I’ve found the fatal flaw in my first fermented green bean experiment, putting plastic wrap over the mouth of the glass jar kept the fermentation gases from leaving. This meant that the gases built up until it had enough pressure to spill the water that was weighing the plastic wrap down, over the top of the jar. So I went back to the drawing board.
I finally came up with an ingenious (if I do say so myself) design. A couple weeks ago I melted part of a flimsy plastic sheet cutting board, I didn’t throw it out, but it was warped enough that it was annoying to use. Yesterday, I cut out circles about 3/4 inch wider than the mouth of the jars, and then cut the circle down the radius. This works perfectly to keep the green beans under water because it is easy to insert, but once it pops back into shape below the neck, it can’t works its way back out on it own. The gases can escape around the sides, and it requires minimal fuss.
So far it is an almost perfect solution. My only complaint is that I am trying to do these experiments as old-fashioned as I can, and I somehow doubt that plastic sheeting can even remotely qualify as old-fashioned. I am tempted to just find a rock about the size of the opening, but I’m not sure if that would effect the quality, or if it would leech too many minerals into the batch of green beans. Although I’m sure that the plastic, even though it is food grade, is leeching all sorts of chemicals into the batch as well. Which is the lessor of two evils? I just don’t know, but I am going to be on the lookout for right sized stones, and maybe I will give it a try.