Nan's Nook : Archives : Misc Teks

PF-Tek for Simple Minds

for the cultivation of grain - loving mushrooms

updated: 26. September 2002

The PF-Tek was first made public in 1992 by Psylocybe Fanaticus. This tek made the growing of mushrooms at home feasible for complete beginners utilizing commonly available materials.
The growing method presented here is based on the PF-tek but includes a few modifications that are time tested, and are, as I think, superior to the original PF-tek.
I strongly recommend you to read the PF-Tek, if you haven´t done so already, to see a different approach to some steps.

The tek presented here uses ˝ pint (236ml) canning jars or drinking glasses and a substrate made of vermiculite, rice flour and water. The substrate is mixed, sterilized and inoculated with mushroom spores. After the substrate is fully colonized the fruiting takes place in a plastic container.

On the subject of cleanliness

As soon as you cultivate mushrooms indoor on artificially prepared substrate you create conditions than not only favor the growth of the mushrooms you attempt to grow but also of an immense number of other organisms, many of them hazardous to the health.
To make sure that only the chosen mushroom is cultivated, it is of great importance to assure cleanliness in all growing related procedures.
Before work wash your hands with antibacterial soap and warm water, afterwards wipe dry rub with Lysol or isopropyl-alcohol.
Keep the rooms where you do the inoculation and fruiting dust free and clean and don´t bring in dirty clothing or shoes. Equally important is personal hygiene, dirty hair for instance is a hotbed for all kinds of unwanted microorganisms which can do much harm to your cultivation project, same with dirty hands.

MaterialsAn den Anfang
vermiculite rice flour water spore syringe jars


Vermiculite is made from a naturally occurring mineral - mica.
Crushed mica containing water is heated and expands to a volume several times greater than that of the untreated mica.
Vermiculite is able to hold several times its own weight in water and it gives the substrate an airy structure.
Vermiculite is available in several grades, the middle and the middle-fine grade are most suitable for cultivation purposes.

Online sources for vermiculite and perlite

Google search

United Kingdom:

Vermiculite is generally available in garden and hydrophonic stores, in some regions also in pet shops.

Brown rice flour (BRF)Zurück

BRF is available in health food shops either already ground, sometimes though there is only whole brown rice available.
In this case you can grind the rice either in the shop or, if this option is not available, grind your own using an electrical coffee grinder.
BRF is best kept cool and dry for prolonged periods of time, since it can easily become rancid because of the fat content of its husk.
If you are unable to find BRF you can also use whole wheat- or rye flour with similar results.
Google search

Water Zurück

Water used for the substrate preparation should have drinking water quality. If you´re not sure about it, better use bottled drinking water or mineral water.

Spore syringeZurück

A plastic syringe with needle attached containing 10cc -12cc suspension of spores in water.
The color of the suspension varies from completely translucent to slightly violet depending on the quantity of the spores in the solution.
Spores are microscopic so as long as you see at least a few specs in more or less clear water the syringe should have plenty of spores.

Available through the internet, for instance
and many more.


Jars Zurück

The jars should have a content of ˝ pint (236ml)
You can use either canning jars (Ball, Kerr...) or drinking glasses, the only requirement is that they are tapered and without shoulders, so you can slide the cake out of it in one piece once it´s colonized.

Substrate preparationAn den Anfang

For one ˝ pint jar(236 ml) you will need:

=> 140 ml vermiculite
=> 40 ml brown rice flour
=> some vermiculite to fill the jar to the top (app. 20 ml)
=> water

˝pt(pint) = 1 cup = 236ml(mililiter) = 236cc(cubic centimeter) = 1/4 qt(quart)
The cups, pints and quarts are in the US liquid measuring system.


Put the required amount of vermiculite for all the jars of one batch (for instance 6 jars: 6 x 140 ml = 840 ml ) in a bowl.

Pour water slowly over the vermiculite while stirring with a spoon.
Be careful to only put that much water in as it can be absorbed by the vermiculite.


When you tilt the bowl you should see just a little water starting coming from the vermiculite.
This is when the correct water content is achieved.

Now put the required amount of the BRF (for instance 6 x 40 ml = 240 ml) into the wet vermiculite at once and mix it in with the spoon. The goal is to coat the wet vermiculite particles with a layer of BRF.


Fill the mixture in jars ½ inch (1cm) under the top. It´s very important to fill the substrate in the jars without tapping it down at all. It should stay very airy and loose to provide optimum conditions for the growth of mycelium.
Be careful not to leave any substrate on the upper edge of the jar. If you weren't carefull enough and there are some substrate specks at the edge take a clean moist cloth and wipe the upper portion of the jar clean. Otherwise contaminants can start at those spots and work their way down into the jar.


