While homemade beer or wine tops at about 5 to 15 percent alcohol by volume, moonshine can reach more than 80 percent alcohol by volume [source: California State University, Homebrewing, Moonshine Heritage]. That's an enormous kick.
Regardless of what you're brewing, you determine the alcohol level with a hydrometer. This gadget gauges alcohol content through a series of readings taken during production. It measures the difference in density between pure water and water heavy with yeast converting sugar to alcohol. It's most often used in homebrewing but can be used to monitor distillation, too [source: Palmer].
However, experienced moonshiners may simply give a jar of moonshine the shake test, gauging the density by the size of the bubbles and how fast they pop. The larger the bubbles and the faster they pop, the higher the alcohol content [source: Moonshine Heritage].