A hardwood tree genus native to the Northern Hemisphere, used in cooking and beverage-making for its wood rather than any edible part. Oak barrels are the standard vessel for aging whiskey, bourbon, wine, and other spirits; the wood's porous structure allows slow oxidation and the extraction of tannins and compounds like vanillin, contributing flavors such as vanilla and caramel, especially when the barrel interior is charred or toasted. Oak wood chips, chunks, or planks are also burned or used as a cooking surface to smoke meats, fish, and cheeses, notably in American barbecue.