Now that you have either purchased or prepared your own spore syringe - it is time to prepare the substrate‚ which is the sterilized mixture of organic brown rice flour‚ course ground vermiculite‚ and water. Commonly referred to as a substrate “Cake”. It is important to purchase “organic” brown rice flour because it will be guaranteed to not have been treated with a fungicide. Obviously a fungicide would prevent the germination of the mycelium because the mushroom is a fungus! Also it needs to be the “brown” kind because of its higher profile of vitamins and minerals required for healthy mycelial growth. The vermiculite must be the course kind because this provides for proper aeration‚ which is needed for the necessary gas exchanges of oxygen and carbon dioxide.

It is relevant to be aware of the fact that mushrooms are not like plants in regards to this gas exchange. They absorb oxygen and expel carbon dioxide just like humans do. They also do not require photosynthesis to produce energy like plants do. So don’t mistake a mushroom for a plant‚ because it is simply something entirely different. An organism that belongs to its very own biological classification known as: yep‚ you guessed it - the “Fungi Kingdom”. Ok‚ enough of the scientific background information. Let’s get to learning about substrate preparation.

Make sure your work area is generally clean. It doesn’t have to be impeccable at this stage because everything will ultimately be sterilized in the pressure cooker. First take your lids and using the hammer and nail - poke (4) four equally spaced holes in the tops near the edges. This is where you will be inserting your spore syringe later. Ok‚ very simple‚ now just measure out the following amounts for each individual cake you want to make in the large mixing bowl:

• Vermiculite = 2/3 Cup
• Brown Rice Flour = 1/4 Cup
• Distilled Water = 1/4 Cup

Again‚ simply multiply the above amounts by the number of desired cakes you want to make. Start with the vermiculite‚ then add the flour‚ and finally add the water. Mix all of these ingredients well. Fill each jar with the mixture leaving 1/2 inch of empty space at the top of the jar. Wipe this space clean with a moistened paper towel so that you don’t accidentally leave a “bridge” or “wick” of substrate for a competitor organism to invade later.

Now fill this last half inch of the jar with pure‚ dry vermiculite. This will act as your “casing” layer. Screw the lids in place and cover them with the aluminum foil. Place a reasonably thick washcloth in the bottom of the pressure cooker (this will prevent the bottoms of the jars from overheating so they don’t crack). Place the jars in the pressure cooker. Close the lid. Now this next step is pretty much a repeat from the chapter on creating your own spore syringe except for minor variations‚ it is as follows:

First make sure the pressure cooker is clean. Wash the outside with bleach. Add enough regular tap water so that it’s level rises about 3/4 of the way up the sides of the jars. Place the pressure cooker lid in position. Leave the stop-cock open while heating on “high”.

When you see high pressured steam emitting from the stop-cock‚ it is time to close it with the pressure regulator. Set the regulator valve to use the 15 psi setting. After a few minutes you will have to adjust the heat level based on the “jiggles” and “rattles” you hear coming from the regulator. You don’t want it jiggling non-stop. So turn the temperature down until you hear a jiggle every (10) seconds or so.

Let the jars sterilize for about 30 - 45 minutes. After the required time has passed‚ turn off the heat‚ soak the paper towel in the alcohol‚ and wrap it around the pressure gauge and stop-cock. Let the entire system cool to room temperature. This will take a few hours.

If you don’t take heed to that last little bit of advice‚ then you will risk having all of the sterilized water boiling out of all the jars and allowing contaminants to filter in.

After the cool-down‚ take the pressure cooker to the work area. Wipe the entire outside down with either peroxide or undiluted bleach. Also make sure the area is cleaned as mentioned in Chapter 2 ‚ The “Sterile” Work Area. Take the “clean” Rubbermaid container and place it on its side. Mist the inside with peroxide. Have your gloves and mask on. Take out the jars‚ leaving the aluminum foil in place for now. Place the new spore syringe in the container.