Possible Clues:

• Alcoholic drink from Russia
• What's still produced in Russia?
• Dave almost OK drunk -- with this?
• Spirit made from rye, wheat or potatoes
• Spirit is very aged finally in conditioned oak
• Sour option
• Spirit of Russia
• Russian spirit distilled from rye or potatoes
• Spirit of old duke regularly seen in V&A
• Spirit traditionally made from fermented grains or potatoes