Milled wood from oak trees, used in cooking and beverage-making mainly as barrel staves, planks, chips, or chunks rather than as food itself. As barrel staves, its porous structure allows slow oxidation of the spirit or wine inside, and toasting or charring the wood contributes flavors such as vanilla, caramel, and smoke; as chips or planks, it is burned or used as a cooking surface to smoke meats, fish, and cheeses. American, French, and Spanish oak are valued for slightly different flavor profiles, and heavier toasting generally adds more caramelized, smoky notes.