Blend 1 cup of mixed dried beans in a blender until powdered. Add 1 cup of wheat bran and blend once again until thoroughly mixed.
Break apart one coco peat cube, and place it inside an 18-gallon container. Add one cup of the wheat bran-bean mixture to the coco peat. Mix in one gallon of water to just moisten the coco peat mix.
Open a 13-by-14-inch clear plastic bag on a flat surface and place a 2-inch layer of the coco peat mixture in the bottom. Add half a handful of of milky mushroom spawn seeds inside the outer edge of the bag.
Add another 2-inch layer of the coco peat mixture and then a half handful of milky mushroom spawn seeds inside the outer edge of the plastic.
Add a third layer of the coco peat mixture and a handful of the milky mushroom spawn seeds. Close bag with twist tie.
Repeat steps 2 through 5 for the second plastic bag.
Make six puncture holes on the bottom and around the sides of each bag. Because the soil is moist, none of it will spill out of the holes.
Place the prepared bags inside a 20-gallon aquarium. Place a sponge in a plastic dish and fill with water. Place this inside the aquarium to achieve high humidity in the aquarium. Cover the aquarium and wait 22 days.
On the 22nd day open the aquarium and clip off the top of each bag. Notice the white mycelium that has grown through the coco peat. Sprinkle 1/2 cup of the wheat bran-bean blend on top of the growing mycelium. Refill the sponge dish with water, replace the aquarium cover, and do not disturb for four days.
Mist the bags on day 27. When mushrooms have grown 6 or 8 inches tall they are ready to harvest.
Check mushroom bags daily and mist to keep the soil moist for the next three months. Harvest mushrooms every three to four days by twisting and pulling them from the bag. Refill the dish holding the sponge with water as needed. Keep aquarium covered to maintain humidity.