If you’ve always wondered how strong alochol was made, then check out this interesting “How it’s Made” segment. Video after the jump.
The concentration of alcohol in an alcoholic beverage may be specified in percent alcohol by volume (ABV), in percentage by weight, or in proof. The ‘proof’ measurement roughly corresponds in a 2:1 ratio to percent alcoholic content by volume (80 proof ≈ 40% ABV). Common distillation cannot exceed 191.2 proof because at that point ethanol is an azeotrope with water