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Simple Cubensis Growing Technique

An outstanding guide, liberally illustrated with color photographs. It details many things which aren't in the older teks.

A quick description of the procedure

A substrate consisting of brown rice flour(=ground brown rice), vermiculite, and water is sealed in ½ pint jars and sterilized in a pressure cooker. Spores are added to the substrate using a syringe full of spore solution. The spores germinate, creating a living mycelium that colonizes the entire jar full of substrate. The resulting "cakes" are removed from the jars when fully colonized, and placed in a terrarium until mushrooms begin to grow from the cakes.

Equipment for Substrate Preparation

[ Mixing Bowl ]

Mixing Bowl

Fairly large, plastic or metal mixing bowl for mixing up your substrate in.
[ Mixing Spoons ]

Mixing Spoon

A long, sturdy kitchen spoon for mixing up the substrate. A plastic or metal spoon is preferable to a wooden spoon.
[ Measuring Cups ]

Measuring Cups

In 1 Cup, ½ Cup, 1/3 Cup, and ¼ Cup Sizes, for measuring out substrate ingredients.
[ Brown Rice Flour ]

Brown Rice Flour

A flour made from long grain brown rice. An ample bag (1-2 lbs.) can be purchased from some health food stores for $3-4.00.
[ Vermiculite ]


A soft, spongy volcanic gravel used in potting soil. A good-sized (1-3 cubic feet) bag can be purchased for about $3.00 at most hardware/garden stores.

Electric Drill


Hammer and Nail

For poking holes in the metal jar lids. The drill bit or nail should be about 2 mm (3/32") thick.
[ Jars ]

½ Pint Tapered Wide Mouth Canning Jars

They must be ½ pint size and they must be tapered (sides of the jar slant outward so that the top is widest part of the jar) so that the substrate cakes can easily drop out of the jar. These can be found in grocery stores, hardware stores, and drug stores, and cost about $7.00 for a box of 12 jars.

Aluminum Foil

Enough to make a 6" by 6" (15cm by 15cm) square for each jar.
[ Pressure Cookers ]

Pressure Cooker or Pressure Canner

The larger the better. Make absolutely sure that you know how to use it, and that all seals, valves, and safety plugs are in working order. For most people this is the most difficult item to obtain. New pressure cookers start at about $30-60.00 each, and new pressure canners start at about $250-300.00 each. Pressure canners are much easier to use and hold many more jars, but can be difficult to find. Both can be found at garage sales, thrift stores, etc. Most people who are into canning will have one. This item is essential for preventing bacteria from contaminating your cakes. Wal-Mart and similar stores are good places to look for this item.

Equipment for Inoculation

[ Spore Syringe ]

Sterile Syringe of Psilocybe cubensis Spores

Available from various sources for about $10-20.00 each. See the Spore Suppliers section for a list of spore suppliers.

Equipment for Glove Box (Optional)

Large cardboard box

Preferably unused and clean, at least 12" tall and at least 16" wide by 16" deep.

Saran Wrap (Kitchen cling-wrap) or Transparent Plastic Tarp

Large enough to cover the top of the box. Cling wrap can be placed in overlapping rows if it is not as wide as the top of the box.


To hold the box together and to attach the plastic onto the box.

Pair of Dishwashing Gloves

Preferably new and unused

Equipment for Fruiting and Harvesting

Fruiting Chamber

Aquariums, camping coolers, and large plastic [Rubbermaid] storage containers are examples of suitable fruiting chambers. See Fruiting and Harvesting for a more complete description.
[ Perlite ]


Another volcanic gravel used in potting soil, perlite is white and porous. Also can be purchased for about $3.00 at most hardware/garden stores.
[ Colander ]


For draining water out of the perlite. Suitable substitutes include a piece of screen or cloth, or anything that will hold perlite but let water drain out.

Dust mask

Perlite is puffed volcanic glass. When you work with perlite, it tends to be dusty, creating a cloud of glass dust that can be harmful to the lungs, especially if you are asthmatic. Disposable dust masks can be found in hardware stores, often in the Paint section. They are very inexpensive. They can also be used to prevent breathing our germ filled air all over our your cakes and terrariums when working with them.

Equipment for Preservation

[ Desiccant ]


Desiccants are chemicals, usually sold in the form of little granular crystals, that absorb water out of the air. Anhydrous Calcium Chloride one of the more commonly sold desiccants, and can be found in hardware stores, often in the paint section. Some of the brand names are Damp-Rid, Damp-be-Gone, and Dri-Z-Air.

