Percentage of alcohol in whisky

It depends. Whiskey is a distilled liquor, water is usually added after the distillation and then the whiskey is aged in oak barrels to get a characteristic flavor. A whiskey's alcohol content is marked by a proofing label. This proof is an indication of the percentage of alcohol. 100 proof whiskey is 50% alcohol. some whiskeys are 40 proof, on the low end, and others are as high as 180 proof. Moonshine is not whiskey, it is not aged, that can range from 100 proof to 195 proof.