Whiskey (Bourbon)
The only major whiskey required to use a barrel once. New charred oak is the rule that defines bourbon, gives it its sweetness and colour, and incidentally supplies most of the world's Scotch and rum with somewhere to age.
Quick Facts
Flavour Profile
Primary Flavours
Tasting Notes
Warm and structured with notes of oak, caramel sweetness, vanilla, and gentle spice. Profile varies significantly depending on grain bill and ageing.
Recommended Brands
Budget Choice
Buffalo Trace: enough corn sweetness to mix with and enough backbone to still notice
Premium Choice
Woodford Reserve: rounder and more oak-led, which suits a stirred drink
Storage & Handling
Store upright in a cool, dark place away from direct sunlight. Reseal tightly after use to prevent oxidation and aroma loss.
Shelf Life
Indefinite when stored sealed and upright
Usage
50 to 60ml in an Old Fashioned, 45 to 50ml in a sour. It is the base of the Whiskey Sour, the Mint Julep and the Boulevardier, and the corn sweetness is what lets it carry sugar and bitters without turning thin.
The Rules
Bourbon is American whiskey made from a mash of at least 51% corn, distilled to no more than 160 proof, put into the barrel at no more than 125 proof, and bottled at 80 proof or above. Nothing may be added but water.
The barrel is the part that matters most: it must be new and it must be charred oak. That single requirement is doing most of the work in the glass, because a first-fill barrel gives up far more vanilla, caramel and colour than one that has held whiskey before.
Why the World Has Ex-Bourbon Casks
A barrel can only be new once. Because American law requires a fresh one for every batch of bourbon, distilleries are left with an enormous supply of barrels they may never use again.
Those casks go to Scotland, Ireland, the Caribbean and Japan, which is why so much Scotch, Irish whiskey and rum is aged in ex-bourbon wood. A rule written to define one category ended up shaping the flavour of several others, and a great deal of what people take to be the taste of Scotch is really the taste of a second-hand Kentucky barrel.
Not a Kentucky Rule
Nothing in the definition mentions Kentucky. Bourbon can be made anywhere in the United States, and increasingly is.
Kentucky's dominance is history and geology rather than law: established distilleries, limestone-filtered water low in iron, and hot summers that push whiskey in and out of the wood faster than a cooler climate would. Those are real advantages, but they are not requirements, and a bourbon from elsewhere is not a lesser category.
Where It Belongs
Anywhere the corn sweetness is useful. An Old Fashioned built on bourbon is rounder and broader than the same drink on rye, and a Whiskey Sour on bourbon needs less sugar than instinct suggests because the spirit is already bringing some.
Proof matters more than price in a mixed drink. Ice adds water, sugar adds body, and a 40% bourbon can arrive at the far end of a stir with very little left to say, where the same whiskey at 50% still holds its shape.
Pro Tip
A good cocktail whiskey should taste balanced on its own. Harshness only gets louder when mixed.
Top Tips
- Buy mid-proof rather than the cheapest. Around 45 to 50% gives a drink enough structure to survive dilution, where a 40% bottle goes soft under ice.
- Look for bottled-in-bond if you want a guarantee. It means four years minimum, one distillery, one season and exactly 50%, which is more information than most labels give.
- Keep the rare bottles out of cocktails. Sugar and bitters flatten the detail you paid for, and a good mid-priced bourbon makes the better Old Fashioned.
Possible Substitutions
- Dark rum (sweeter, less oak-driven)
- Aged tequila (different base, similar warmth)
Production Method
Produced by fermenting a grain mash, distilling the spirit, and ageing in wooden barrels. Regulations vary by region, influencing flavour and style.
History & Context
Whiskey has centuries-old roots across Europe and North America, evolving into a wide family of styles defined by local grain, climate, and tradition. It remains one of the most influential spirits in cocktail history.
Common Questions
What legally makes bourbon bourbon?
American-made, at least 51% corn in the mash, distilled to no more than 160 proof, barrelled at no more than 125, and aged in new charred oak with nothing added but water. The new barrel requirement is where most of the flavour comes from.
Bourbon versus whiskey?
Bourbon is one legally defined branch of the whiskey family, the way cognac is a branch of brandy. All bourbon is whiskey and most whiskey is not bourbon, because the corn proportion and the new charred barrel rule out almost everything else.
Does bourbon have to come from Kentucky?
No. Anywhere in the United States qualifies, and plenty of good bourbon is now made elsewhere. Kentucky dominates through history, established distilleries, limestone water and a climate that works whiskey hard, none of which appear in the definition.
What bourbon suits an Old Fashioned?
Mid-priced and mid-proof, around 45 to 50%. That is enough structure to carry sugar and bitters through a long stir without the drink going soft. Rare and expensive bottles lose their detail under sweetener and are better drunk neat.