All bourbon is whiskey, but not all whiskey is bourbon. Bourbon is one legally defined style of American whiskey, with rules about where it is made, what goes in the mash and what kind of barrel it ages in. “Whiskey” is the wider family that also holds Scotch, Irish, Japanese, rye and Tennessee whiskey. Once you know the handful of rules below, a label tells you most of what is in the bottle.

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TL;DR

  • Bourbon is a type of whiskey. It has to be made in the United States, with a mash of at least 51% corn, and aged in new charred oak.
  • Other whiskies, such as Scotch and Irish, can use used barrels and different grains, which usually gives a lighter, more restrained style.
  • Expect bourbon to taste sweeter, with vanilla, caramel and oak. Rye is spicier and drier, and Scotch can range from fruity to smoky.
  • “Whisky” and “whiskey” are spellings tied to region, not quality. Scotland, Canada and Japan use the first, the US and Ireland the second.
  • Jack Daniel’s is a Tennessee whiskey, not a bourbon, because of an extra charcoal step.

Table of Contents

The short answer: a category and a sub-category

Think of whiskey as a category and bourbon as a sub-category, the same way sparkling wine contains Champagne. Under US federal rules, whisky (or whiskey) is a spirit distilled from a fermented mash of grain, stored in oak and bottled at no less than 40% ABV, with a specific exception for corn whisky, which need not be stored in oak. Bourbon takes that broad definition and tightens it.

That is why the question “bourbon or whiskey?” is a little like asking “Champagne or wine?”. You are not choosing between two opposites. You are choosing between the whole family and one particular member with a clear flavour signature.

The rules that make a whiskey a bourbon

The legal definition sits in US federal regulation. 27 CFR 5.143 says bourbon must be made from a fermented mash of not less than 51% corn, distilled at 160° proof or less, stored in charred new oak barrels at 125° proof or less, and bottled at not less than 80° proof (40% ABV). No colouring, flavouring or other spirits may be added.

Here is the same thing in plain terms:

Rule What it means Why you notice it
Made in the United States Bourbon is an American category 95% of the world’s bourbon supply comes from Kentucky, though it can be made elsewhere in the US
At least 51% corn in the mash Corn dominates the grain bill, often with rye or malted barley and wheat Sweetness and a fuller body
Distilled to no more than 80% ABV Keeps flavour in the spirit rather than stripping it out A richer, grainier base
Enters the barrel at no more than 62.5% ABV (125 proof) Limits strength before ageing Affects how the wood interacts with the spirit
Aged in new, charred oak The barrel cannot have held anything before Vanilla, caramel and toasted oak notes
Bottled at 40% ABV or higher A floor on strength Nothing watered below a standard drinking strength
Nothing added except water No colouring or flavouring Colour and flavour come from the process

The Oxford Companion to Spirits & Cocktails gives the same ABV limits in percentage terms and notes that new oak now generally means an unused barrel made from American oak. Food & Wine also points out that bourbon producers cannot add artificial colouring or flavours, so the colour in your glass is the barrel’s work.

You may have heard that bourbon must come from Kentucky. It does not. Kentucky is the heartland, but the legal requirement is the United States as a whole.

The rules that make a whiskey a bourbon

Why the barrel changes everything

If you remember one rule, make it the barrel. The Oxford Companion says the new charred oak requirement is unique to the US and does more than anything else to set bourbon, along with rye and Tennessee whiskies, apart from whisky made elsewhere. Charring caramelises the sugars in the wood, and the charcoal acts as a natural filter that removes some of the less desirable compounds from the spirit.

The chemistry explains the taste. According to The Chemistry of Bourbon from the American Institute of Chemical Engineers, ageing breaks down the cellulose and hemicellulose in the wood, releasing sugars. It also extracts tannins, which bring astringency and mouthfeel, and degrades lignin into compounds including vanillin, the source of vanilla flavour.

The same article explains why the barrel must be new: the compounds drawn from the wood are not replaced, so a second use would give lower concentrations and lower quality. Scotch and Irish whiskies, by contrast, may be aged in used barrels, often ex-bourbon ones.

