You will have noticed that the definition for NGS uses the words “any material” and that Vodka is an NGS that has been “filtered with charcoal or other materials” so the notion held that Vodka is made only from potatoes is incorrect, in fact most Vodkas are made from wheat and they always have been. Vodka came into existence before potatoes made their way from the new world to the old world (and don’t get me started on how potatoes were considered peasant food and that a Czar or other Royalty would never drink something made from peasant food… but I digress.)
Traditionally, high proof Spirits have always been made from excess product you would have on hand. You could either throw away a crop or you could transform it into a high proof liquid that doesn’t spoil (and was in demand).
Today Vodkas are made from wheat, rye, corn or any grain, potatoes, grapes, again anything you can distill to 95 % alcohol. In Oregon there is a rice Vodka and I have had a vodka made from apples.
For a really good read try The King of Vodka: The Story of Pyotr Smirnov and the Upheaval of an Empire (P.S.) by Linda Himelstein.
--Christopher M Neumann