This is very interesting, I'm wondering how this compares with kefir whey (not the store-bought).
Have you compared the two? I am guessing since the kefir grains have trillions of bacteria and up to 60 different strains of yeast/bacteria that they would be similar.
I make beet kvass, sauerkraut and drink homemade kefir. There is no comparison between kefir and fermented vegetable made from the grains and store bought kefirs.