In order to unlock the Witch’s Brew you have to complete the witches quest.
How to get Witch’s Brew
- Start the witches quest: Find her in the cave behind the cactus, and of course answer I can help with that
- Make the potion: Go back to the cauldron and make a Hot Potion (just chili)
- Give her the potion: Choose “Will this potion help?”
- Wait a few minutes
- Talk to Glinda the Witch: Choose Sure, I’ll be back
- Make the potion: Go back to the cauldron and make a Speedy Potion (just Hoof)
- Give her the potion: Choose “Will this potion help?” > Sure Thing
- Lava flower: Top of the volcano
- Rare blue frog: On a rock near the water
- Jellyfish: Go inside the waterfall and look up
- Done: You have unlocked the Witch’s Brew
Now you know how to get the Witch’s Brew, it was not so difficult.