This recipe was adapted for fresh from The Dosa Kitchen by Nash Patel and Leda Scheintaub. Kanji is a cultured, probiotic-rich beet beverage that hails from the Punjab region of India. Its salty, pungent punch is an instant perk-me-up. For your first batch of kanji, use 1/4 cup juice from a jar of naturally fermented pickles or sauerkraut, then, for subsequent rounds, use kanji liquid from the previous batches. You can finely ground the mustard seeds using a spice grinder or mortar and pestle.
1 large carrot, scrubbed (not peeled) and cut into 1/2" pieces
1 large red beet, scrubbed (not peeled) and cut into 1/2" pieces
1/4 cup naturally fermented sauerkraut or pickle brine (see headnote)
1 Tbsp. mustard seeds, ground
2 tsp. fine sea salt
6 cups filtered water