What’s the Difference? Scotch vs. Bourbon

by Keith Savage · 21 comments

Bourbon Flight

I had to restrain myself – many times – while writing my last post about the Jim Beam distillery. I kept veering off into technical definitions of Bourbon so I could lay them against equally technical descriptions of Scotch and thereby highlight the differences between the spiritual cousins. It would have derailed the post and been an injustice to Jim Beam.

But I realized I needed to write about this topic, especially since my aim in going to the Kentucky Bourbon Trail was to compare America’s spirit against Scotland’s and highlight the differences for the whisky fans among my readers.

I hope this will prove to be a useful reference for the rest of my series on the Kentucky Bourbon Trail. So here it is, a brief guide to the differences between Scotch and Bourbon gleaned from my visits to distilleries at home and abroad.


Whiskies are liquors made from cereal grains, which is a pretty large category. Barley, corn, oats, wheat, rye, sorghum, millet, and triticale all fit the bill. Both Scotch and Bourbon use water and yeast, but the primary difference between the two spirits is their choice of grains.

Bourbon is made with at least 51% corn, though many distilleries use up to 75% corn in their Bourbons. Corn imparts that Bourbon sweetness people seem to love or hate. The other 49% of the mash bill can be made of whatever grains the distillery wants to use, though rye, malted barley, and wheat usually make up the difference. Across the Kentucky Bourbon Trail, distilleries used a second grain, either wheat or rye, which they called the flavoring grain, to make up the second biggest percentage. In general, malted barley composed 10% of a mash bill to “round off the flavors” as some guides told me. Rye typically imparts a spicier, less sweet element to whiskey while wheat yields a sweet, inoffensive smoothness.

Scotch is made with malted barley, to which other whole grains may be added. Single malt whisky, arguably the most popular type of Scotch whisky, is made with 100% malted barley. Blended Scotch can have other grain spirits added to it, often referred to as neutral grain spirits, but there are still two separate distillations happening: one for the malt whisky and one for the neutral grain spirits. These two distillations are then blended together; there are no mash bills in Scotland. Malted barley yields smooth, complex flavors in the final product.


Both Scotch and Bourbon have some interesting laws surrounding the strengths of their spirits. I don’t know the backstories on how these proofs were chosen, but I’m willing to bet these were some of the most divisive topics between distillers and their respective governments. After all, the higher the proof the more alcohol in the bottle, and alcohol is truly what is being bought, sold, and taxed here.

Scotch cannot be distilled to more than 94.8% alcohol by volume, not that you could get a much higher ceiling. That said, in my experience, most Scottish distilleries are cutting their newmake spirit between 120 and 150 proof. On the other end, Scotch cannot be called Scotch once the ABV drops below 40% (80 proof). This is one of the parameters that makes aging Scotch for a very long time difficult. Alcohol evaporates every year and many distillers have to cut short maturation because a given cask is hovering at 40.1% ABV after a few decades in the warehouse.

Bourbon, on the other hand, cannot be distilled to more than 80% ABV (160 proof). Interestingly, there’s a unique proof law that states Bourbon cannot be entered into barrels at higher than 62.5% ABV (125 proof). Finally, like Scotch, Bourbon must be bottled at no lower than 40% ABV (80 proof).

Generally, the proofs don’t mean much for the flavor of the whiskies, though they are the primary data point for calculating speed to drunkenness and severity of hangover. Scottish distillers have a lot more freedom with their proofs, but distillers might tell you it doesn’t mean much for them. There are impurities in the spirit at too high and too low ABV. The heart cut, that sweet spot chosen by each master distiller, is where the purest flavors live.


The second most important difference between Scotch and Bourbon resides in how the two spirits are matured.

Scotch must mature in oak casks in Scotland for a minimum of three years. These oak casks must not exceed 700 liters and must age in excise warehouses. Furthermore, laws recently changed such that Scotch must also be bottled in Scotland. Previously, distillers could sell casks to buyers outside Scotland. This allowed buyers to continue aging the spirit in its cask after sale and potentially sell it again, later on, for heaps more profit.

Bourbon must mature in charred, new oak barrels, and age for at least two years.

On the face of it, these requirements might seem random, but temperature and wood play important roles in these laws. Kentucky experiences broad temperature fluctuations – hot summers, cold winters – and this has a huge impact on the “aging” of whiskey in barrels. As temperatures change, barrels contract and expand, releasing more of the angel’s share and speeding up the process of flavoring the spirit, whereby the wood absorbs and expels the liquor. Since they must use charred, new oak barrels, too, there are loads of flavors coming off the wood. You can have a nice Bourbon in a fraction of the time it takes to get a nice Scotch.


