Vodka is one of the world's most popular distillates. Vodka can be made from any base ingredient, most popular and traditionally are wheat, rye, potatoes and corn. Vodka is distilled above 190 proof and then cut down to be a spirit between 80 and 110 proof.
According to the Vodka Museum in Moscow, Dmiitri Mendeleev a Russian chemist 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. Above this strength, the taste of vodka can have 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.
Vodka by design is the closest thing to an odorless, colorless and tasteless spirit and in Eastern Europe is traditionally drunk neat. However it can provide a nice blank canvas for use in cocktails especially when using it with fresh fruit or fruit purees.