Mince garlic. If whole cloves are preferred, skip this step.
Mix 2 cups water and 2 Tablespoons of salt in a liquid measuring cup to make a brine. Allow salt time to fully dissolve.
Fill two wide mouth pint jars or a small fermentation crock with garlic. Press it down tightly and add a fermentation weight.
Pour the brine over the top until it covers the garlic completely. Stop when it's about a quarter inch above the garlic. You'll likely have extra brine leftover and don't need to use it all.
Add a fermentation lid (airlock, pickle pipe, homemade, or waterlock seal).
Store in a cool, dark area, 65ºF is ideal, for 2-3 weeks.
When the ferment is finished, store in an airtight jar in the refrigerator. The fermented garlic will store for up to one year.
Notes
If your garlic turns blue in the fermentation process, don't worry. This is a normal chemical reaction between enzymes and the sulfur in the garlic. It's safe to eat! It happens to me almost every time I make fermented garlic.
Minced garlic will ferment faster and usually only take about 2 weeks for fermentation. Allow the full three weeks for whole garlic at ideal conditions of 65ºF
The intention of the brine is to just cover the garlic and then stop. You'll likely have some leftover, depending if you leave the garlic whole (uses more brine) or mince it up (uses less brine). You can dump the extra or save it in the refrigerator for another batch later on. If you use too much brine over the top the ferment will not be as good.