"What's the difference between bourbon and whisky?" The short answer: bourbon is a type of whisky. Just as an apple is a type of fruit, bourbon is American whiskey that meets a specific set of rules.
This guide explains what makes a bourbon, and how it differs from Scotch and Japanese whisky in four areas: grain, casks, ageing and flavour.
How bourbon fits into the whisky family
Whisky is the umbrella term for spirits made by mashing, fermenting and distilling grains such as barley, corn or rye, then ageing the spirit in wooden casks. Each country or region has its own rules:
- Scotch whisky: made in Scotland
- Irish whiskey: made in Ireland
- Japanese whisky: made in Japan
- American whiskey: made in the United States
- Bourbon: American whiskey that meets requirements such as a corn-dominant mash
- Tennessee whiskey: made in Tennessee and charcoal-filtered before ageing
So bourbon is a category within American whiskey, which is itself a category within whisky.
What legally makes a bourbon
Bourbon is defined by US federal regulations:
| Requirement | Rule |
|---|---|
| Origin | Made in the United States |
| Grain | At least 51% corn |
| Distillation | No higher than 160 proof (80% ABV) |
| Casks | New, charred oak containers |
| Barrel entry | No higher than 125 proof (62.5%) |
| Bottling | At least 80 proof (40%) |
Notably, there is no minimum ageing period for plain bourbon. Whiskey aged at least two years and meeting further conditions can be labelled "straight bourbon," and if it is aged less than four years, the age must be stated on the label.
Bourbon vs Scotch vs Japanese whisky
| Bourbon | Scotch | Japanese | |
|---|---|---|---|
| Origin | USA | Scotland | Japan |
| Main grains | Corn (51%+) | Malted barley (malt) and other cereals (grain) | Malt (required) and other grains |
| Casks | New charred oak only | Oak casks up to 700L; used casks allowed | Wooden casks up to 700L; used casks allowed |
| Minimum ageing | None (2 years for straight) | 3 years | 3 years |
| Type of rule | Federal law | UK law (Scotch Whisky Regulations) | Industry standard (2021) |
The Japanese whisky standard was introduced in 2021 by the Japan Spirits & Liqueurs Makers Association as a voluntary industry standard. It requires mashing, fermentation and distillation at a distillery in Japan, at least three years' ageing in Japan in wooden casks of up to 700 litres, and bottling in Japan at no less than 40% ABV.
1. Grain
Bourbon is all about corn, which gives it a soft, rounded sweetness. Adding rye makes it spicier; adding wheat makes it mellower. Scotch single malt, by contrast, is made only from malted barley, with flavours centred on malt and fruit developed during maturation.
2. Casks
The biggest difference is the cask. Bourbon must be aged in new barrels charred on the inside. Fresh wood gives up plenty of flavour, producing vanilla and caramel notes and a deep amber colour.
Scotch and Japanese whisky frequently use second-hand casks — for example ex-bourbon barrels or casks that once held sherry. They give less wood flavour than new oak, letting the character of the spirit and the cask's previous contents shine through.
3. Ageing
Scotch and Japanese whisky must be aged for at least three years. Bourbon has no minimum, but because new charred oak works quickly, even young bourbon picks up plenty of colour and aroma.
4. Flavour
- Bourbon: sweet and toasty — vanilla, caramel and toasted oak; rarely smoky
- Scotch: wide-ranging, from elegant and fruity to intensely smoky from peat
- Japanese: often delicate and balanced, frequently with an elegant, floral nose
Classic bourbons to try
| Whiskey | Character |
|---|---|
| Jim Beam | Said to be the world's best-selling bourbon; light and clean |
| Maker's Mark | Uses wheat instead of rye for a soft sweetness; famous red wax seal |
| Four Roses | A blend of ten recipes; floral and light |
| Buffalo Trace | Smooth, with rich vanilla and brown sugar |
| Wild Turkey 8 | Eight years old at 50.5% ABV; bold and spicy |
Jack Daniel's is made much like a bourbon, but it is a Tennessee whiskey, filtered through sugar-maple charcoal before ageing. See Jack Daniel's vs Jim Beam for details.
How to drink bourbon
- Highball: soda water lifts bourbon's sweet aromas. In Japan the whisky highball is the everyday way to drink whisky with food.
- On the rocks: as the ice melts, vanilla and caramel slowly open up.
- Cocktails: bourbon is the base of classics such as the Old Fashioned and the Manhattan.
A side-by-side tasting
The best way to understand the "new oak sweetness" of bourbon is to taste it next to a Scotch or Japanese whisky. Try a bourbon alongside Glenmorangie The Original — a Scotch aged ten years in ex-bourbon casks — and Japan's Yamazaki. The rich sweetness of bourbon and the lighter fruit of the Scotch and Japanese malts will stand out clearly.
Explore more in our guides to American whiskey, Scotch whisky and Japanese whisky.
Summary
Bourbon is a type of whisky: made in the USA from at least 51% corn and aged in new, charred oak. Its biggest difference from Scotch and Japanese whisky is that it uses only new casks, which give it its sweet, toasty vanilla-and-caramel character. Knowing the rules makes a side-by-side tasting all the more rewarding.