I cut them into pieces and submerge them in a salty brine. To prepare the brine, I dilute the salt in water by boiling both and then allowing them to cool down to avoid killing the beneficial microorganisms. I then place a weight, typically a smaller jar filled with water, on top to keep the onions submerged.
After around 10 days of fermentation, you might notice some white bits on top. It’s important to distinguish between harmless Kahm yeast, which appears as a fine white layer, and harmful mold. Kahm yeast can be removed easily before refrigerating the ferment. Factors such as insufficient salinity, high temperatures, or excessive exposure to oxygen can contribute to the formation of Kahm yeast. In my case, the open fermentation setup may encourage its growth, but I accept it and simply remove it post-fermentation.
To prevent the formation of yeast, you can use more professional fermentation setups with jars equipped for automated oxygen release. Alternatively, you can close the jar with the lid after placing the weight on top and open it daily to release accumulated CO2. However, in my setup, the jars aren’t spacious enough to accommodate both the weight and the lid without compromising the pressure on the ferment. Ultimately, to prevent the growth of harmful mold, the weight ensuring to keep the ferment submerged is more crucial than sealing the jar with a lid. Perhaps one day, when I can stay in one place for a bit longer, I’ll have a collection of larger jars to advance my fermentation process further.
