Islay whiskies are peaty because the island's distillers traditionally used locally cut peat to dry malted barley in their kilns, and many continue to do so. Burning peat produces phenolic compounds, primarily guaiacol and cresols, which are absorbed by the malt during the drying process and carried through distillation into the spirit. The specific character of Islay peat, formed from decomposed coastal vegetation, seaweed, and heather, produces the distinctive medicinal iodine, seaweed, and maritime smoke associated with Ardbeg, Laphroaig, and Lagavulin.