There are essentially two breeds of single malt Scotch whiskey. Yes, there are experts would scream and stomp all over such a statement as an oversimplification, but let’s save such highly focused nitpicking for the snooty types and keep it basic.
Scotland’s Scotch production differs between the country’s mainland and the Island of Islay. The isle is small and isolated with a population that never gets much bigger than 4,000. Historically, the people of lonely, boggy Islay would build with wood and burn dug up chunks of thick peat moss for heat. Islay is lousy with peat and trees can be precious on a rocky island. So, essentially, the people of Islay (Islayans? No.) made their homes from trees and burned the ground.
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When it came time to make Scotch, Islay put the moss to work again. After barley (Scotch’s first ingredient) is soaked in tanks, it’s moved to a drying room. There the wet barley sits at room temperature while it’s malting. Once the barley sprouts little green shoots and the natural starches becomes sugars, it’s scooped out of the drying room. That natural sugar will transform to alcohol during cooking.
On the mainland, those drying rooms can be left alone or heated slightly — electrically these days. On sea-tossed Islay, the drying rooms had to be heated consistently to maintain a standard malting temperature. Distillers burned peat to create that warmth and ended up with smoked barley during malting. When you cook that peat dried barley, you end up with an earthy, smokey Scotch – while the whiskey made farther south without peat moss fires is often lighter and sweeter.
The most famous of the smokey Scotches include Laphroaig, Highland Park and Talister. Each is an acquired taste as the drinker is ingesting notes of soil and heavy smoke with each sip of whiskey.
But, how smokey does Scotch get? And, what is considered the smokiest Scotch. To be scientific and get beyond mere taste, there is a way to quantify smokiness. Peat amounts in Scotch are counted in chemicals call Phenols and rated in Parts per Million (PPM). If we use that scale, a popular Scotch like Laphroaig rates about 50, depending on aging and other factors. That’s a solid, average number for Phenols in PPM.
The PPM scale says the peatiest (and, therefore, smokiest) Scotch whiskey is Octomore from Bruichladdich with a Smokey the Bear-terrifying 169 PPM – more than three times smokier (as it looks ridiculous to write “Phenolicier”) than an average consumer Islay Scotch.
I tried a few sips at the London Athenaeum Hotel London Whiskey Bar and can attest that it’s a Scotch a man need to brace for and stand up to if he’s going to get through a glass, rocks or neat.