This is for a fantasy-themed game, but since I want a word that is a real English word this seemed an appropriate place to ask.
I'm looking for a word to describe a category of processes applied when combining reagents/reactants, such as applying heat.
"You create a potion by combining reagents by means of a __________ [generic word that could cover a process like heating/chilling/steaming/mocking]"
In a culinary context one could use "cooking" generically to cover various methods like sauteing, boiling, roasting, etc.
A single word would be ideal, but a 2-word phrase would probably work as well. It would not need to be common in modern English, but would need to be recognizable as English.