The Real Difference Between Whiskey and Bourbon

Walk into any pub in the country and order a bourbon and coke, and the bartender won’t even look up. Ask the bloke beside you what actually makes it bourbon and not just whiskey, though, and you’ll probably get a shrug and something about Kentucky. He’d be half right at best.

Every bourbon is a whiskey, but not every whiskey is a bourbon. Bourbon is a particular style of American whiskey, and the name comes with a set of rules written into US law. Once you know them, the label on the bottle starts to make a lot more sense, and you’ll also know why no Aussie distillery can call its whisky bourbon, however good it is.

Whiskey first

Whiskey is a spirit distilled from fermented grain and aged in wooden barrels. Barley, corn, rye and wheat are the usual suspects, either on their own or mixed. Scotch, Irish, Japanese, Australian and American whiskeys all fall under that heading. What separates them is the grain, the barrels, how long it’s aged, and where it’s made, and most whisky-making countries have their own rules on top.

For the Scotch side of things, I’ve written a separate piece on the difference between single malt and blended whisky.

The rules that make it bourbon

Bourbon is defined in the US federal standards of identity for spirits. To carry the name, a whiskey has to meet every one of these:

The corn is where bourbon gets its sweeter, rounder taste compared with a Scotch made from malted barley. The new charred oak does the rest. A fresh barrel with a charred inside gives up colour and those vanilla and caramel flavours much faster than the second-hand barrels most Scotch distilleries use, which is why a young bourbon can still taste rich.

Those used bourbon barrels don’t go to waste either. Because American distillers can only use them once, a huge number end up in Scotland and elsewhere, including Australia, aging other whiskies.

Reading a bourbon label

Once you know the basic rules, a few other words on the label are worth understanding:

Bottled-in-bond is the interesting one. It goes back to the Bottled-in-Bond Act of 1897, when dodgy operators were colouring cheap spirit to pass it off as aged whiskey. It was one of America’s first consumer protection laws, and bonded bourbons are often some of the best value on the shelf.

Does bourbon have to come from Kentucky?

No. The law says the United States, not Kentucky. Kentucky makes most of the world’s bourbon and is home to the big names, but distilleries in plenty of other states make it too.

The US part is non-negotiable, though. In 1964, the US Congress formally declared bourbon a distinctive product of the United States, giving it the same kind of protection Scotch has.

Tennessee whiskey and rye

Jack Daniel’s is the obvious one. It isn’t sold as bourbon, and that’s a deliberate choice. Tennessee whiskey follows the same basic recipe as bourbon, starting with at least 51% corn, but it has to be made in Tennessee and goes through an extra step: the new spirit is filtered through maple charcoal before it goes into the barrel. Fans reckon that makes it smoother. Either way, it’s its own category.

American rye whiskey works the same as bourbon, except the mash bill has to be at least 51% rye instead of corn. That makes it drier and spicier. If you find bourbon a bit sweet, a rye is worth a go.

Whisky or whiskey?

Both are right. As a rule of thumb, Scotland, Canada, Japan and Australia spell it “whisky”, while Ireland and most American distilleries use “whiskey”. It’s tradition rather than law, though. Maker’s Mark, a Kentucky bourbon, spells it “whisky”, and so do the US regulations themselves.

Why Australia can’t make bourbon

When Australia signed its free trade agreement with the United States, the Australian Government formally agreed not to allow any product to be sold here as bourbon or Tennessee whiskey unless it was made in the US under American law.

That means an Australian distillery could follow the bourbon recipe to the letter, with 51% corn and new charred oak, and still not be allowed to put “bourbon” on the label. That’s why you’ll see Australian whiskies described as “bourbon-style” or “corn whisky” instead. Western Australia’s Great Southern Distilling makes the point well, as quoted by drinks writer Campbell Mattinson: if their Tiger Snake whisky were made in America, it would simply be called bourbon.

Think of it like Champagne. Plenty of places make great sparkling wine, but only one region gets to use the name.

Aussies and bourbon

Australians get through a lot of the stuff. In 2025, Australia was the third-biggest market for American spirits in the world, worth US$138 million, behind only the European Union and the UK. A big chunk of that is bourbon and Tennessee whiskey, and a big chunk of that gets mixed with cola at barbecues, footy grand finals and just about every 21st in the country.

The bottom of the glass

Bourbon is whiskey made in the US from at least 51% corn, aged in new charred oak, with nothing added except water. That recipe is what gives it the sweet, vanilla-heavy flavour that sets it apart from Scotch. Anything that doesn’t follow those rules can still be a great whiskey. It just isn’t bourbon.

Next time you’re at the bottle-o, turn the bottle around and read the label. You’ll be surprised how much it tells you.

Cheers.