The Role of Peat in Whisky Production: A Comprehensive Guide

A Laphroaig distillery employee works the peat bogs in the Inner Hebrides, Scotland (Jay West/Bottle Raiders)

Peat is one of those terms that pops up often in whisky conversations, especially when discussing scotch. But what exactly is peat, and how does it shape the flavor of the whisky you’re sipping? Let’s dive in and explore everything you need to know about peat, its role in scotch and how it affects the whisky’s taste.

What Is Peat?

Peat is essentially a type of soil that forms when organic material, like plants and moss, decays in waterlogged conditions. It’s a slow process, taking thousands of years to accumulate enough peat to be used in production. This organic material is rich in carbon and has been used in various industries for centuries, but in the world of whisky, it plays a crucial role in the flavor profile, primarily in Scotland.

How Is Peat Used in Whisky Production?

Peat comes into play in the malting process of whisky production. Here’s how it works:

1. Malting: Barley is soaked in water to start germination, sprouting the grains.
2. Kilning: Once germinated, the barley needs to be dried to stop further growth. And that’s where peat comes in. Peat is burned in the kiln, and the smoke from the fire infuses the barley with distinctive smoky, earthy aromas. These compounds, called phenols, are what give peated whisky its signature smokiness.

The longer the barley is exposed to the smoke, the more intense the peaty flavor will be.

What Flavors Does Peat Add to Whisky?Pea

The smokiness you get from peated whisky is tricky to explain and is far from one-dimensional. Peat adds layers of flavor. Here’s a quick breakdown of the most commonly cited flavors in peated whiskies:

• Smoky: This is the classic characteristic of peated whisky. It can range from subtle hints of smoke to a full-on campfire experience.
• Earthy: Think moss or a damp forest floor.
• Medicinal: Some whiskies have a distinct iodine or antiseptic taste.
• Seaweed/Maritime: Particularly common in whisky from coastal distilleries, like Old Pulteney, peat can bring out the taste of seaweed or salty sea air.

Each whisky’s peat profile is influenced by the peat’s origin, as different regions have different types of peat that impart unique flavors.

Does the Source of Peat Matter?

Yes! The location of the peat sourced can change the character of the whisky. This is often referred to as “peat terroir.” just like wine, the place where the peat comes from can influence the end product. For example:

• Islay Peat: Often made up of sphagnum moss and seaweed, Islay peat tends to produce whiskies with bold medicinal, salty and smoky characteristics.
• Highland Peat: Generally made from heather and wood, Highland peat tends to impart a sweeter, floral and less overpowering smoky profile.

Are All Scotch Whiskies Peated?

No, not all Scotch whiskies are peated. In fact, many whiskies, especially those from Speyside or the Lowlands, are unpeated. These regions are known for producing whiskies with a lighter, fruitier profile. On the other hand, Islay is famous for its heavily peated whiskies, which are rich in smoky and maritime notes.

How Do We Measure Peat in Whisky?

The level of peat in whisky is measured in phenols, specifically in parts per million (ppm). Here’s how different ppm ranges translate into flavor:

• Lightly Peated (1-10 ppm): Subtle smokiness, more of a gentle whiff than a punch.
• Moderately Peated (11-30 ppm): More noticeable, but still balanced with other flavors.
• Heavily Peated (30+ ppm): Intense smokiness, the kind that fills your nose with that familiar campfire aroma.

Some scotches fly high above this scale, aiming for incredibly intense peaty flavors. Islay’s Bruichladdich Distillery, for example, releases its Octomore series each year, with ppm levels reaching even north of 300.

Bruichladdich’s Octomore Series contains some of the most heavily peated scotch whiskies in existence. (Photo: Bruichladdich)

Other factors like fermentation, distillation, age and cask type can also affect how much smoke and peat flavor comes through, so ppm isn’t the only indicator of how smoky a whisky will taste.

Can You Adjust the Peat Flavor in Whisky?

Distilleries tweak how much peat gets into their whisky using a variety of methods:

• Kilning Time: The more time the barley spends near peat smoke, the stronger the flavor.
• Blending: Mixing peated whisky with unpeated whisky can create a more balanced flavor.
• Cask Maturation: The type of casks used can mellow the smoky notes, allowing other flavors to shine through.
• This allows distilleries to offer a range of peat levels, from light and subtle to bold and intense.

How Should You Taste Peated Whisky?

If you’re new to peated whisky, here are a few tips:

• Start with a Lightly Peated Whisky: Begin with something on the milder end of the scale before working your way up to the more heavily peated expressions.
• Cleanse Your Palate: Make sure your palate is neutral. A sip of water or a cracker can help cleanse your taste buds between tastings.
• Add Water: A splash of water can open up the whisky, softening the smoke and revealing hidden flavors.

For a complete guide to tasting whisky, click here.

Is Peat Use in Whisky Production Sustainable?

Peatlands are important ecosystems, and excessive harvesting of peat has raised environmental concerns. Peat bogs store carbon, and when disturbed, that carbon is released into the atmosphere, contributing to climate change. The whisky industry has taken steps toward more sustainable practices, from sourcing peat responsibly to exploring alternatives.

Conclusion

Peat is a key ingredient in many Scotch whiskies, giving them their signature smoky and earthy flavors. Whether you love or dislike peated whiskies, understanding peat’s role in the process can help you appreciate the complexity behind your favorite dram. From the subtle, lightly peated bottles to the bold, smoky expressions, peat offers a unique experience in every sip.