Mushrooms are an invaluable addition to any garden, and many people take a try at growing them themselves in different ways. While most tend to rely on soil for mushroom cultivation, other substrates, including wood shavings or coffee grounds, can be equally successful. With coffee grounds as an example, no additional sterilization process is necessary as the brewing process has already sterilized them while also being an excellent source of nitrogen and other essential nutrients necessary for their development.

A common method for growing mushrooms from coffee grounds involves filling half of a glass jar with waste product and adding mushroom spores from an open bottle, before placing the lid closed and keeping in a dark location with misting water every couple of days to maintain an 85% relative humidity level, ideal for mushroom growth.

If you want to try your hand at mushroom cultivation with coffee grounds, the first step should be sourcing your raw materials. Visit your local coffee shop and inquire if any spent grounds are available, or purchase fresh spawn online from one of many retailers. Once you have them on hand, the rest of the process should be straightforward.

As soon as you’re ready to begin cultivating mushrooms on your own, it is vital that the soil you use is sterile. To eliminate all unwanted bacteria from growing in the substrate and ensure optimal aeration for mycelial development. A great way of doing this is mixing spent coffee grounds with straw or sawdust which will increase airflow while decreasing compactness that could impede mycelium formation.

Ideal ratio for this mix includes 70% coffee grounds, 20% straw and 10% spores. Although this ratio can be modified to suit your desired outcome of cultivation, many find that mixing these components together proves more successful than cultivating only pure coffee grounds, since mycelium produces enzymes capable of breaking down lignin found within coffee grounds.

Once the mycelium has fully colonized the coffee and straw mixture, it is time to start monitoring mushroom development. Look out for small “pinheads” appearing at the center of your container, before moving it into an area with indirect sunlight for best results. When enough pinheads have grown into full size pinheads it will be time to harvest your new crop!

There are various species of mushrooms that can be grown successfully in coffee grounds, from oyster mushrooms (Pleurotus ostreatus) that grow quickly and colonize substrate quickly, to slow-incubating varieties like Shiitake mushrooms (Lentinula edodes). No matter the species of mushroom being used as substrate – coffee grounds provide an ideal medium in which these edible organisms thrive! Under ideal conditions they produce delicious and nutritious meals in no time!