Fill up the jar with dry vermiculite to the top.
This layer hinders airborne contaminats reaching the underlaying substrate in case they manage to come in during the inoculation.


Take a 5in(12cm) wide stripe of aluminium foil and fold it in the middle.
Put the foil over the opening of the jar as shown in the pictures.

If you´re using jars with metal lids, you can poke 4 holes at the very edge of each lid with a small nail and hammer and screw the lid on. The holes should be slightly bigger than the diameter of the syringe needle.


Fold the foil edges up and press them together so you get a nice aluminium foil lid.

Then take a piece of foil measuring 5in x 5in in and put it over the first two layers (respectively the metal lid if you´re using lids) leaving the edges of the foil reaching down, since it has to be lifted again during the inoculation.
So now you have 3 layers of foil over the opening, only the upper layer is lifted during the inoculation.


Pour approximately 1inch (2.5cm) of water into the pressure cooker, don´t put in too much water otherwise it will come into the jars and alter their water content.
Then stack the jars into the pressure cooker. The use of a rack to keep the jars from directly touching the bottom of the cooker is strongly recomended.
Put the lid on and bring the cooker to the required pressure (15 psi = 1atm over athmospheric pressure) slowly over a period of 15 minutes on a medium flame.
If you heat the cooker too fast this can cause the jars to crack.
As soon as the steam begins to escape the rocker or the vent at the top of the pressure cooker turn the heat back so only a very small, steady steam flow persists from the vent. From this point on, pressure cook for 45 minutes.
Depending on the pressure cooker model the cooking procedure works a bit different so if you´re not familiar with pressure cooking consult the instruction manual or someone who used pressure cookers before.
After 45 min take the cooker from the flame and let cool for at least 5 hours or even better over night.
If you are unable to find or buy a pressure cooker, you can also sterilize the jars using a big pot with a lid.
In this case steam the jars for 1.5 hours in a pot lid on. Use only approximately 1 inch of water at the bottom.
You might have to add some water to the pot during steaming due to evaporation.


An den Anfang

After the cooker is cold to the touch take the jars out and place them on a clean surface, have an alcohol lamp or a lighter and the spore syringe ready. Shake the spore syringe to break up the spore clumps.


To be able to shake it it´s necessary that there is a small bubble of air in the syringe.If this is not the case, then you can suck approximately 1cc of sterile air into the syringe by placing the tip of the needle into the flame and slowly pulling the plunger back.

Loosen the foil from all of the jars so it can be lifted easily when you inoculate.

Take the cover from the needle and heat it over the flame until glowing red. Let cool for a few seconds.

Take the upper foil layer off and put aside upside down.

Pierce the foil at the edge of the jar with the needle app. 1in(2.5cm) deep and inject the spore suspension towards the inner jar surface. You should see a small drop running down the inner surface of the jar towards the bottom. Each jar is inoculated on 4 equaly spaced points. You should use 1 - 1.5 ml of the spore suspension per jar so one 10ml syringe is sufficiant for 6 -10 jars.


Put the foil on again. Flame sterilize the needle again after inoculating 2 jars to prevent cross contamination just in case a jar wasn´t properly sterilized.
When all of the jars are inoculated fold the foil edges up and press them firmly together so you get a nice aluminium foil lid. Write the inoculation date and the species/strain information on the foil with an all surface felt tip pen. If you touch something other with the needle during the inoculation procedure except the inner foil surface immediately flame sterilize the tip again..


Incubation An den Anfang

The jars should be stored at 21-27°C(70-80°F), the warmer the better, but not exceeding 27°C. If you´re unable to provide these temperatures you can build an incubator. <-- Click here
Providing the jars are kept warm you should see the first sign of germination after 3-5 days as bright white specks. This is mycelium. If anything grows that is not white, for instance green, black or pink, then the jars are contaminated and their content must be discarded and your clean procedures need some improvement. After the jars are emptied and the jar is washed with detergent and hot water it can be used again.


Dependent on the temperature it takes 14-25 days for the mycelium to colonize the whole substrate. After this is accomplished store the jars at normal room tempereature, about 21°C (70°F).
Don´t expose the jars to direct sunlight, indirect sunlight or a low wattage lamp at least a few hours a day is sufficient.

Within 5-10 days (with certain mushroom strains it can however take up to 30 days) pinhead-size accumulations of mycelium should form. These so called pins represent the beginning of mushroom growth. In the following days also small mushrooms with brown heads become visible. Now it´s time to birth the cake into the fruiting container where the mushrooms can develop to maturity.
Some strains don´t easily develop pins. In this case put the colonized jar wrapped in a plastic bag in the fridge over night and birth next day, even if the cake doesn´t show pins. This cold shocking usually helps triggering pinning.

Proceed to Fruiting

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