What Is Peated Whisky?

Peated whisky gets its smoky character from drying malted barley over burning peat during the malting process.

Peated whisky owes its smoky, sometimes medicinal or bonfire-like character to one step in production: how the malted barley is dried.

Where the smoke comes from

After barley is malted (soaked and allowed to partially germinate), it needs to be dried to stop germination at the right point. Traditionally, this drying happened over a kiln fire. In regions with peat bogs — most famously Islay in Scotland — peat (partially decomposed plant material cut from bogs) was burned as fuel. The smoke from burning peat clings to the grain, and those smoky compounds (phenols) carry all the way through fermentation, distillation and into the final spirit.

Measuring smokiness: PPM

Peat intensity is often quoted in phenol parts per million (PPM), measured in the malted barley before distillation. Lightly peated whisky might sit in the single digits, while heavily peated styles can reach 40, 50 or higher. It's a useful rough guide, but PPM in the malt doesn't translate directly to PPM (or perceived smokiness) in the finished spirit — plenty of other production choices affect how that smoke actually reads in the glass.

Not just a Scottish thing

While peated whisky is most associated with Scotland (particularly Islay), it isn't exclusive to it — distillers elsewhere, including some New Zealand producers, have experimented with peated or lightly peated releases, sometimes importing peated malt to do so, since New Zealand doesn't have the same large-scale peat industry as Scotland.