An alchemist can add formulae to his book just like a wizard adds spells to his spellbook, using the same costs and time requirements.
But it's not mentioned same "Spellcraft check" so I'm confused.
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Sign up to join this communityAlchemists aren't mentioned in the Spellcraft skill simply because the Alchemist wasn't around when the Core rules were written and it's never been updated.
The only key difference between a wizard learning and an alchemist is that alchemists do not need to decipher arcane writings before copying them.
Therefore, to copy a spell/formula to your formula book:
Note that you can take 10 on these checks if "your character is not in immediate danger or distracted".
Lvl Cost 0 5 gp 1 10 gp 2 40 gp 3 90 gp 4 160 gp 5 250 gp 6 360 gp 7 490 gp 8 640 gp 9 810 gp
Being a Wizard or an alchemist is expensive.