In Scotland, temperatures are consistently cool all year long. Rarely do they have heat waves or bone chilling cold. So the barrels work much more slowly on the whisky inside their staves. Additionally, Scottish distilleries primarily use oak barrels that have been used to age another alcoholic beverage previously, such as Bourbon, Sherry, Port, wines, beer, and Scotch. Used barrels have lost some of their original wood flavor and gained others, and distilleries in Scotland use barrels over and over again (sometimes as many as five times!). It takes longer to bring out the flavors in the wood with each successive use of the barrel.


This might seem obvious, but you can’t make whisky outside of Scotland and call it Scotch (though the Japanese have tried). Whisky can only be called Scotch if it follows the previous rules and is made and aged in Scotland. Other countries make whisky with the exact same ingredients and methods, but they are forced to use the much less prestigious term “malt whisky.”

Bourbon…well, now this is interesting. Many people believe Bourbon can only come from Kentucky. That is wrong. Bourbon must be made in the United States of America, but it can be made anywhere within the country (so long as all the other rules are followed). Bourbon’s name derives from Bourbon country in Kentucky, but the manufacture of Bourbon isn’t relegated to this region by law. In other words, you can drink Texas Bourbon or Wisconsin Bourbon and that would be legal and right.

The Bottom Line

Whew, that was a lot of minutiae. Does it make sense to you? Contradict what you’ve always known? Support it?

Knowing all this information, the best way to ferret out the differences between Scotch and Bourbon is really simple. Taste it. I think you’ll pick up on the differences pretty quick.


Glenn DuncanNo Gravatar September 18, 2016 at 11:53 PM

Bourbon must be aged a minimum of two years.

JohnNo Gravatar December 19, 2015 at 3:59 AM
Keith SavageNo Gravatar December 19, 2015 at 7:28 PM

I enjoy Bourbon every now and then, but this article is clearly a joke.

ThomasNo Gravatar June 11, 2015 at 10:29 PM

Great article! May be interesting to learn more about the process of drying the malted barley using heat (and smoke) from peat for scotch. Not all distilleries do it but most of them do. I find it interesting that much of the peat harvested from the earth into bricks (think fire starter logs in the US) is hundreds of years old and it is a limited resource. Well, there may be so much of it that we may run out in 3015, but I just don’t know. Peat forms naturally from the vegetation over time versus planting a corn, barley, wheat, or rye crop that yields annually.

Bourbon always has Corn and barley (the yeast catalyst in bourbon) and usually one flavoring grain: rye or wheat in the mash-bill.

Finally, it is worth noting that scotch needs to age longer in the barrel because it is typically cool year round in Scotland. In the states, we have a wider range of temps that allow the barrel to contract and expand with greater frequency and consequently grabbing the amazing flavors of the virgin white oak barrels.

Keith SavageNo Gravatar June 11, 2015 at 11:36 PM

Actually, peat harvested today is many, many thousands of years old. It is a finite resource.

Scotch needs to age longer in the barrel than other whiskies because distilleries almost always use barrels that have been used before (for aging Bourbon, sherry, or wine) and it takes longer to extract the remaining flavonoids in the wood. That said, many Bourbon distilleries like to perpetuate the myth of “over-aging” Bourbon. It’s ridiculous. Just try Elijah Craig 20+ year old and see what I mean. It’s amazing.

Gayla~No Gravatar August 25, 2013 at 3:36 PM

This was great. You’ve pretty much covered all of the bases and answered my questions. It makes sense that Scotch must be made in Scotland, but I had no idea about Bourbon being a US label. Not surprising that the US isn’t as strict in its regulation on the drink. I admire the areas that restrict the appellation, it definitely adds value and a uniqueness to a region and a product.

Jonny BlairNo Gravatar August 15, 2013 at 10:52 AM

First time to see this site and love it – the whole Scotch v Bourbon thing crops up again. One question for you – do you drink Irish Whiskey? Have you been to the Oldest Whiskey Distillery in the World? Have you been to Northern Ireland? Hoping you might have some stuff on Bushmills and Irish Whiskey! Best wishes, Jonny

Keith SavageNo Gravatar August 15, 2013 at 11:02 AM

Hi Jonny,

Sure, I drink Irish whiskey, but not all that often. I must say I’ve had some really excellent drams out of Ireland recently though, gold like Redbreast 15 and Connemara peated. I’ve yet to make it to Northern Ireland and the distilleries of Ireland, but believe me they’re on my list.

Jonny BlairNo Gravatar August 15, 2013 at 11:05 AM

Nice one Keith – I’m an Irish whiskey fan – the Bushmills Distillery in Northern Ireland does tours and has a bar at the end where they let you try a “tour only” whiskey. 16 year old malt I think. I’m from Northern Ireland originally and always prone to one as I travel round the world! Will keep checking your site for updates! Jonny

RebeccaNo Gravatar August 12, 2013 at 5:25 AM

haha thanks for this guide! now at least I can get my facts right when im talking about what im drinking. you have wrote it in such a way that I actually understand… cheers!

