1.
Wash the lemons well with water.
2.
Place each lemon with the tip facing up and make two vertical cuts down to about 2 cm from the other end of the lemon.
3.
Cover the bottom of the disinfected jar with salt and heap it up about half a centimeter high.
4.
Fill the cut lemons in a small bowl with salt. Put enough salt into each lemon to cover all the flesh. Work it in generously so the salt can preserve the fruits.
5.
Gradually fill the prepared jar with the salted lemons. Leave as little space as possible between the lemons. Press the fruits together so juice is released. The juice should completely cover the fruits. If too little juice is released, cover with additional lemon juice or water. Leave as little air as possible in the jar.
6.
Optional: cover the lemons with cheesecloth to avoid white yeast. Then place the fermentation weight so all the fruits remain below the liquid surface.
7.
Close the jar tightly so no air reaches the fruits. For screw-top jars, open briefly each day to allow CO2 to escape. Otherwise there is a risk of explosion.
8.
Store the jar in a dark place at room temperature. Check from time to time for mold or yeast growth.
9.
Let the lemons ferment for at least 3 weeks. The longer they ferment, the more bitter the flavor. Taste and decide according to preference. Afterward, place the jar in the refrigerator to greatly slow the process down.