The Scottish whisky industry falls into five official whisky regions and one unofficial one. While there are smoky whiskies from other areas, Islay is the most popular for its big, bold, peaty flavors.
There is nothing like peated whisky. Think of a deep, smoky flavor – almost like a campfire. During the drying process of barley malt, peat fires produce compounds responsible for peated whisky’s unique taste. Rather than peat itself determining the smoke’s intensity and flavor, it is how long the malted barley stays exposed to the smoke.
Peat bogs cover much of Scotland. It can take 1,000 to 5,000 years for decayed vegetation to form these peat layers, several meters thick. Marshes grow about 1 mm each year. Therefore, a bog 3 meters thick could be around 3000 years old.
Peat comes from decomposing plant remains. It’s a combination of grasses, moss, and heather, waterlogged and starved of oxygen. That is the first step on the way to coal.
A peat bed comprises various layers, with the youngest & softest peat on top and the oldest & hardest at the bottom. In 10,000 years, this bottom layer may become coal! The highest-level layer, which is soft, goes for horticultural purposes. Even though a lot of the flavor is in the lower levels, the roots contribute the most.
The peat hills of Scotland were among the most readily available fuel sources early in the industry’s history. Boggy areas didn’t serve as functional drainage areas because water accumulated and caused moss, grass, and tree roots to decompose, creating peat. Although this history is essential, what makes peat so iconic is what the Scots do with it.
Distillers harvest peat, dry it and use it in the distillery kiln to dry and flavor malted barley. Distillers lay the malted barley in the kiln, between 15-18 inches deep on the floor. They then burn the peat below, causing the smoke to rise through the grain, drying it and enhancing the flavor. According to the atmospheric conditions, the flavoring process usually lasts 12 to 15 hours.
When the malted barley dries to about 15% moisture content, the peat phenols will no longer cling to it, so the remaining drying process is complete using coke at a higher temperature. After drying, the malt will contain around 5% moisture.
Whisky doesn’t just taste like burned peat. The water distilleries use flavors from peated whisky as well. Most distilleries use nearby water sources that contain peat. Distillers believe peat water contributes around 15% to whisky flavors.
The peat burns beneath the malted barley in a massive kiln to stop germination, producing thick smoke penetrating the grain. Traditionally, this step in the process defines the distinctive characteristics of peated Islay single malts such as:
Many Ardbeg’s whiskies hover between 50 and 55 ppm (phenol parts per million), which gives them a distinctive peatiness without coming across as overpowering; the flavor of the spirits and the barrels the distillers age the whisky in still shine through.
It’s possible to have different smoky flavors, for example, peat smoke, earthy smoke, and bonfire smoke. It depends on the process, the shape of the still, and the peat in the still.
Peat flavors vary from region to region based on time spent peating, One part per million (ppm), and maturation time. Peat can have various flavors, including soapy, sulphuric, medicinal, rich, smoky, aromatic, smooth, citrus, salty, nutty, diesel, and mossy. They stand out from other spirits with their broad spectrum of flavor notes.
Peated whisky has various phenols that affect its aromas and flavors.
Charred, smoky (noticeable in taste)
Charred, smoky (noticeable only in aroma)
Herbal, earthy peat, tar
Phenol (carbolic acid)
Medicinal, antiseptic, TCP
Peat defines Scottish Scotch. Even though the barley may have grown in an English field and the cask made with Italian oak, the peat gives the whisky its local flavor. A few other countries that use peat in their whisky-making process include:
Local mining is okay for those with their peat sources, as long as it’s environmentally safe, just as Mackmyra in Sweden and Lark Distillery in Tasmania do. Most times, countries without access to peat, such as Japan, import peated malt from Scotland. Peat from Islay, Orkney, and mainland Scotland exhibit apparent differences, so imagine the variety of characteristics peat from other regions such as Sweden, Australia, or the U.S. imparts to whiskies.
Drinks with a peaty Scotch base are rare. It’s all about striking a balance that makes scotch more accessible by allowing the base ingredient to shine.