Smoky Spirits 01: Peat, Phenols & the Truth About PPM
How smoky whisky gets its character and why numbers don’t tell the whole story.
Some people run from smoky whisky like it’s on fire. Others chase it like it’s the last campfire on earth. Whether you’re a smoke devotee or a hesitant sipper, one thing’s for sure: smoky spirits make a lasting impression. But what actually makes them smoky?
Spoiler: it’s not just "peat." In this lesson, we’re breaking down how smoke gets into whisky, the chemistry behind it, and why PPM is not the silver bullet people think it is.
In this lesson we’re going to talk about:
A Short (and Smoky) History of Peat in Whisky
How Whiskies Get Smoky
PPM: What It Is (and What It Isn’t)
Okay But What Are Phenols Exactly?
The Language of Smoke: Describing What Getting more Descriptive with “Smoky” Flavor
A Short (and Smoky) History of Peat in Whisky
Before smoke became a style, it was simply a necessity.
In the early days of whisky making, especially in Islay, Orkney, and other island communities, distillers didn’t have easy access to coal or firewood. What they did have in abundance was peat: spongy, decomposed plant matter that had piled up over millennia in their boggy landscapes.
When dried and burned, peat gave off a long, steady heat. It wasn’t clean-burning like coal, but it was accessible and cheap, perfect for heating homes and drying barley during malting. Early island distillers used peat fires to dry their malted barley not to create a specific flavor profile, but because it was the fuel they had on hand.
What they didn’t realize at the time was that the smoke from those peat fires was transforming the flavor of their whisky, leaving behind unmistakable aromas of brine, ash, tar, and earth.
Over time, that smoky character became a signature—especially for Islay whiskies like Laphroaig, Lagavulin, and Ardbeg. While many mainland distilleries moved to cleaner fuels and unpeated styles, the islands leaned in, building reputations on bold, phenolic drams that tasted like nothing else.
Today, using peat is no longer a necessity, it’s a choice. But for many distillers (and drinkers), it remains a powerful link to tradition, landscape, and identity.
How Whiskies Get Smoky
To make whisky, barley is soaked, sprouted, and then dried before it can be mashed and fermented. In peated whisky production, that drying process uses peat smoke—generated by burning blocks of compressed organic material from peat bogs.
Peat is essentially fossilized plant matter: a mix of moss, heather, grasses, and roots that’s accumulated and decomposed over thousands of years. When burned, it creates a rich, aromatic smoke. If that smoke is used to dry malted barley, it infuses the grain with smoky phenols—the compounds that carry through into the final spirit.
This process is part of malting, not distillation. That means the smoke is baked into the malt, becoming part of the whisky from the very beginning.