Needs to be fermented.
Full material breakdown in the crafting calculator →
5 Onion + 10 Carrot + 1 Pungent Pebbles → 1 Mead Base: Animal Whispers
Unlocks once you have stood near a Mead Ketill of level 1 and picked up each of: Onion, Carrot, Pungent Pebbles.
