Fermentation is suppose to bring the chemicals out of the leaves. Otherwise id have to mulch the leaves and eat them which is hard on the stomach. Yeah the light shining on the jar heats it up and the light does something with the plant chemicals and makes the whole thing bubble. Its important to leave the lid a little vented so gases can escape.
Hmm maybe that would help, idk... if I have a bunch of plants its something id give a try.
So true, discovery is half the fun :-)