Spore syringe. A spore syringe will contain the mushroom spores needed to inoculate the substrate and begin growing.
Vermiculite. Vermiculite is a porous, inert substance that we will use to maintain moisture content inside the cases and provide space for the mycelium to grow. The fine ground vermiculite is preferable, but course vermiculite will also work.
Mason jars. We'll be using wide-mouthed 240ml (approximately 1/2 pint) mason jars to house the cake and provide a sterile, humid environment for the mycelium to colonize until they are ready to bear fruits.
Flame. We will use the a flame to sterilize the spore syringe's needle between the inoculations of each jars. A butane lights, gas stove or alcohol lamps will all work just fine.
Step 1. Preparing the Jars
The substrate is made of vermiculite, brown rice flour, and purified water.
The ratio as dry volume is approximately:
- 2 parts of vermiculite, i.e. 2 cups of vermiculite
- 1 part of rice flour, i.e. 1 cup of rice flour
- 1 part of water, i.e. 1 cup of water
Keep in mind you do NOT want to fill our jars completely with substrate.
You'll want to mix the vermiculite and water first. Make sure that the vermiculite has soaked up all of the water it can before adding the brown rice. Then add the brown rice flour to the hydrated vermiculite. The flour should stick to the outside surface of the vermiculite. There should be no water in the bottom of your mixing bowl after thoroughly stirring.
Fill the jars up to 10-15mm (about half-inch) below the rim. Do not compress the mixture into the jars. We want there to be air spaces through which the mushroom mycelium will be able to grow.
Wipe the top of the jars clean (inside and out) with a clean paper towel in order to ensure there is no substrate sticking on the edges. We want nothing nutritious to be left behind
Fill the remaining space inside the jar with dry vermiculite. This will serve as a contamination barrier.
Close with the lids. The lids should have 4 holes near the edges and cover the holes with masking-tape or micropore tape. The holes will be used to inoculate the jars with spore siringe.
Cover the jars with aluminium foil so that condensation in the pressure cooker won't drip on the lids and through the holes. That might cause too much water to enter the jars.
Step 2. Sterilization
IMPORTANT: put a steaming rack, or a cloth in the cooking pot or pressure cooker before putting the jars. This will avoid direct contact of the glass jars with the bottom of the cooking pot, which might otherwise cause the jars to crack.
Sterilizing with steam
This method works with brown rice flour because it sterilizes more easily at lower temperatures than other spawn substrates.
Boil 300-600ml (half-pint to a pint) jars for 60-75 minutes. Shorter times might work with smaller jars. Keep the water simmering. A vigorous boil is unnecessary as water does not heat above 100ºC (212ºF), and will risk overflow or splashing.
When you are done sterilizing let your jars cool in the cooking pot as it will protect them from contaminants. Some growers recommend to wrap the pot in a cloth soaked in sterilizing alcohol to filter the ambient air that enters the pot as it cools down, but others find this step unnecessary.
Sterilizing with a pressure cooker
The temperature in pressure cooker can reach up to 120ºC (250ºF) when the pressure reaches 15psi. Pressure cookers working at a lower pressure will reach lower temperatures.
Pressure cooking is recommended over boiling to sterilize the substrate.
With 300-600ml (1/2 pint to 1 pint) jars, 50-65 minutes at 15 psi is perfect. User longer times for bigger jars.
Once the pressure cooker has reached the maximum pressure keep the lowest flame possible to keep it at regime. This mimimize the risk of burning the substrate, internal splashing, etc.
Before starting consult the instructions provided by the pressure cooker manufacturer for safe use.
Step 3. Inoculation
The worst enemy of the mycologist can not be seen by the naked eye. Microscopic spores and endospores, as well as bacteria, can, and will, contaminate your project unless you take sterilization seriously. Always wait for the jars to cool fully, otherwise, you may just be killing the spores as you inject them. Clean your area where you are going to inoculate your jars very well, then sterilize the area. Wipe all surfaces with alcohol, dilute bleach, or ammonia. (Do not mix ammonia and bleach, as it gives off chlorine gas which was used to great effect in world war 1) Sterilize whatever surgical gloves you may be wearing. (If you use alcohol, make sure you keep it away from open flame, especially if you use it to sterilize your PLASTIC gloves.
Try to don a surgical mask, but if you can't find one, use some kind of protection to not breathe on your project. Ignite a beer cap of alcohol to sterilize the needle of your spore syringe in flame. Don't get the needle too hot near the plastic, but otherwise, bake the needle until it starts to glow. This kills any contaminants that could be inside the needle. After sterilizing with a flame, squirt a little bit of fluid out of the syringe prior to inserting to cool the needle down. Insert needle into all four holes made around the lid of your jars before sterilization. Inject 1/4 cc or more into every location as close as possible to the glass so you can track its progress in colonizing.
The other way of inoculating a substrate is to use some previously colonized substrate to colonize new, sterile substrate. When doing this, sterilization is key. Break up your previously colonized substrate very well. Take jars one at a time out of your sterilization vessel.Take a sterile spoon and spoon out 1/10 of a pint of colonized substrate into your fresh, sterile substrate. Cap the jars again as quickly as possible because exposure to open air is the biggest danger of contamination. When done right, and mixed well 1 jar can colonize 10 jars about twice as fast as using spores.
Step 4. Incubation
After inoculation, place jars in a dark, warm place. Depending on the strain, most cubensis likes to incubate at approximately 26-28ºC (80-83ºF). Any temperature above 23ºC (74ºF) is acceptable though, and you have to find what temperatures your particular strain likes. Your jars are not done incubating until they are totally covered and permeated with mycelium. Mycelium should always be white cottony to white stringy. Mycelia may turn blue in some instances, but usually only when bruised. If you see anything but white mycelium, you may want to quarantine that particular jar, or throw it away completely. Once jars are totally colonized, you may move to the fruiting, or you may use 12 jars to make 120 jars!!
Step 5. Birthing
With the PF tek, your BRF (Brown rice flour) cakes will compact a little bit. And if you used widemouth jars like you're supposed to, the cake will slide right out with a couple taps on the bottom of the jar. If you screwed up and used the wrong jars, think about using this substrate to colonize more substrate, or a straw log.
Step 6. Fruiting
The fruiting chamber should have light, but the intensity of light does not matter. Mushrooms only need the light to tell the organism to quit making roots (Myeclium) and start making mushrooms. The humidity has to stay above 90% for optimum growth, and the temperature should be approximately between 21-23ºC (70-74ºF). Temps as low as 20ºC (68ºF) can work, and there has even been evidence that cold shocking your cakes for a few hours at approximately 17-20ºC (64-68ºF) right when you birth them may put mushroom production into greater effect. Make sure your cakes don't sit directly in water, as this will invite contaminants and kill the cake, and also make sure no water drips or stands on the cake. Any terarrium, aquarium, or tupperware container can be used, and only a small amount of light is needed. The easiest terarrium is a tupperware container with 20mm (3/4 inch) of perlite in the bottom. Soak the perlite in 96% water and 4% hydrogen peroxide. All you have to do is keep the perlite wet and it will wick moisture into the container. You can use a cake pan to keep your cakes up off the perlite. Make two SMALL openings in the side of the container so CO2 can escape. These holes should be no bigger than 5mm (1/8 inch) in four places right above the layer of perlite.
Some criticisms of the method include lower yields, lower potencies, and too much labor necessary for the construction of equipment compared to other techniques such as "monotub".