Whiskey prepared from malted barley that has been dried over a peat fire is called “peated.” The fire gets its distinctive and smoky scent from the burning of peat (a dense bog soil), which releases aromatic hydrocarbons. While Scotland, Ireland, and Japan are most well-known for producing peated whiskies, peat has been used in the malting process elsewhere. Whiskey’s peat flavor is determined by how long the malted barley was exposed to peat smoke and what kind of peat was burned in the kiln below.
What Is Peat?
In the wet, acidic environments of moors and bogs, partially decayed vegetation turns into the earthy material known as peat. Peat, a naturally abundant, dense fuel source, is still harvested from bogs, stacked, and dried for use as a fuel source today.
Commercially obtained peat is still burned for heat or electricity generation today via mechanized harvesting. Peat, despite its antiquity, is not a fossil fuel because it has not been fossilized; yet, burning it produces even more carbon dioxide than coal.
The Origin of the Peat is a Mystery
Peat is typically found in wet, marshy areas in the northern regions of Europe and North America. Almost all of the UK’s peatlands are located in rural Scotland, including the islands, the highlands, and the western mainland, but they may be found all over the world. It was one of the few readily available fuels in the area and was therefore utilized in the past as a means of creating fire:
- Whiskey malted barley drying in a kiln with a stack of peat.
- Whiskey distillery with malted barley on the floor of the malting chamber.
How is Peat Employed in Whiskey Production?
Peated whiskey is made by stacking briquettes of peat that have been chopped locally in a kiln. After being burned, the resulting heat and smoke travel up through the porous floor and a layer of malted barley.
The smokey, peaty aromas flood the room and seep into the grain. This is what distinguishes one distillery’s range of spirits from another by imparting a peaty, medicinal flavor to the whiskey. The damp barley is dried by the heat of the kiln below, thus stopping the germination process.
Peat was formerly burned to heat small pot stills and dry wet (malted) grain in the production of traditional Scottish and Irish whiskey. Only a handful of distilleries today employ peat to flavor and dry the grain for their peated whiskies. (Peat is not required at all whiskey distilleries.)
Among the few remaining distilleries, the Laphroaig distillery on Islay is notable for its continued use of the time-honored floor malting method. In addition, the barley undergoes a two-step procedure, beginning with a ‘peat’ treatment before being dried to bring out its signature peat flavor. That is to say, first the grain is cold-smoked, and then it is heated-dried.
Whiskey PPM Means What Exactly?
The amount of phenol left in the barley after being kiln dried is expressed in “Parts Per Million,” or “PPM.” The phenols in whiskey are responsible for its smoky or peaty flavor. The more parts per million (PPM), the more smokey and peaty the whiskey.
The PPM of whiskey can vary greatly. The distillery, the source water, and, of course, the presence or absence of peat in the kilning all play a role. The average proof of a whiskey is between 1 and 60 parts per million (PPM), but the Octomore 08.3 from Bruichladdich of Islay comes in at a whopping 309 PPM. Whiskey with a PPM of 30 or more can have a very strong smoke and peat character, whereas whiskey with a PPM of 10 or less is thought to possess a moderate level of peatiness.
Different whiskey distilleries have different recommended parts per million (PPM) levels. Some people may prefer a lower level for a more subtle flavor, while others could want a greater level for a stronger smoky taste. The amount of peat, type of peat, and kilning time/temperature all play a role in the final product’s peatiness.
Can You Explain the Distinction Between Smokey and Peaty Flavors?
The whiskey flavors of smoke and peat are sometimes misunderstood and mistaken for one another. There are primarily three ways in which smoky and peaty differ from one another.
Smoky VS. Peaty Flavors
The smell of smoke is pretty distinguishable, like that of a fireplace burning wood or coal, or even a just extinguished candle. Peatiness, on the other hand, is considerably more subdued and subtle on the nose, typically giving off woody or other organic plant aromas.
Smoky whiskey has a strong ashy flavor that hits your tongue like a puff of smoke from a cigar or cigarette. It has a dry, pleasant taste that is nearly like charcoal. Again, the onset of the earthy, woody, salty, and nuanced flavors that characterize peaty whiskey is much longer in coming.
Smokiness tends to leave a dry aftertaste, while peatiness typically lingers with a moist, herbal aftertaste. whiskey with a peaty character is sometimes cask-finished in oak to add a touch of sweetness to counteract the bitterness. This balance between bitter and sweet is what gives Islay single malts their distinctive flavor and helps explain why they are so popular.
I’m Curious About the Flavor of Peated Whiskey
The PPM, peat variety, and kilning method all play a role in imparting distinctive characteristics to peated whiskey. Earthy, woodsy, and herbal flavors are common examples of organic tasting characteristics. Others liken the therapeutic notes of THC or iodine to those of peaty whiskies. The complexity of flavor in peaty whiskies has led some to compare them to the “saltiness” of seaweed.
The story states that during the 1920s American prohibition, ‘bootleggers’ secretly imported Laphroaig. It is commonly held that whiskey could only be used for medicinal purposes due to its strong medicinal aroma and taste.
Which Distilleries Make Use of Peat?
Ardbeg, Caol Ila, Lagavulin, Laphroaig, and Bruichladdich are just a few of the well-known distilleries in operation today that regularly employ peat. Islay, like many of the other inner Hebridean islands, relies heavily on peat for its ecosystem.
Peat was used as a primary fuel source because it was one of the few available in the area. Peat is still used as the primary heat source for malting barley in these distilleries because the island has a limited natural gas supply even now. But Islay isn’t the only place you can get peat. Talisker Distillery on Skye and Allt-a-Bhainne Distillery in Speyside are only two examples of distilleries (islands and highlands) that use peat in their whiskies.
Some Irish Distilleries Even Use Peat in Their Whiskey Production
Connemara and Bushmills are the best-known examples. Both distilleries employ peat to give their whiskey a distinctive flavor, yet the two are easily distinguishable from one another. Peat is now also used by the modern Japanese whiskey producers Akkeshi and Nikka. Both used to import their peat, but now they harvest it from bogs in their respective regions. Distilleries in the Highlands and Speyside produce far less peated whiskey than those in the rest of Scotland. This is because malts produced on the east coast are often drier because of the availability of natural gas for kiln drying.