Food Dehydrator

The perfect tool for drying mushrooms. Make sure it's a model that can be set to run with no heat, or you may have to take it apart and manually disable the heating element.


Substrate Preparation

Make Holes in the Canning Lids

Take the lids from the ½ pint jars and use the drill or hammer and nail to poke holes in them. One centered hole per lid is sufficient, however some people prefer to use 2 or 4 holes around the rim, so they can inoculate the cake in more than one spot. This has the advantage of faster colonization of the cake, since growth starts in several places. The disadvantage is that every time the syringe needle goes into the cake, there is a slight chance for contamination. Most guides suggest using 4 holes equidistant around the rim. Make sure that the holes are not too close to the edge of the lid.
[ Jar Lids with holes ]
Jar Lids with holes

Mix Up the Substrate

Using the appropriate quantities as outlined in the table below, mix the vermiculite and brown rice flour together in the mixing bowl, using the large spoon. Add the water and mix thoroughly. This will take some patience and will probably wear out your arm a bit. If you are concerned about the purity of the tap water in your area, you may want to used bottled water rather than tap water. In most cases, though, tap water is fine. The recipe below often comes out just a bit more than what you need for the jars. Simply discard any extra substrate. Don't try to pack it into the jars, because you want the substrate to be airy and fluffy for optimal growth.

The calculator at the far right of the chart below will give a recipe for any number of jars. Enter the number of jars in the box at the top, and click the Calculate button.
<script language="JavaScript" type="text/javascript"> </script>
Jars 1 3 6 8 12
Vermiculite 1/2 cup 1 1/2 cups 3 cups 4 cups 6 cups
Flour 1/4 cup 3/4 cup 1 1/2 cups 2 cups 3 cups
Water 1/4 cup 3/4 cup 1 1/2 cups 2 cups 3 cups

Add Substrate to the Jars

Using the mixing spoon, fill each jar to within ¾" (2 cm) of the top of the jar. It is very important that the substrate mix be open and airy, not packed into the jar. Dump it in, shake any excess back into the bowl, but don't pack it down at all. Mycelium will grow best in all those little open spaces.

Seal the Jars

Carefully wipe clean the exposed inner wall of the jar and the rim. Fill to the top with clean dry vermiculite, screw on the lid and band tightly, and cover the lid with a large square of aluminum foil, to prevent water droplets from entering. Optionally, breathable tape such as cloth surgical tape, can be placed over the holes. Your jar is sealed and ready for sterilization.

[ Finished, sealed jar ]
Finished, sealed jar

Sterilizing the Jars

Place the finished jars in your pressure cooker or pressure canner, and cook them at 15psi for 45-60 minutes, according to the instructions for your pressure cooker/canner. Let the entire apparatus cool completely. Do not try to open the pressure cooker before it is cool to the touch, and do not try to speed the cooling process, as a quick change in temperature could crack the jars. Be sure to let the jars cool for several hours, because heat is often trapped in the center of the cake, even if the jar feels cool. This heat can kill your spores if you try to inoculate too soon after cooking. It’s best if you can let your jars cool overnight. The jars are now sealed containers of sterile substrate. If you have done everything correctly, they can be stored indefinitely until you are ready to use them.

Steam [Semi-]Sterilization

Since a pressure cooker can often be difficult to obtain, a common substitute used is simply boiling the jars in a pot of steaming water. The pot is filled until the water is about an inch up the side of the jars, and then a lid is put on the pot to hold the steam in. Boil for at least an hour. This method works to some degree, and I have heard of people having a 100uccess rate using it. More common, however, is that some jars will get contaminated with bacteria, since many bacteria can withstand normal boiling temperatures. I have also heard of people getting 100 ontamination using this method.

[ Jars in Canner ] [ Canner ]
Jars arranged in open
pressure canner
Pressure Canner


Cleanliness Precautions

Inoculating your jars is the main step where contamination is possible, and thus must be done in as clean of an environment as possible. If the room you’re working in is clean enough, you can get away with inoculating them in open air. The needle of the syringe, if not absolutely sterile, can carry bacteria and spores from other molds into your cake, contaminating and ruining the cake. Wash your hands and face with antibacterial soap. Wear clean clothes. Anything in the area of the syringe and jars could contaminate your cakes if it is not clean.

