Mushroom kit with included substrate: Sterilize a syringe and inject spawn into the grow bag through the small hole, or into the tray of substrate at several points. Cardboard substrate: Stack the cardboard squares inside a food-grade plastic bag. Sprinkle a little spawn between each layer as you stack. (Break up the spawn by hand if it’s in a solid clump. )[9] X Research source Homemade straw substrate: Wipe a table with 70% isopropyl alcohol. Spread the straw out on the table and break up the spawn over it, mixing thoroughly. Transfer to food-grade plastic bags until they are full but not compressed. [10] X Research source There’s no exact ratio of spawn to substrate, but you can start with a mix that is 2 or 3% spawn by weight. Adding more spawn helps the colony grow faster and resist contamination. [11] X Research source
Most bags included in mushroom kits already have holes, or an air filter system that makes holes unnecessary.
Mycelium can grow at any light level except direct sunlight. Some growers find they get better results with low light on a daylight cycle (real or simulated). However, if you are using straw, too much light can cause grain to sprout and interfere with mushroom growth. The ideal temperature depends on the strain. If your spawn came with instructions for a growing environment, follow them.
Mycelium is white. If you see large patches of another color, mold has contaminated the bag. [15] X Research source Throw the bag away and wipe the area down with isopropyl alcohol before trying again.
Mushrooms will not fruit without light. Provide at least enough to read by during daylight hours. [16] X Research source Use indirect daylight, a grow light that mimics daylight, or (less effective but cheaper) a cool white bulb. [17] X Research source The fungus needs fresh air to clear out carbon dioxide, which prevents fruiting or leads to small mushrooms. Open the top of the bag and ventilate the area with a light cross breeze. Lower the temperature, ideally to 55–61ºF (13–16ºC). Increase humidity to at least 80%, ideally to 90–95%, by running a humidifier or hanging plastic sheets around the grow bag. This part doesn’t have to be perfect, but other conditions can affect the yield, shape, and color of your mushrooms.
If the growing mushrooms turn brown, or new mushrooms start to grow on an older mushroom’s surface, the substrate is probably too dry. If the caps of the mushrooms feel clammy or sticky, the substrate is probably too wet.
If you’re not sure what a fully developed oyster mushroom looks like, wait until the edges of the first mushroom go wavy. This is slightly past optimal harvesting point, but still edible. Pick the other mushrooms just before they reach the size of the first. [20] X Research source Tiny, aborted mushrooms are common in some strains. Leave them in place without picking them.
Preferred substrate (some species need a specially prepared compost) Ideal temperature during colonization Ideal temperature and humidity levels during fruiting (mushroom growth)Lion’s mane, lingzhi, shiitake, enoki, and nameko mushrooms are all good choices for a second project, only a bit more difficult than oyster mushrooms.
Wash your hands with antibacterial soap before handling any part of the operation. Take special care to pasteurize your substrate. If stovetop heating becomes impractical, look into a steam room or chemical treatment. Treating a compost substrate is complex, and may require help from an experienced grower. [21] X Trustworthy Source Penn State Extension Educational organization dedicated to delivering science-based information to people, businesses, and communities Go to source
Not all types of spawn need casing. Ask the seller or an experienced grower for advice. Do not ventilate the area until the tiny “pins” have appeared on the surface of the casing. Ventilating too early will trigger fruiting before the pins have broken through, growing mushrooms underneath the casing.
Temperature can vary significantly between the ceiling and floor of a room. If you’re growing on multiple shelves, put a thermometer at each level. [23] X Research source Strong drafts can be fatal to some mushroom types. Protect the spawn from direct wind.
Spent substrate has a high concentration of salt, which some plants are sensitive to. Leaving it outdoors to “weather” for six months should remove this problem.
A mostly sterile environment is a necessity for making spawn. Before you begin, remove all rugs and curtains that could trap dust. Clean all surfaces with mild disinfectant, including the ceiling. Cover all openings with plastic sheeting, and make an “antechamber” at the entrance with a second layer of plastic. [26] X Research source
