I have been putting a bit of thought into Potion creation in BBF. As with most crafting in RPG I like that to be "off camera action". Things that happen between games sessions. Sure hunting material or components can happen in game. Or even be the focus of whole games. But I don't want the rest of the party to be waiting around while the blacksmith character hammers away of horse shoes for half a game session.
I think I like the Idea of the player having a cook book of sorts (not unlike a spell casters spell book). The Enchanter will plan out from his cook book which potions he worked on in the down time. A skill check is made for each, Difficulty based on the complexity of the potion. The enchanter starts the game with a successfully created potions.
If a specific potion is needed in game, and is pivotal to the players strategy or what not cauldron time will still be allowed in game.