Learning how to proof moonshine and other alcoholic spirits is easy as pie. You just need a special testing tool called an Alcometer, and a clear test tube if you’re feeling fancy. I recommend using a plastic test tube over glass to lower the chance of breaking it. Either test tube you choose, but ensure you don’t run hot or cold water on it if the tube is the opposite temperature – it will crack!
To measure the moonshine’s proof / alcohol percentage, pour the spirit in the test tube and drop in the Alcometer. Since alcohol affects the spirits gravity, the Alcometer will float based on the percent. Now reach the number which sits at the liquids surface.