I am running 2 players through the Way of the Wicked AP, a summoner and an alchemist. Both are new to these tabletop RPGs.
One of my players managed to obtain some Brown Mold.
As for how she obtained it:
Act 2: The nine lessons.
In the second room of the nine lessons there is some violet mold(brown mold) on one of the doors and the room is very cold.
Upon seeing the mold one of my players (having no idea what it is, everyone failed knowledge check), pulls out a jar and runs over to take a sample (move over, full round action to collect, move away). Thanks to low damage rolls she does this without going unconscious.
They then throw a lit lantern at it to try to burn it, however that causes it to grow. After several fruitless attempts to bypass it they eventually backtrack and find some alchemist ice which they use to kill it.
All the player knows is fire makes it grow and cold kills it. She would now like cultivate it and be able to weaponise it. Given 3 months in game downtime, the character would have had plenty of time to study it.
So I put it to the community, how should I treat a vial of this being thrown in combat, it does not have to be as virulent as brown mold would normally be. And how would it interact if a vial of alchemist fire being thrown in the following round.
My initial thought for this was to treat it as Liquid Ice that lasted a random number of rounds.