That is the quiet connection between the two styles. Many Scotch and other whiskies spend their lives in casks that once held bourbon. For a look at how that plays out in an Australian bottle, we stock the Hobart Whisky American Oak Ex-Bourbon single malt at 55.7%, a good example of a bourbon barrel shaping a non-bourbon whisky.

How bourbon compares with the other whiskies

Bourbon v Scotch

Scotch is whisky made in Scotland. The Scotch Whisky Regulations 2009 reserve the term for spirit distilled and matured in Scotland for at least three years. Most Scotch uses malted barley rather than corn, and used casks are common, so the wood tends to be a supporting voice rather than the lead. The result runs from light, floral and fruity to rich and sherried or smoky, depending on the region and distillery.

Bourbon is generally rounder and sweeter, with more obvious vanilla, caramel and oak. Food & Wine notes that Scotch may use caramel colouring to keep batches consistent, while bourbon may not. If you like honeyed warmth, start with bourbon. If you like complexity that moves between orchard fruit, malt and smoke, start with Scotch. Our Scotch whisky collection is a good place to browse regions side by side.

Bourbon v Irish whiskey

Irish whiskey is protected under the Irish Whiskey Act 1980, which sets a three-year minimum maturation. It is often aged in used casks, which tends to give a lighter, softer profile than bourbon’s new-oak punch. Both are spelled “whiskey”, which causes plenty of the confusion behind this search.

Bourbon v rye

This is the closest comparison, because the production is nearly identical. As Bon Appétit explains, where bourbon needs at least 51% corn, rye needs at least 51% rye. Both must go into new charred oak. Neither has a legal minimum age for the basic label, though most ryes are aged at least two years.

The flavour difference comes from the grain. Rye tends to taste drier and spicier, while bourbon leans sweeter and fuller. Whisky writer Lew Bryson, quoted by Bon Appétit, links rye’s clove and spice notes to ferulic acid in the grain, which becomes a compound called 4-vinyl guaiacol with the right yeast.

In the US, the 51% minimum applies. Canada is different: Eater notes that Canadian regulations do not set a minimum rye percentage. If you want to go deeper, our guides cover rye versus bourbon and the 51% rule and a full flavour comparison of bourbon and rye.

Bourbon v rye

Bourbon v Tennessee whiskey

Jack Daniel’s is the question everyone asks. According to the brand’s own FAQ, it is a Tennessee Whiskey, not a bourbon. The distillate is dripped through ten feet of packed sugar maple charcoal before going into new charred oak barrels, and that charcoal mellowing step is what makes it Tennessee whiskey. The rest of the recipe sits close to bourbon, which is why the two are often grouped together.

Bourbon v Japanese whisky

Japanese whisky follows a Scotch-influenced approach. Under voluntary labelling standards from the Japan Spirits and Liqueurs Makers Association, effective 1 April 2021, a whisky carrying the Japanese label must be fermented, distilled and matured in Japan, aged at least three years and bottled at 40% ABV or higher. It is a different tradition from bourbon, with its own flavour language, and you can explore it in our Japanese whisky collection.

Whisky or whiskey: does the spelling matter?

The spelling follows geography rather than quality. Business Insider reports that the US and Ireland write “whiskey”, while Scotland, Canada and Japan write “whisky”, a split that began with small differences between Gaelic dialects in Ireland and Scotland. Over time each region’s spelling became entrenched, and each developed its own styles.

In Australia you will see both. Local distillers and retailers commonly use “whisky” for Australian and Scotch bottles and “whiskey” for American and Irish ones. A quick rule when reading a label:

  • “Whiskey” on an American bottle usually signals bourbon, rye, Tennessee or another US style.
  • “Whisky” usually signals Scotland, Japan, Canada or Australia.
  • The spelling alone cannot tell you the style. Look for the words “bourbon”, “rye” or “Tennessee” on the label.

If you want to work through labels with a collector’s eye, our guide to bourbon legal definitions, labels and collector tips is a useful next step.

What to expect in the glass

Taste is where the rules become practical. These are general tendencies, not guarantees, since every distillery and cask differs.

