For those interested in recycling and/or using creative materials as mushroom substrate, you can grow mushrooms on coffee grounds! If you’d like to try this, you’ll want to use fresh coffee grounds from within a few days (2-3 days tops) of when they were brewed. This works especially well for growing oyster mushrooms and growing lions mane mushrooms.
If you don’t drink enough coffee to fill a bucket with coffee grounds in that amount of time, many coffee shops will gladly share their coffee grounds for free – Starbucks even has a wonderful program called Grounds for Your Garden where they give away their coffee grounds for free to use for growing your own mushrooms or composting for your garden. Many of their stores actually have them pre-packaged and ready to give away – pop into your local Starbucks to see if they have any available, if not, drop your local coffee shop a note and see if they’d be willing to share theirs (if they do, it’s nice to bring them some of your mushroom harvest or set up a bucket for them as a thank you! We’re incredibly grateful to our local baristas that keep the team (and mushrooms) at The Mushroom Conservatory in motion.