The first records of distilled grains spirits appeared in Ireland and Scotland in the 1400’s. Over time, these spirits became known as whiskey, which is the anglicized version of the Gaelic word uisce beatha (Ish-ca Baa-ha) which means water of life. English colonization spread whiskey making it to both Canada and the United States and the types of whiskey they made evolved based on the grains that grew well in those climates and soils. Before the 1800’s, whiskey was largely stored in barrels simply for transportation. But, around the turn of the 19th century, people noticed that whiskey stored in barrels had a better flavor and aroma and so began purposefully aging whiskey before selling it. As distilling technology improved, it expanded the variety of whiskey styles that could be made to match the preferences of the drinking public.
Vodka can be made anywhere in the world from any fermentable agricultural product. Historically, vodka originated from Central and Eastern Europe though its popularity spread throughout the rest of Europe and North America.
The defining feature of vodka is how it is distilled, not what it is distilled from. Before any spirit can be called vodka, it must be distilled at or above 95% ABV in the U.S. or to 96% ABV in the UK, EU and Russia. Because of this, vodka can really only be made on column stills or on hybrid stills that have enough rectifying plates that will allow the alcohol to reach the required purity.
Vodka sold in the U.S. can have less than 2 grams per liter of sugar added and less than 1 gram per liter of citric acid without any additional labeling. Whereas, vodka sold in the EU may have less than 8 grams per liter of sugar without labeling.
After distillation, vodka can be filtered through charcoal to remove some of the remaining compounds that can make a vodka taste harsh. Some brands claim that specific sources of carbon add a different character to the spirit or filtering through exotic materials such as diamond make their spirit superior, but specific evidence for this is limited.
In the U.S., all vodka is considered to be gluten free no matter what it is made from even if it has not been certified by an outside agency. The labeling authorities acknowledge that the physics of the distillation process makes it impossible for any significant amounts of gluten to remain in the spirit post-distillation.
U.S. labeling authorities have established that “distillation means a single run through a pot still or a single run through a column of a column still.” Therefore, any spirit that claims it was distilled 10 times or 100 times etc. must be based on the definition above.