CharlesNo Gravatar July 22, 2013 at 2:57 PM

Wow! Consider me happily educated. I was never quite sure the difference between the two but have always enjoyed both on occasion. Thanks for enlightening me on the differences here. That three year minimum also explains a lot of things I’d heard but been unsure of. Thanks for the great post!

MichaelNo Gravatar July 22, 2013 at 6:07 AM

From the Loch Dhu website:

Loch Dhu, means “Black Lake” in Gaelic, it is an extraordinary single malt scotch. Only crafted for a few short years in the mid 1990s this amazing “black velvet” quickly acquired a cult following and unopened bottles are becoming increasingly difficult to find with prices rising fast. Loch Dhu was distilled in the Mannochmore distillery, which lies in the heart of Scotland’s “Speyside” region. There has been a distillery on this site going back to 1876. It takes its water from the Bardon Burn high up on Mannochmore hills.

The unique Loch Dhu taste and appearance was created by aging the whisky in special, double-charred oak casks. Charring the casks twice enhances Loch Dhu’s distinct black colour, and its smooth, slightly sweet flavour. Look for a slightly smoky nose with clean layered aromas of sweet malts and notes of ripe fruit and honey. The whisky has a dry, balanced and complex finish.

It does not say anything about E-150 or Caramel. It only mentions “double charred” oak barrels. However, to each his own. I found it rather exciting the first time I had it, the second time and ultimately the bottle. Only wish now I had hung onto it as it seems the “cult following” status and rarity of remaining bottle would have made it a good investment.

MichaelNo Gravatar July 16, 2013 at 11:37 AM

I thoroughly enjoyed this post. I am a fan of both Scotch Whisky and Bourbon Whiskey. I’ll have a wee bit o’ Irish Whiskey once in a while also but the former two are my favorites with Bourbon on top of them all. I did find it rather wrong of the Japanese to try to make a Scotch. Nope, that cannot happen. As for Bourbon made outside of Kentucky, not to sure on that. Those I have tried distilled outside of KY just do not have the flavor. I don’t know if it is the technique, the water, the location or whatever but as one who has had practically every Bourbon made in KY at one time or another, there is a difference from those made outside of KY. Maybe I am just being biased, who knows.

With respect to Scotch, I came across a wonderful dark single malt one day that immediately turned into my favorite. If you ever happen to see the name “Loch Dhu Black Whisky” I suggest you give it a go! It is definitely something to experience if you enjoy Scotch. It was a few years ago I found it in an Italian restaurant North of Detroit by about 23 miles or so. I never expected to find anything this good but there it was. I had no idea what it was all about so I read the label and had a few drams. It was love at first sip. http://www.loch-dhu.com/

Thank you for the article, it was a great read and informative. Thanks for your insight!

Regards, Michael

Keith SavageNo Gravatar July 16, 2013 at 8:19 PM

Kentucky is renowned for its water. They have lots of calcium in the water, which apparently aids in making soft water. Soft water is a distiller’s dream.

The Loch Dhu sounds interesting, though it’s very expensive. I’m curious to know how the whisky turns that color – it literally looks black. Perhaps aging in heavily-charred new oak barrels for a long time would do that, but I have a hard time imagining that tasting very good. I’ll keep my eyes peeled for it. Thanks for the recommendation.

Rod GrahamNo Gravatar July 18, 2013 at 11:23 AM

Loch Dhu (based on single malt from Mannochmore) isn’t produced any more, although there is another whisky, Cu Dhub, which is in the same style. The colour and flavour derives from the huge amount of E150 (aka Plain Caramel) added to the whisky.

Here are a couple of colourfully negative reviews:





Keith SavageNo Gravatar July 18, 2013 at 4:52 PM

Thanks Rod. Ouch…the Malt Madness Shit List.

Jim BowerCaNo Gravatar August 1, 2013 at 7:26 PM

Calcium (and magnesium/iron) make for hard water. Water with minerals usually has a “better” taste.

Keith SavageNo Gravatar August 1, 2013 at 9:12 PM

This is certainly true for drinking water, but distillers prefer softer water for whisky.

KenNo Gravatar July 16, 2013 at 7:28 AM

Great job of comparing and contrasting. Added to my reference list!

AdamNo Gravatar July 16, 2013 at 2:07 AM

And… what would you say are the major differences in flavor between Scotch and Bourbon? Obviously, there’s a wide variety. But in my experience they are also distinct.

Keith SavageNo Gravatar July 16, 2013 at 8:51 AM

Funny that I left off the taste part. I was so intent on the recipe and process. Getting into taste differences in a comment wouldn’t do the subject justice. Instead, I think I’ll use this as an excuse to write another post on the topic. In general however, Bourbon is sweet sweet sweet. Scotch is sweet, but generally more complex flavor-wise with additional savory, salty, and bitter notes.

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