To the check the alcohol content of your homemade wine or alcoholic drink, you need to use a hydrometer or a vinometer.  This is the best way to determine alcohol content of homemade wine.

Hydrometer:

Much more accurate and naturally a little bit more complicated. Hydrometers can vary in size but for home wine making, these are definitely the best. You simply drop one of these in your batch before you add the Home Booze Mix, jot down the proper ratings and than do the same after the 4 day process.

Vinometer:

Much smaller than a Hydrometer and somewhat less accurate. A vinometer unfortunately only works best with red wine (sweet wine) and not white wine (Sour)