Vodka is an alcoholic beverage that can be distilled from a wide range of things: wheat, corn, potatoes, or even apples. Is it kosher for Passover? It depends how it is made.

If it is made from grain, it is 100% not kosher for Passover, since any time grains (wheat, barley, spelt, rye, or oats) ferment, the result is chametz (see What Is Chametz?).

Ashkenazim, who traditionally refrain from eating kitniyot on Passover, avoid alcohol produced from legumes and corn as well.

But vodka made of other substances, such as potato, is permitted—provided that it contains absolutely no chametz ingredients. Before purchasing, ascertain that the beverage is certified as kosher for Passover.

In addition, there are some (including Chabad) who traditionally avoid all alcohol on Passover (with the exception of wine).