When you have a beverage that you don’t know what the alcohol content of, either because you didn’t take an original gravity reading or you lost your notes or whatever, a way to find that out is with a Spirit Indication Test.
- Take a gravity reading with your hydrometer. Write this down.
- Take the temperature of your sample. Write this down.
- Boil your sample down to half. So if you had 6 ounces, boil it down to 3 ounces.
- Add distilled water back to your sample so you are back to the original amount. So if you had 6 ounces, and you boiled away 3 ounces, you would add 3 ounces of distilled water.
- Cool the sample down to close to your original temperature (within a couple of degrees is fine.)
- Take the gravity reading once again. Write this down.
- Take the temperature once again. Write this down.
- Taking the numbers you jotted down in steps #1, 2, 6 & 7, and plug them into the form below to find out the ABV.