When fermenting vegetables, it is very important to keep air from getting into your
container, but also important to let the gases out that are produced by the act of
fermentation. This can be achieved in a few different ways- by placing a weight on your veggies to keep them submerged, using an airtight lid and burping the container regularly, or using an airlock.
One of the easiest ways to do this is by using an airlock (yes, just like the kind they use for beer & wine making!). This device keeps air from getting in while allowing the gases to escape. It also fits nicely on a quart or half gallon- sized canning jar, making it easy to create smaller batches that tuck right into the fridge when ready.
To use: Remove small cap at the top of airlock. Add water into the top of the airlock (fill to the line), and replace the lid. This water creates the barrier that keeps air from getting in. The gases produced during fermentation can bubble through the airlock and out.
Insert the bottom of the airlock into the hole on the lid, place lid on top of jar, & secure with ring. Be sure to allow some headspace on the top of your jar (1-2 inches).
Allow your veggies to ferment at room temperature. They will ferment faster in warmer weather, and also if they are cut in small pieces, so be sure to check them for crunch factor within a few days. When the texture and sourness is to your liking, they're ready!
After that jar is empty, be sure to save any leftover juices - you can drink them like a gut shot, use them to jump - start your next batch!
Using an Airlock for Vegetable Fermentation