Vodka Â is a distilled beverage. It is a clear liquid consisting mostly of water and ethanol purified by distillationâ€”often multiple distillationâ€”from a fermented substance, such as grain (usually rye or wheat), potatoes or sugar beet molasses. It may also contain an insignificant amount of other substances such as flavoring or unintended impurities. Vodka usually has an alcohol content of 35% to 50% by volume. The classic Russian, Lithuanian and Polish vodka is 40% (80 proof). This can be attributed to the Russian standards for vodka production introduced in 1894 by Alexander III. According to the Vodka Museum in Moscow, Russian chemist Dmitri Mendeleev (more famous for his work in developing the periodic table) found the perfect percentage to be 38%. However, since spirits in his time were taxed on their strength, the percentage was rounded up to 40 to simplify the tax computation. At strengths less than this, vodka drunk neat (without ice and not mixed with other liquids) can taste "watery", while strengths above 40% may give the taste of vodka more "burn". Some governments set a minimum alcohol content for a spirit to be called "vodka". For example, the European Union sets a minimum of 37.5% alcohol by volume. Although vodka is traditionally drunk neat in the Eastern European and Nordic countries of the "Vodka Belt", its popularity elsewhere owes much to its usefulness in cocktails and other mixed drinks, such as the bloody mary, the screwdriver, the white russian, the vodka tonic, and vodka martini.