Should you use 80 proof or 190 proof for your tinctures? I see this asked a lot so I wanted to make a post.
The idea of "proof" in alcohol goes back to 16th-century England, when the government needed a way to tax spirits based on strength. They tested liquor by soaking gunpowder with it; then tried to light it with a match, if the liquor lit then it was "above proof" and taxed more. Other countries have different proof systems, but in the U.S., proof is simply double the alcohol percentage (so 50% alcohol equals 100 proof. And the rest is water).
So, which “proof” is best in tinctures? I see lots of comments with opinions that it’s always best to use vodka or best to use 190 proof. But, the reality is that it depends on the plant! There is no “one stop” solvent to use. And within each proof category there are several types of alcohol you can choose. For 80-100 proof it is often Vodka because it has a neutral flavor, but you could also use brandy (goes great with elderberries) or other liquors, as long as your final tincture has over 30% alcohol to preserve it. You can have an infusion mixed with alcohol. Glycerin. Or, a dual extraction (of high proof tincture and a water decoction prepared separately then combined.) Some is personal preference and flair. And some of it is knowing the plants and what compounds you want to extract.
I created a chart as a general guide but choosing the right menstruum to use is much more nuanced than this. This is a start!