Things you’ll Need:
Used coffee grounds
mushroom spawn with sawdust (oyster or shiitake)
a bucket/container of 2 to 5 gallon in size
spray bottle
cellophane
1. Fill the bucket or container with coffee grounds. Keep in mind, how much it is filled and draw a line over the top of the layer of coffee grounds. Empty the bucket and put coffee grounds back in their original packaging. *Don’t fill it full.
2. Drill a few holes around a bucket, half-way between the line you just drew and the bucket rim. These holes will be employed later for releasing of CO2, because you’ll cover the top of bucket with perforated plastic film.
3. Fill the bucket with coffee grounds again, if they are dry, moist them. Break the mushroom spawn with sawdust into the bucket and mix this in coffee grounds on top one inch layer so that the spores will distribute well.
4. Now cover your bucket with a layer of cellophane. Poke some holes in cellophane with a pen for air. This will keep your mushrooms in appropriately moist environment and let the air in and out.
5. Keep this bucket in a dark corner of your home.
6. Remove the cellophane cover once a day to lightly spray the coffee grounds from water. Place the cover back when finished.
Care and Harvest
After 15 to 20 days, surface of mushroom substrate will start to change and you will see white patches all over.
When you see this, simply remove the cellophane layer and place your bucket in more light, a shady lit windowsill or less windy corner in your home with some light is perfect. But remember, fluctuation in temperature will be detrimental, so the place should be warm and stable.
Do not let the surface to dry out, spray the water twice in a day. Mushrooms love moist and humid substrate.
Within a week or so you’ll see tiny mushrooms emerging and in a few more days, when these mushrooms will turn fleshy and their caps turn upward, you can harvest them.