This is an interesting article from Adam Sayner of Fungi Futures on how to very simply grow Oyster Mushrooms on used coffee grounds which would otherwise be a waste product from large cafés. Its a great way to experiment with small scale food growing and to watch the mushroom life cycle in action.
I attended a course run by Fungi Futures last year and found it a valuable experience that inspired me to experiment with using cardboard as a substrate for outdoor mushroom cultivation. I have had great success with these experiments and hope to put together a post on the mushroom patch I created at Middle Ruckham Farm that fruited a few days ago. They were tasty mushrooms!
The article can be found here: Growing Gourmet Mushrooms at Home from Coffee Grounds