I was recently asked by a friend what the difference between vodka made from potatoes and vodka made from grain was. The short answer? Nothing.
The fundamental distillation process is to extract the alcohol from a fermented liquid. Some spirits, like rum, depend on some of the mash making it into the final product to add to the flavor. However, vodka is ideally flavorless and odorless so it is distilled until it is 95% ABV or higher, filtered several times (typically through charcoal), and then diluted with spring water down to the acceptable 35-40% ABV. Because of this, you ideally end up with a diluted ethyl alcohol. So it doesn’t matter whether you’re using potatoes, rye, molasses, sugar beets, or any other base plant matter used to produce vodka all over the world.
Why, then, is there such a prevalent misconception that vodka is made from potatoes, when most of the world’s vodka is produced from grains? Cost. You see, vodka has been around since the Middle Ages in Poland. Back then, they used the cheapest thing available to them: grain. Every farmer had it and Polish grain was some of the cheapest in Europe through the 15th century. During the 18th and 19th centuries, three key things happened:
1). The price of Polish grain increased.
2). The potato was introduced to Eastern European agriculture.
3). Vodka production was realized as an actual industry.
Since the potato was so cheap and grain was becoming more expensive, vodka producers started experimenting with the potato as a replacement for grain in vodka.
In the mid-19th century, it became a standard practice amongst the industrial producers to make vodka from potatoes. At some point, using potatoes fell out of favor and the original grain recipes began to be used again, but not before the whole “vodka from potatoes” thing became general knowledge.