The strongest possible alcoholic beverage that can be produced is about 95% alcohol, or just over 190 proof. Alcohol proofing is an alcohol content classification system that is roughly calculated by doubling the percentage of alcohol in a drink, although the exact calculation formulas may vary by country. 200 proof alcohol (or 100% alcohol) cannot be produced by normal distillation methods because, once exposed to air, alcohol absorbs moisture and dissolves. The average alcoholic beverage on the market is around 80 proof (or about 40% ABV), but there are some legal 190-grain spirits available around the world, such as the US brand Everclear® and the Irish brand Knockeen Hills Poteen® .
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Pure alcohol can be created in a laboratory in a process known as azeotropic distillation, which uses pressure to keep the alcohol and water from separating, but this solution is not typically sold for recreational use.
The process of determining alcoholic strength dates back to the 17th century, when gunpowder was poured over liquors and set on fire to “test” the strength of their alcoholic content based on how long the flame remained lit.
The average beer is 10 proof, while the average wine is around 26 proof.