The 6 potions needed for the achievement can be brewed in the Room of Requirement after you unlock the room through the main quest and conjure a potion table.
Brewing potions only counts if you have room in your inventory to collect them. You will need to use a potion to free up space. If you are full on Wiggenweld Potions, you need to get hurt first, then press D-Pad Down to heal.
The first Wiggenweld Potion brewed in Potions Class does not count toward the achievement. If you are missing an ingredient, they may be found in the world outside Hogwarts or you can purchase them from either J. Pippin's Potions or The Magic Neep. Both are located in the northwest part of Hogsmeade.
00:00 - Wiggenweld Potion
00:35 - Edurus Potion
00:46 - Maxima Potion
00:59 - Invisibility Potion
01:09 - Focus Potion
01:22 - Thunderbrew