Is there a coded way to test if materials can be brewed into something, like you can test for crafting? Or is brewing all trial and error / finding a teacher :?:
Yes, there is a method. It's something you'd probably want to learn about ICly - by finding a teacher or experimenting with the various perception-related commands (not necessarily perception-related skills). You'll probably hit on it by yourself eventually, so don't give up hope if you become frustrated :)