Scotch is distilled from fermented grain mash and made in Scotland, but the simplicity ends there. First mentioned in the Exchequer Rolls of Scotland in the late 15th century, Scotch is divided into five distinct categories today: single malt, single grain, blended malt, blended grain, and blended Scotch whisky. Scotch whisky is known for its precision and caliber of product identity, with a minimum aging requirement of 3 years in oak casks, specific fermentation regulations, regional, and other naming protections. Characteristics are distinct by region and distillery, ranging from smoky, deeply complex with apple, nutmeg, and vanilla in Speyside; bold flavors, heather, and dried fruit in the Highlands, Floral tones, toffee, and cinnamon in the Lowlands, and unique notes of brine, wet dog or wet wool, sea wood, and salt in other regions.