This day, Dmitri Mendeleev defended his famous doctoral dissertation, "Сompound of alcohol with water." Today is  not official, but becoming a kind of pleasant stereotype - a Birthday of the Russian vodka. The event of the establishment of an informal birthday of vodka happened on Jan. 31, 1865. That day in St.Petersburg Dmitri Ivanovich Mendeleev defended his famous doctoral dissertation - "The combination of alcohol with water". Some sources tell us that white bread wine was brought to Russia from Scandinavia in the 16 century; other - that 100 years before, from Genoa. There is also some information that in early Russia the hard liquors consumed already in the 11-12 centuries. Fortress of vodka in Russia has never been a dogma. Traditionally it was produced of different grades - 38, 45 and even 56 degrees of fortress.