the U.S. Alcohol and Tobacco Tax and Trade Bureau (TTB) officially designated American Single Malt Whiskey as its own protected category – the first new American whiskey classification in over 52 years. The ruling was the result of nearly a decade of advocacy by the American Single Malt Whiskey Commission and its nearly 100 member distilleries, who had long argued that what they were making deserved to stand on its own terms.
The parallel most often drawn is to Japanese whisky – a category that took years for consumers to understand, then became one of the most sought-after spirits in the world. American Single Malt is at the beginning of that same arc. And the timing could not be better for the distilleries, like ours, who were building the category before anyone had a name for it.
How American Single Malt Whisky is different vs Scotch vs Bourbon
To be called American Single Malt Whisk(e)y, a spirit must be:
Distilled from 100% malted barley
Mashed, distilled and aged entirely in the United States
Distilled at a single distillery
Aged in new or used oak barrels – charred or uncharred
Bottled at no less than 80 proof
No requirement that barley be grown in the U.S. – imported barley is fully permitted
TTB Final Rule, effective January 19, 2025
The barrel freedom that changes everything.
Before January 2025, American whisky law required new oak barrels for anything labeled as a malt whisky. If you used a refilled barrel – the kind Scotland has used for centuries to make Highland Scotch – in America, your whisky legally had to be called something far less appealing: “whisky distilled from malt mash.” Not exactly a label that sells itself, but one that we ourselves were using.
We believed refilled ex-Bourbon casks were the right barrel for certain of our Malt whisky expressions. Here is why: barley is a gentler grain than corn, and Colorado barley has a naturally chocolatey character that is genuinely worth celebrating. Refilled oak gives it the room to do that. So we made it that way, labeled it correctly under the old rules, and hoped for the laws to change.
The TTB ruling didn’t change how we make our Single Malt. It just finally gave it the name it always deserved.
Today our Colorado Single Malt Whisky is exactly what it was always meant to be – an American Single Malt aged in refilled ex-Bourbon casks, shaped by Colorado barley, Minturn water, and Rocky Mountain air. The rules finally caught up with the whisky.
The Regions of Scotland
Scotland produces whisky in six distinct regions – each shaped by its own geography, climate, and tradition. Click any region to explore its character and how it connects to what we make in Colorado.
Select a region on the map to explore its flavour profile and distilleries.
Highlands
The most geographically diverse region in Scotland – stretching from Perthshire in the south to the far north coast. No single Highland style exists, but the region is broadly known for fuller-bodied, rounder, more complex whiskies than the Lowlands.
Glenmorangie, Dalmore, Oban, Balblair, Clynelish, GlenDronach, Ben Nevis, Old Pulteney
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Speyside
A sub-region of the Highlands so distinctive it earned its own classification. The River Spey flows through it, and more distilleries operate here than anywhere else in Scotland. Speyside made its reputation in the 19th century and remains the benchmark for approachable, elegant single malt.
The Macallan, Glenfiddich, The Glenlivet, Aberlour, Balvenie, Glenfarclas, Cardhu, Craigellachie
Islay
A small island off the west coast of Scotland that produces whisky of extraordinary intensity. Islay’s modern whiskies are the most consistent with their predecessors – retaining the heavy peat character that defined them from the start. Islay is where peat smoke is not just a flavour note but a statement of identity.
Laphroaig, Ardbeg, Lagavulin, Bowmore, Bruichladdich, Bunnahabhain, Caol Ila, Kilchoman
Islands
The Islands are not an official Scotch whisky region – they are technically part of the Highlands – but they are discussed separately because their character is so distinctive. Skye, Orkney, Arran, Mull, and Jura each produce whiskies shaped by their island geography: sea air, coastal peat, and maritime influence.
Talisker (Skye), Highland Park (Orkney), Arran, Tobermory (Mull), Jura, Ledaig
Highland Park from Orkney and Talisker from Skye are among the most beloved island whiskies – bold enough to satisfy peat lovers, complex enough to intrigue those who prefer something more nuanced. If you enjoy our Peated Malt, these are the natural next step into Scottish whisky.
Campbeltown
Campbeltown was once home to over 30 distilleries – the whisky capital of the world in the 19th century. Today just three remain: Springbank, Glengyle, and Glen Scotia. A region defined as much by its history as its character.
Springbank, Glengyle (Kilkerran), Glen Scotia
Springbank is one of the most respected distilleries in Scotland – independently owned, floor malted, and producing three distinct expressions in one facility. It is a reminder that small, independent, and obsessively focused can produce extraordinary whisky. Sound familiar?
Lowlands
The Lowlands produce the lightest, most delicate Scotch whiskies – traditionally triple-distilled, unpeated, and gentle. Often described as an aperitif whisky. The region has far fewer distilleries than its reputation warrants, but what it produces is genuinely distinctive.
Auchentoshan, Glenkinchie, Bladnoch, Ailsa Bay
If someone tells you they find Scotch too intense or too smoky, a Lowland expression is usually where to point them. Auchentoshan is approachable, floral, and genuinely lovely. It is also a useful reminder that whisky does not have to shout to be worth listening to.
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