Said to be based on a 15th-century recipe created by a monk named Isidor who lived within the walls of the Chudov monastery in the Kremlin – note the use of the word ‘legend’.

This wheat-based vodka is rested in copper vats prior to bottling.

Source: https://www.diffordsguide.com/beer-wine-spirits/329/legend-of-kremlin-vodka