Gather the following basics:

  • Vermiculite (available online or locally where garden supplies are sold)
  • Brown rice flour (best to grind it fresh from whole brown rice) or buy from a health food store
  • Purest water available
  • Pressure cooker (one that can hold at least six six-ounce glasses with wide mouths)
  • Round trivet that fits the bottom of the pressure cooker
  • Sterilization supplies (anti-bacterial soap, bleach, etc.)
  • Aluminum foil (the heavy duty kind)
  • Mushroom spores in a syringe (available from

Six 8-ounce glasses or jars (tapered, no “shoulders”)

Either wash your hands with antibacterial soap or use latex gloves that have been wiped thoroughly with alcohol. Be sure your personal hygiene is impeccable, including your hair and clothing.

Fill the glasses to within half an inch from the top with vermiculite, so that you don’t make too much of the substrate. Then dump them all into a sterile bowl.

Add enough purified water to wet all the vermiculite and stir to the point where just a little water appears when you tip the bowl slightly, and the vermiculite has absorbed the rest of it.

Then sprinkle brown rice flour over the vermiculite and stir to coat. Keep adding the flour only until everything is just coated.

Sterilize the glasses by boiling in the pressure cooker for 90 minutes … after the water starts to boil … turn the heat to low then, but just high enough to create steam, and watch the cooker so it doesn’t boil dry.

Fill the six sterile glasses loosely with the mixture up to half an inch from the top, dividing evenly among the glasses.

Then fill the glasses to the brim with dry vermiculite, shaking each glass to level it.

Tear off a piece of aluminum foil wide enough to cover a glass and fold in half lengthwise. Do this for each glass and cover each with the folded foil and fold down the edges to seal and create a neat little lid.

Tear off another piece of foil wide enough to cover a glass and divide it in two and cover two glasses loosely but with the edges folded down enough so the foil doesn’t fall off. Repeat for the rest of the glasses.

Put the trivet in the bottom of the pressure cooker, add to bottom of trivet, and set the six glasses on top of it. (If your pressure cooker is large enough, you can actually make a double batch and use 12 glasses instead, stacking the second six on top of the first six.)

Secure the lid, and pressure cook for one hour.

Turn off the heat and let the cooker cool completely. Remove the glasses and loosen the top layer of foil only.

Take your needle full of spores and sterilize the tip to red hot, using flame from a candle or small burner. Sterilize it again between each glass.

Lift the top layer of foil off and inoculate each glass four times in a square pattern, holding the needle at an angle so that the solution runs down the inside of the glass.

Put the foil back on the glass and tighten it to the “cap” piece.

Now you will have to wait for the spores to germinate and the mycelium to populate the vermiculite (the substrate) for three weeks, keeping the temperature between 75 and 81 degrees Fahrenheit, 24-28 Celsius.

If you see Trichoderma, the forest green mold, growing in any jar, simply toss it out, jar and all. Otherwise, you chance the mold infesting you, your hair, your home, etc., and it’s very sticky and hard to get rid of and may ruin future projects.

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