After the barley is "malted" (sprouted), it has to be dried quickly in a kiln. If not, the sprouting will go too far, consuming the precious fermentable sugars and adding nasty tasting elements. In both Irish and Scotch whiskies, this is done by raking the malt out onto a large floor, under which a fire is burning to heat the floor. In Scotland, the smoke is allowed to enter the room with the malt as it dries. Some distilleries add peat (old, combustible, decayed heather, which covers much of Scotland's valleys and coastal lowlands) to the fire, which imparts a unique aroma and flavor. Smoke without peat has a dry, woody character useful for balancing the "sweetness" of the malt whiskey. Peaty smoke is oily-sweet. Some scotches take this to an extreme and are real peat-bombs, which a cynic might describe as gasoline or motor oil, intended for use by blenders as a flavor element. If the malt is more moderately peated, the peat-smoke will impart a unique flowery-oily smell. In Highland Park (from Orkney), the peat is younger, and will be more heather-flowery. On the west coast, and on Isla, the peat is older and deeper, further along in its eventual transformation to lignite (and eventually to coal), and will therefore have a more coal-tar or medicinal quality that you either love or hate. On Isla, peat affects the whiskey in another way, by way of the water. The water used in Isla whiskies runs through peat bogs, so it picks up quite a bit of that coal-tar flavor. So, if you drink a malt like Lagavilin, see if you can distinguish the difference between the peaty-water and the peat-smoke elements.