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Materials Needed

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.

Brown rice flour. Commonly referred to as by its acronym, BRF, brown rice flour is a hyper-nutritious substrate that will provide nutrients to our mushroom.

Mason jars. We'll be using wide-mouthed half pint (~240ml) 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.

The Guide

Step 1. Preparing the Jars

In order to construct the substrate, we will be mixing some brown rice flour and vermiculite together with purified water. The ratio we are looking for is 2:1:1,vermiculite:brown rice flour:water. If we were making 12 half pint jars, we'd need about 12 cups of substrate. That would mean that we need 6 cups of vermiculite, 3 cups of brown rice flour and 3 cups of purified water.

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 up the jars up to a 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.

After the jars are filled a half inch from the tops use a clean paper towel to wipe the top of the jars (inside and out) in order to ensure they are clean. This half inch area will serve as a contamination barrier so we want nothing nutritious to be left behind. Finally, fill that last half inch of each jar with dry vermiculite and put the top on with 4 holes near the edges (to insert needle in after sterilization. Cover the holes with pro-grade masking tape or micro spore tape. You can add the Al foil top at this time.

Step 2. Sterilization

With brown rice flour as our substrate, we have two options for sterilization, a pressure cooker or steaming.

Sterilizing with steam

Since brown rice flour sterilizes more easily at lower temperatures than other spawn substrates, we can perform sterilization with a boiling pot of water.. With half-pint and pint jars, 60-75 minutes is plenty. Get the water to a GENTLE boil. Higher heat will only cause overflow of your pot, as water does not heat above 212 degrees, and allow to boil for 60-75 minutes. Add a wash rag or piece of cloth to the bottom of the pot before putting your jars in to sterilize them. This will be a buffer so that excess heat won't transfer straight from the metal of the pot to your glass. Wrap the top in tin foil to cover the 4 holes. When you are done sterilizing, it is always a good idea to let your jars cool in whatever vessel you sterilized them in, as this is the cleanest environment possible, and when the air in the jars and pot gets colder, it will contract, and suck in a small amount of ambient air, and when that happens, you want any air that may go in to be as clean as possible.

Sterilizing with a pressure cooker

When sterilizing with a pressure cooker, higher heats are used, up to 15 psi and 250 degrees. When sterilizing with a pressure cooker, add a wash rag or cloth to the bottom of the pressure cooker to act as a heat buffer between your jars and your pressure cooker. You do not want heat to transfer directly from the metal to the glass jars as this may dry your substrate out. With half-pint and pint jars, 50-65 minutes at 15 psi is perfect. With quart jars, 65-75 minutes may be advisable. Whenever the pressure in your pressure cooker gets high enough to leak, it is hot enough, and maintain just a tiny amount of steam coming out of your pressure check valve. You do NOT need to have it going full blast and blowing steam out. I have done this, and it either carmellizes the sugar, or dries it, but excess heat can once again screw up your project. For Guaranteed contaminant free growing, you really need a pressure cooker.


There is no point in fractional sterilization with a pressure cooker. If you are sterilizing grains for spawn to colonize bulk substrate, there may be some benefit to fractional sterilization. This is a tek for brown rice flour, vermiculite, and distilled water, but anyone reading this should look into grains, such as bird seed, popcorn, rye berries, etc... These substrates break up easily, and can be used to colonize substrate on a bulk scale. 12 pints of colonized rye berries is enough to colonize a 40 lb. mushroom cake in a laundry basket!@!

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 innoculate 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 flame, wipe the needle with 70% or better alcohol immediately before inserting the needle into your jars. 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 innoculating 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 innoculation, place jars in a dark, warm place. Depending on the strain, most cubensis likes to incubate at 80-83 degrees. Any temperature above 74 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 shrink 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 temperatur should be fro 70-74. Temps as low as 68 can work, and there has even been evidence that cold shocking your cakes for a few hours at 64-68 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 easies terarrium is a tupperware container with 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 1/8 inch in four places right above the layer of perlite.

Criticisms

Some criticisms of the method include lower yields, lower potencies, and too much labor necessary for the construction of equipment.

See Also

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