Whiskey is a spirit distilled from fermented grain mash, such as barley, corn, rye or wheat, and aged in wooden casks; it is drunk neat, on ice or in cocktails. A 50 ml measure has about 110 kcal, all from its roughly 16 g of alcohol, slightly more than one US standard drink (14 g), with no carbohydrate, protein or fat. Cask-strength whiskeys can have 50-60% alcohol and proportionally more calories.