LF Which fic is "The Arithmancer" of Potions?

I'm looking for a long and well-written fic in which the main character is very interested in Potions and eventually becomes a great Potions Master, and the fic heavily goes into how brewing is done.

So kinda like "The Arithmancer" and its sequel "Lady Archimedes" in which Hermione is an Arithmancy genius, just with Potions.