Hi everyone, here's the update of my experience. I start a new tribe, and after I got the cauldron, I made the magic stew. No star-like things were on the stew, but I made my villagers eat it anyway and forcefully drag them to the waterfall. None of them dive to get the piece of gong.

Do you have to buy up to level 3 of Farming or something before making the magic stew?