Sterilize your growing bottles with hot water and an antibacterial soap. Rinse well so no trace of soap remains on the bottle.
Mix the enoki spawn well with the aged growing medium. Pack the mixture into the jars and store in a place where the temperature is between 72 and 77 degrees Fahrenheit and the humidity level is between 90 and 100 percent.
Allow the enoki two weeks to spawn, though the process may take up to a month. You will know they have spawned when you see small roots, or mycelium, appearing. Wait until the entire medium is covered with these roots.
Move the bottles to a place where the temperature is between 50 and 55 F. The level of humidity does not matter. Lower the amount of CO2 the mushrooms get by 80 to 90 percent, if possible. This forces the mycelium to form fruiting bodies.
Harvest your mushrooms when mature, about 90 days after you began the process.