Bourbon and Scotch tasted side by side

The rules that make them different

Bourbon must be made in the United States from a mash of at least 51% corn. It is distilled to no more than 80% ABV and goes into new charred oak containers at no more than 62.5% ABV. No colouring or flavouring may be added. Straight bourbon must age at least two years.

Scotch must be made in Scotland and matured at least three years in oak casks there. Scotch malt whisky is made only from malted barley in pot stills. Scotch grain whisky uses other cereals in column stills. Most Scotch casks are second hand. Many of them are ex-bourbon barrels shipped across the Atlantic. Our guide to ex-bourbon, sherry and wine casks explains why.

So the two spirits are linked by the barrel. Bourbon gets the new, fiercely active oak first. Scotch often gets the same barrel afterwards, with much of that first rush already spent.

Set up a fair comparison

Pick an unpeated single malt Scotch matured mainly in ex-bourbon casks and a standard bourbon. Try to match strength within a few points, around 40 to 46%. If one is much stronger, its heat will mislead you.

• Pour 15 ml of each into identical tulip shaped glasses.
• Have still water at room temperature and plain crackers to reset between sips.
• Nose the Scotch first. Bourbon's sweetness can swamp a delicate malt.
• Taste with water on hand. Add a few drops to each after the first sip.

Keep the pours small and the evening slow. Two 15 ml pours tasted with attention teach you more than two large pegs.

What the grain gives you

Corn gives bourbon a rounded sweetness. Many tasters describe sweetcorn, caramel and a soft, almost buttery body. Most bourbon mash bills also include rye or wheat. A high rye bourbon shows more pepper and spice. A wheated bourbon tastes softer and breadier.

Malted barley gives Scotch malt whisky cereal, biscuit and malt loaf notes, often with orchard fruit from fermentation and distillation. It is drier and more textured than corn. If you know brewing, the malt in your glass has the same roots as the base malt in a pale ale. Our guide to grains in whisky goes further.

What the cask gives you

New charred oak hits bourbon hard. Expect vanilla, toffee, toasted coconut, baking spice and sometimes a dry, woody grip. The char layer also filters and adds a light smoky sweetness. Bourbon picks up deep amber colour in just a few years.

A refill ex-bourbon cask gives Scotch a gentler version of the same family: vanilla, honey and light coconut, but with the spirit's own fruit and cereal still clearly in front. In a side by side, you can often taste the bourbon in the Scotch, as a quiet echo of the cask's first life.

What the climate gives you

Kentucky summers are hot and winters cold. Warehouses swing widely in temperature, so spirit moves in and out of the wood often and matures quickly. Scottish warehouses stay cool and steady, so maturation is slow and long.

India sits closer to Kentucky than to Scotland here, which is why Indian single malts can taste rich and oak led at a young age. A three way tasting of bourbon, Scotch and an Indian single malt makes the climate effect easy to see.

Mistakes that spoil the comparison

A side by side only works if the conditions are equal. The usual slips:

• Uneven strength. A 50% bourbon against a 40% Scotch turns the test into a heat contest. Add water to the stronger one until they feel similar.
• Uneven pours. A bigger pour smells stronger. Measure both.
• Different glasses. A tumbler and a tulip glass present aroma very differently.
• Peat in the Scotch. Smoke changes everything. Save peated malt for another night.
• Knowing which is which. Expectations shape perception. Ask someone to pour blind if you can.

Reading the result

After the first round, write one line for each whisky on nose, palate and finish. Then answer three questions. Which tastes sweeter and is that grain or cask? Which shows more fruit? Which finish is longer and drier?

Most people find bourbon sweeter, richer and more oak driven. Scotch tends to be lighter, fruitier and more cereal led. The interesting part is the overlap: the vanilla in both, the shared oak spice. Separating what came from the grain and what came from the barrel is a real skill. It is the same skill a blender or a quality panel uses every day. It improves fast with guided practice.

As always: water between sips, small pours and nobody drives home after.

Your first step

Buy a miniature or a single bar pour of each whisky rather than two full bottles. Set up the tasting above with a friend, compare notes and see where you agree. Then add a peated Scotch next time to find out how smoke changes the picture.

Common questions

What is the main difference between bourbon and Scotch?

Bourbon is made in the US from at least 51% corn and matured in new charred oak. Scotch is made in Scotland, often from malted barley. It is usually matured in used casks.

Why does bourbon taste sweeter than Scotch?

Corn gives a rounder sweetness than malted barley. New charred oak adds strong vanilla and caramel notes.

Should I taste bourbon or Scotch first?

Nose and taste an unpeated Scotch first, since bourbon's sweetness and oak can overwhelm a lighter malt.