Had to put down some notes in order to recognize materials ... still managed to fail, I guess I'm not made to be an alchemist :p
I like the approach you took for this game, it's dead simple but too clever at the same time ! I'm sure if you add some more features like a book presenting the potions and something like money to buy extra stuff like additional potions or a third glass (just giving random thoughts) you can get a nice little game !