Cask-aged vodka is vodka that has been aged in wooden casks to give it a unique flavor and color. Vodka is distilled from fermented grains or potatoes, then transferred to casks for aging. The aging process can take a few months to several years. The wood imparts its own flavor to the vodka, which can range from sweet and spicy to smoky and woody. The aging process can also add smoothness and depth to the taste.