So in a campaign where I play something of a battle-chef character (cullinomancer homebrew prestige class to be specific, it's hilarious) our GM recently presented me with a feat called "culinary ashe" that... I can't remember if it's homebrewed or some obscure D&D material. But it's essentially "brew potion" only that instead of potions the result is magic food that doesn't spoil until consumed.
Anyhow, that's not exactly the important part, just explaining why I'm interested in the following. My character is a gish based in the sorcerer class, so his spell selection is kinda limited. He's a half-elf though, so that makes him eligible for the paragon surge spell that grants a feat for 1 minute per level, and as I'm sure many of you are aware, one of those feats is "expanded arcana" which allows the addition of extra spells known for as long as he has the feat (which isn't very long).
So basically it pretty much literally boils down to: can one cast paragon surge, grab a specific spell and use that to create a potion? I'm suspecting that it's not rule legal because a potion takes a day to brew, which of course is much longer than the duration of the spell. But I'm kind of unsure how it works. Does one only have to "know" the spell long enough to cast and imbue the spell into the potion and then just let the potion brew in peace after that without further imput from the caster or does the potion creating require that he actually know the spell for the full duration of the brewing?
My GM did admittedly say that he'd allow it, but I'd rather not pull this kind of trick if it's not rule legal. Especially since he also made the edit to the feat that removes the upper limit of spell level, whereas I'm fairly certain that the regular only goes up to lv4 spells.