  • Bourbon: sweet and rich, with vanilla, caramel and oak. The corn-heavy mash and new charred barrels drive this profile.
  • Rye: drier and spicier, with pepper and clove notes from the grain.
  • Scotch: wide range, from delicate and fruity to smoky and sherried. Used casks keep the wood in the background.
  • Irish: typically lighter and softer, helped by used-cask maturation.
  • Japanese: shaped by its own labelling standard and a precise, balanced style.

As for colour, ageing is what darkens whisky. Wikipedia’s overview of whisky maturation lists six processes in the cask that shape colour and flavour: extraction, evaporation, oxidation, concentration, filtration and colouration. So a darker whisky is often an older or more wood-influenced one, though bourbon rules mean the colour must come from the barrel rather than additives.

Our view: read the label, then trust your palate

We sell whisky for a living, and the question we hear most is whether bourbon is “real” whiskey. It is, and it is one of the most clearly defined styles in the world. That clarity is a gift to buyers. A bottle that says bourbon has already told you about the corn, the new oak and the absence of additives.

Our approach is to put that information in front of you. Every product page on our site carries batch, ABV and cask details, because those numbers explain why one bottle tastes so different from the next. A cask strength bourbon and a used-cask Scotch are different experiences, and we think you should be able to see why before you buy.

If you are starting out, we suggest tasting across styles rather than committing to one. Try a bourbon for sweetness, a rye for spice and a Scotch for range. If the bottle you want is not on our shelves, we can help with personalised sourcing for hard-to-find releases.

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How to choose your first bottle

Match the bottle to the moment, not the label alone.

  1. Start with flavour. Sweet, vanilla and caramel points to bourbon. Spicy and dry points to rye. Fruity, malty or smoky points to Scotch.
  2. Check the ABV. Bourbon must be bottled at 40% or higher, but many bottles sit well above that. A higher ABV tastes bolder and takes a drop of water well.
  3. Look for the cask detail. New charred oak means bourbon territory. Ex-bourbon casks in a Scotch or Australian whisky mean you will still taste vanilla, but in a gentler voice.
  4. Think about use. For an old fashioned or a highball, a straightforward bourbon or rye works well. For slow sipping, look at older or cask strength releases.
  5. Consider gifting. If the recipient is new to whisky, a bourbon is often a friendly entry point because of its sweetness.

If you are comparing styles from different regions, our overview of the difference between whisky varieties and our breakdown of bourbon versus whiskey versus Scotch give you more to work from.

Find your bottle at Uisuki

When you are ready to taste the differences yourself, we stock premium whisky from Scotland, Japan, Australia and the USA, including rare and hard-to-find bottles. Browse our American whiskey collection for bourbon, rye and Tennessee styles, or look at Australian whisky to see how local distillers use ex-bourbon barrels.

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We ship locally and internationally, and you can ask us to source a bottle you cannot find elsewhere. Start at uisuki.com.au and pick the style that matches your palate.

FAQ

Is bourbon the same as whiskey?

Bourbon is a type of whiskey, but whiskey is not always bourbon. Bourbon must be made in the United States from at least 51% corn and aged in new charred oak barrels, as set out in US federal regulation. Scotch, Irish, Japanese and rye whiskies follow different rules.

What are the five rules of bourbon?

A widely quoted summary, reported by CNBC from Maker’s Mark COO Rob Samuels, runs like this. It is made in the US, aged in new charred oak, and mashed from at least 51% corn. It enters the barrel at no more than 125 proof and the bottle at no less than 80 proof. Nothing is added except water, and only to reduce proof when needed.

Is Jack Daniel’s a whiskey or a bourbon?

Jack Daniel’s is a whiskey, specifically a Tennessee whiskey. The brand says on its official FAQ page that it is not a bourbon, because the spirit is mellowed through sugar maple charcoal before it goes into new charred oak barrels.

What is rye whiskey?

Rye whiskey is made from a mash of at least 51% rye grain in the US, as Eater explains. It tends to taste drier and spicier than bourbon, which is sweeter and fuller because of its corn base.

Is whiskey a dark liquor?

Most aged whiskey is amber to deep brown, because the colour comes from time in the cask. Younger or lightly aged spirits can be paler. Bourbon cannot have colouring added, so its shade reflects the barrel, which is why the label and age are better guides than colour alone.

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