Introduction: Growing Mushrooms: PF Tek
Video of some time lapses that I've done
Step 1: Supplies to Begin
To begin growing your own mushrooms you will need the following for the PF tek:
Check thrift stores such as savers and goodwill, also browse your local craigslist.org listings for a cheap pressure cooker, my 8 quart set me back $50, the single most expensive peice of equipment to begin growing.
-Organic brown rice flour
I found the rice flour at Sprout's grocery, any health food or organic food store should sell this.
Found at nurseries, skip the big home improvement stores
I found perlite at Home Depot, but this can also be picked up with the vermiculite at a nursery
-Canning jars (Ive seen 1/2 pint used alot, as well as 8oz and 250mL jars)
Safeway, but any department store, even craft stores. Be sure to use wide mouthed tapered jars! To find out why check step 11
Can be found online, or local shops, depending on species that you wish to grow
-Aquarium/Terrarium/Large tupperware (for humidity chamber)
I found a nice medium sized aquarium for $9 at a thrift store
-Hammer and Nail
- Alcohol lamp or lighter
Step 2: Preparing Your Jars for Spore Syringes
Spore syringes are the easiest way to get started growing mushrooms with this technique. They can be ordered online from a variety of sources.
To prepare your jars, you will need a hammer and nail.
Remove the jar lid and lay the flat lid rubber side up on a table. Take a nail and make 2 - 4 holes evenly spaced around the edge.
NOTE: In the pictures I put holes through the jar lids facing the wrong way ... with the rubber side down. The sharp edge around the hole can tear the foil in the next few steps.
Step 3: Mix the Substrate
The substrate is what the fungus will feed off of. It will consist of brown rice flour, vermiculite and water. First, take the dry ingredients and mix them in a bowl. After they are well mixed add the water.
For 12x 250mL (~8oz):
-9 cups vermiculite
-3 cups brown rice flour
-3 cups water
For my mixing bowl I halfed the amounts above and mixed only half the substrate at a time.
I have heard of adding 'worm castings' (earthworm poop) to substrate to give better flushes of mushrooms.
Step 4: Fill the Jars
Once your substrate is well mixed and moist, begin filling your prepared jars with the substrate. Don't pack the mixture down, just loosely fill the jar.
Leave about 1/2 inch of space between the substrate and the top of the jar. I just filled my jars up to the threading for the lid.
Be sure to wipe up any moisture/substrate on the 1/2" inside and outside the jar.
Fill the rest of the jar with dry vermiculite. This is to make a barrier between the substrate and contaminants in the air.
Step 5: Get Your Jars Ready for Sterilizing
Now close up all your jars, with the rubberside facing upwards (upside down from how they were designed)
Place a square of foil over the lid covering the holes and sealing the jar from contaminants in the air. Crumple it down nice and tight, forming it around the jar lid.
Put about 3 inches of water in your pressure cooker and place as many jars as you can, stacking them if you have to.
I had no problem putting jars directly on the bottom of the cooker, but I have seen people put old canning jar rings in the bottom to help prevent jars from cracking.
READ your pressure cooker's manual if you have it! It can be a dangerous tool if improperly used.
Step 6: Sterilization
Close up your cooker and put it on a stove. I used a BBQ side stove to keep heat out of the house.
Start the stove up and wait until the pressure regulator (the ball/weight on top of the cooker) starts shaking. This is around 11-15psi depending on the manufacturer.
Let the jars and substrate sterilize for about an hour.
Once the hour is up, let the cooker stand for about 3 hours to cool down, you can also sterilize in the evening and let it cool down overnight.
Step 7: Inoculation
Inoculation is the process of introducing spores of your chosing into the sterilized substrate to take hold and grow.
In this step, be sure to take precautions to prevent contamination of the jars!!
Leave the jars in the pressure cooker until you are ready to Inoculate.
It is best to use a cleaned small room (such as a bathroom), HEPA flow hood or glove box when Inoculating.
Here is the basic order of things during the Inoculation procedure:
1. Open the pressure cooker
2. Remove a jar
3. Heat the syringe needle until it is red hot, with either a lighter or alcohol lamp
4. Remove the foil
5. Insert the needle into the hole you punched with a nail earlier
6. Inject some (about 1ml or so) of the spore saturated fluid into the substrate, on the wall of the glass jar. You should be able to see the needle tip and the water run down the side of the jar.
7. Repeat with the other nail holes
8. Replace the foil and continue with the next jar, reheat the needle if it touches anything unsterilized or every 3 or so jars to prevent contaminations.
See the second picture on this step for an example of contamination, green penicillium mold is a common contaminant. Yellow and pink discoloration is another sign of contamination.
Step 8: Incubation
Now that the hard part is over, you just need to let the jars rest somewhere warm and dark. Like in a cupboard above the refridgerator, or in a cardboard box by your computer tower.
This allows the spores to incubate into mycelium the body that absorbs nutrients and water.
Keep them around 80-86 degrees F. It will just take longer for the mycelium to grow if it isn't near the optimum temperature.
It takes around 3 to 4 days to see the first hairs of mycelium forming as white spots and 3 to 5 weeks to let the fungus get to a 100% foothold in all the substrate, depending on temperature conditions.
Step 9: Science: Mycelium
Mushrooms are part of the basidiomycota phylum which reproduce using spores (basidiospores) created on the gills (basidia) of the mushroom.
Hyphae is the stringy organic material making up the mycelium. When hyphae from 2 different mycelium bodies meet they share genetic material and create a dikaryotic, secondary mycelium structure from which the fruit bodies (basidiocarps) form.
That is why we inject spores in multiple places to create more than 1 mycelium body!
The following pictures show progress of the growth.
Step 10: Fruiting Chamber
A simple fruiting chamber can be fashioned out of an aquarium or a large tupperware box.
The main purpose of the chamber is to create a high humidity (90% to 100%) environment for our mushrooms to flourish.
To easily humidify the chamber, fill a strainer with your perlite and soak it in a bowl of water for 5 to 10 minutes, drain it, and line the bottom of the container with it. This will allow the water to slowly evaporate to create high humidity.
Place squares of aluminum foil where you will be putting your substrate cakes in the next step.
Be sure to use some sort of cover to keep the humidity in the chamber. If you can drill holes into the sides of the container to allow air exchange, the mushrooms produce CO2 and require O2 to live!
Step 11: Birthing Your Cakes
Birthing is a fairly simple process of taking the foil and lid off the jar, flipping it upside down on a paper plate or peice of foil and giving it a few smacks downward to dislodge it.
After birthing it is a good idea to soak the cake in water for about 24 hours. Temperature shocking the fungus by soaking it in the refrigerator causes the fruits to appear quicker than a room temperature soak.
I have also seen methods that roll the cake in dry vermiculite after they have been soaked and birthed.
Remember that mushrooms are 80 to 90% water!
Step 12: Wait for Your First Flush
It takes about 2 weeks for the first flush to complete growing depending on the species.
The cakes should last for about 3 or 4 flushes, in which you may "dunk" the cakes for 24 hours between flushes to rehydrate it.
If you plan on picking the mushrooms, just grab them from the base with your forefinger and thumb and break it off at the base. They can either be cooked fresh, freeze dried or air dried for cooking later!