The strongest possible spirit that can be produced is approximately 95% alcohol, or just over 190 proof. Alcohol proof is a classification system for alcohol content that is roughly calculated by doubling the percentage of alcohol in a spirit, though the exact calculation formulas may vary by country. Alcohol that is 200 proof (or 100% alcohol) can't be produced by normal distillation methods because once it is exposed to air, the alcohol absorbs moisture and dilutes. The average spirit on the market is roughly 80 proof (or about 40% alcohol), but there are a few legal 190 proof grain alcohols available worldwide, such as the American brand Everclear® and the Irish brand Knockeen Hills Poteen®.
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