Measuring the ethanol content of a spirit is one of the most nerve-racking things a distiller must do. Simple errors, such as misreading a hydrometer, can have serious consequences—think expensive product recalls and costly fines.
Yet with a strong grasp on the basics of how ethanol acts in solution, how to accurately measure it, and how federal institutions want it to be measured, you can go a long way toward reducing the heartburn and headaches.