How to Harvest Your Own Mushroom Spawn

Making Agar Gel

• 1

  Boil the potatoes in 4 cups of water for one hour. Drain and reserve the water, then add agar, sugar and yeast and stir thoroughly.

• 2

  Divide the mixture between the two bottles, plug the mouths with cotton and cover with aluminum foil. Cook in the pressure cooker at 15 psi or 250 degrees F for 15 minutes. Allow to sit for 45 minutes to let the pressure reduce.

• 3

  Remove the bottles with oven mitts and swirl gently to mix the medium. Fill each test tube one-third full and tighten the caps.

• 4

  Process the test tubes in the pressure cooker at 15 psi or 250 degrees F for 30 minutes. Allow the pressure to reduce slowly after processing.

• 5

  Remove the tubes and prop them up so that they are slanted and create the maximum surface area for fungal growth. The medium will harden into a gel as it cools. If you don't plan to use the agar gel right away, store the tubes in a plastic bag in the refrigerator.

Sterile Culture

• 6

  Clean a work surface with soapy water and a 10 percent bleach solution, then wipe dry. Light the lamp or torch and sterilize the knife blade in the flame.

• 7

  Break off a piece of mushroom and rest it so that the inner surface does not touch the tabletop.

• 8

  Hold a test tube horizontally with the agar surface facing up. Remove the cap but do not allow it to rest on the tabletop or any other potentially contaminated surface. Continuing to hold the test tube horizontally, carefully cut out a small piece of mushroom from a clean inner surface and use the tip of the knife to place it inside the test tube. Replace the cap on the test tube and tap it so that the mushroom piece rests on the agar gel.

• 9

  Repeat this process for each test tube, sterilizing the knife blade each time and tearing off a clean piece of mushroom.

• 10

  Secure the lids on the test tubes with microporous tape and label each with the date and type of mushroom culture. Place the test tubes out of direct light and in a location with a temperature between 55 and 70 degrees F. Mycelium will begin to grow in a few days to a week.

Sterile Transfer to Grain Spawn

• 11

  Add wheat and 1/4 cup of water to the 12 oz. bottle and cover with aluminum foil.

• 12

  Process in the pressure cooker at 15 psi for seven minutes. After the pressure cooker cools, lift the bottles with your oven mitts and shake gently to mix the wet and dry grain. Process at 15 psi for an additional 45 minutes. After the pressure cooker cools, remove and shake the bottles again. If you're not going to use the grain spawn right away, store it in a dust-free location.

• 13

  Light the lamp or torch and sterilize the inoculation loop in the flame. Use the inoculation loop to remove a piece of mycelium from the agar. Drop it into the jar of grain spawn so that it rests on the grain. Close the jar and label it with the date and contents. Shake the jar periodically as the spawn grows in the grain. Once grown, the spawn is ready to use for fruiting mushrooms.