the new Noma Guide to Fermentation has a genius low cost solution for this: use a ziploc bag and fill it with water. You just have to not overfill it so you can get it into the mouth of the jar. I did this for a batch of kim chi I just made and it works like a charm.
They totally stole that from me. I’ve made pickles using that method for years. But fill the ziploc with brine, not water, in case it leaks.
How did it turn out?
If I recall correctly, it turned out well. On the other hand, I still have some, and it’s been four months, if that’s any measure of success.
I got inspired by this thread and did a batch myself. Mostly just wung it off a couple of those recipes, using mostly cider vinegar, salt, Mexican oregano and the juice of a half a lime. I had to top it off a bit with water, and I filled my ziploc with brine like @small_h suggested.
It’s only been going a few days, but there’s def. action going on–it hisses every time I crack the top. Will taste soon.