Peated vs Unpeated Whisky: What's the Difference?

The difference comes down to how the barley is dried. For peated whisky, the malted barley is dried over a fire that burns peat, and the smoke leaves flavour compounds on the grain that carry through into the finished whisky. Unpeated whisky is dried with hot air instead, so it gets its flavour from the barley, the fermentation and the casks, without any smoke.

Most whisky in the world is unpeated. Peat is a style choice that some distilleries make, and it's strongest in a handful of places, most famously Islay.

I'll say upfront that I prefer non-smoky whisky, with lighter, sweeter notes. That's partly why this guide exists. If you're in the same position, it's worth understanding what peat actually does, because it makes it much easier to find the bottles you'll enjoy and avoid the ones you won't.

What smoky whisky actually tastes like

Smoky whisky can sound a lot more extreme than it actually tastes. The main thing you'll usually notice is something along the lines of burnt wood, ash or coal dust, but it tends to sit alongside the other flavours rather than completely overpowering them.

Depending on the whisky, the smoke can then take on different forms. Some have a medicinal character that can remind you of TCP or antiseptic cream, while others lean more towards burning rubber, tar, marker pens or even smoked ham and meat.

Underneath all of that, you still get the more familiar Scotch flavours such as vanilla, honey, fruit, malt and oak. The smoke is really just another layer sitting over the top, and how strong or unusual that layer feels depends heavily on the whisky.

That layer can also be much quieter than people expect. Tasting Highland Park 12, the peat was a very faint, earthy note running underneath the sweeter flavours, and even as someone who prefers non-smoky whisky, I actually quite liked it. With Johnnie Walker Black Label, the smoke only started to show on the nose after a little while, then came through more clearly on the palate.

How whisky gets peated

Peat is partly decayed plant matter, built up in wet ground over thousands of years. Dried and burned, it gives off a thick, aromatic smoke.

Whisky is made from malted barley, which is soaked so it starts to germinate and then dried to stop it growing. When that drying happens over a peat fire, compounds called phenols from the smoke stick to the grain. Those phenols are what you taste as smoke in the finished whisky.

The distillery controls how smoky the malt gets through how long it's exposed to the smoke. Some dry all of their barley over peat, some dry only part of it, and many use none at all.

What PPM means, and why it's only a rough guide

Peat levels are usually given in PPM, which stands for parts per million of phenols in the malted barley. It's the number people quote when they compare how smoky whiskies are.

The catch is that PPM is measured on the malt before it's distilled, not on the whisky in your glass. A lot of the phenols are lost along the way. Ardbeg, for example, uses malt peated to around 50 to 55ppm, but its new spirit has been measured at roughly a third to half of that. How the stills are run, how long the whisky spends in the cask and what sort of cask it is all change how much smoke you end up tasting. Older whiskies tend to taste less smoky than younger ones from the same distillery, because the smoke softens over time.

So a higher number usually means a smokier whisky, but two whiskies with similar figures can taste quite different. Treat PPM as a guide to the style rather than a precise measurement.

Peat levels at a glance

These are rough bands commonly used to describe peat levels, with examples. The figures are for the malt, and not every distillery publishes one.

Highland Park and Johnnie Walker Black Label don't fit neatly into a band, because only part of the malt that goes into them is peated. Both taste lightly smoky.

What people often get wrong about peat

That peated means Islay, and Islay means peated. Islay is the best-known home of smoky whisky, but it isn't the only one, and not everything made there is smoky. Talisker on Skye, Highland Park on Orkney, Springbank in Campbeltown and Benromach on Speyside all use peat. Meanwhile Bunnahabhain and Bruichladdich both make unpeated Islay whisky.

That the PPM tells you exactly how smoky it will taste. As above, the number is measured before distillation, and plenty of the smoke is lost or softened after that.

That all smoke comes from peat. Bourbon casks are charred on the inside, and whisky aged in them can pick up toasty, charred or slightly smoky notes without any peat involved. Sherry casks can give a dark, rich character that some people read as smoky too.

That all peated whisky tastes the same. The smoke varies a lot by place and by distillery. The heavily peated whiskies from Islay's south coast tend to be medicinal and maritime. Orkney's peat is lighter and more heathery. Mainland peated whiskies often have a drier, earthier kind of smoke.

That a well-known brand tells you whether it's peated. Some famous names cover both styles. Bruichladdich makes unpeated whisky and also the heavily peated Port Charlotte and Octomore. Bunnahabhain has peated releases alongside its unpeated core range. And Johnnie Walker varies from label to label, as our guide to whether Johnnie Walker is peated explains.

How to tell from the label

Labels rarely give a PPM figure, so you usually have to read the clues:

• Words like peated, smoky, smoke or peat are the clearest sign. Distilleries that make a peated version of an unpeated whisky usually say so on the front.
• The expression name matters more than the distillery. Check the specific bottle, especially from distilleries that make both styles.
• The region is a hint, not a rule. An Islay single malt is more likely to be smoky, but not certain.
• Check before you buy. We've answered this for Glenmorangie, Aberlour, Balvenie, Bunnahabhain and Johnnie Walker.

Which should you try?

If you already know you don't like smoke, stick with unpeated whisky. There's a huge amount of choice, and our guide to the best non-peated whisky brands is a good place to start.

If you're curious but a bit wary, start with something where the smoke stays in the background. Our guide to lightly peated whisky runs from the gentlest bottles up to the point where Islay smoke really starts to show, and it says clearly which ones we've tasted.