All this talk about soaked/sprouted grains reminds me of rejuvelac. Sprouted whole wheat berries are soaked to the point of fermentation .. you drink the liquid and discard (or compost) the spent grains. It's been many years since I've made it, but lately wondering if it might work as a substitute for kombucha since no added sugar is required . I do recall that alternate non-gluten grains will work too, including brown rice or buckwheat.