Glove Box (Optional)

If you’re concerned about sterility, a good way to accomplish this is to make a "glove box," an enclosed, semi-sealed box with holes for gloves to go through and a see-through top. A cheap, halfway decent one can be built for only a couple bucks worth of stuff. All you need is a large cardboard box, some tape and saran wrap to go over the top of the box, and a pair of new, unused dishwashing gloves. Tape saran wrap over the top and cut two holes big enough for your arms in the sides. Disinfect the gloves and the inside of the box with Lysol spray disinfectant. A small gate can be cut into the side of the box for getting the syringe and jars into the box, or they can be put through one of the arm holes (if you choose not to attach the gloves to the holes).

Inoculation: Cleanliness Simplified

begin carefully inoculating them with the syringe. It's a good idea to have a lighter handy as well to sterilize the needle as you go. Flame the needle until it gets very hot, then carefully squirt a little bit of spore solution (if you can spare it) to cool down the needle before sticking it in the cake. Putting a hot needle into the cake will get burnt-on rice flour all over the needle.

[ Sterilizing the needle with flame ]
Sterilizing the needle with flame

Spore Injection

Once you’re ready to inoculate, shake up the spore syringe to get as many spores as possible off the sides of the syringe and into the water. Carefully remove the cap over the syringe needle and slide the needle into one of the holes in the jar lid. Shove it all the way in, so that the needle goes into the cake itself. Gently squeeze out about .5-1.0 cc of spore solution into each jar, splitting up the amount if you inject through more than one hole. Some people suggest using an entire cc of solution per jar, however I have had great success with only .5cc each. Be careful that nothing but the jar and substrate touch the needle, and re-cap it immediately after using it to avoid contaminating the needle. Also be careful of using too much spore solution. With spore syringes it can be easy to accidentally push the plunger on the syringe too forcefully and dump out way too much solution. Once each jar is inoculated, it is ready for incubation. There is no need to put tape over the holes in the lid, because the dry vermiculite will keep out any contaminants.

[ Spore Injection ] [ Spore Injection ] [ Spore Injection ]
Spore Injection Spore Injection Spore Injection

Mycelial (Vegetative) Growth


Now the jars are incubated at about 75-85 degrees F for several weeks. If you have a room that is constantly kept in this general range, this is a good place to incubate your jars. If not, you will need to find some other source of heat to keep them in that temperature range. Be careful not to use any heat source that could cause fires; a heating pad will usually work, some people have used fish tank heaters submerged in a warm water bath. A good investment here is a thermometer that keeps track of highest and lowest temperatures, so you can see how hot or cold your cakes are getting. If they get too cold, their growth will slow considerably, and if they get too hot, they will lose water and eventually die. (They will usually die if they ever get above 95 degrees F)

Mycelial Growth

The first signs of mycelial growth should appear within 5-7 days. If none appear within two weeks, something went wrong. (Perhaps the cake was not cooled completely before inoculation, and the heat killed the spores, or the spores simply did not make it into the cake.) This type of mushroom mycelium will always be a brilliant white fuzz, often growing in ropy strands. This ropy type of growth is called rhizomorphic growth, and is a sign that the mycelium will probably fruit very well. Any other color of mold, including some less brilliantly white molds (cobweb mold, for example, is white but not so thick, and it does look a lot like cobwebs.), is a sign of contamination. A contaminated cake will not recover and, except in very rare instances, will never produce mushrooms.

[ Rhizomorphic mycelium ] [ Completely Colonized Cake ] [ Contaminated Jar ]
A colonizing cake displaying rhizomorphic mycelial growth A completely colonized cake in a 1 pint jar A cake, contaminated with a green mold, in a 1 pint jar

Fruiting (Producing Mushrooms) and Harvesting

The Fruiting Chamber (Terrarium)

Many different things can be used for a fruiting chamber, including camping coolers, aquariums, and large plastic containers (Rubbermaid brand or similar containers work great). The fruiting chamber must be at least 6-8" (15-20cm) tall, and have enough floor space for the cakes to be arranged with at least 1" (2.5cm) of free space on all sides. Spread the cakes out as much as possible so that the mushrooms have room to grow. If the chamber is much too tall or too large, it may be difficult to keep the humidity high enough. The bottom of the chamber must be able to contain water, and the lid must be somewhat airtight in order to keep the humidity inside high. Light must be able to shine into the terrarium. If you are using a cooler or non-transparent plastic container, you will need to cut a window into the top of it and seal it with some sort of transparent material so that light can get in but humidity can’t get out. For this reason, glass aquariums make very nice fruiting chambers if they are kept at the right temperature range.

[ Plastic Terrarium ] [ Plastic Terrarium ] [ Rubbermaid Terrarium ]
A plastic storage container with damp perlite layer and thermometer/hygrometer Two more terrariums made from plastic storage containers A Rubbermaid-type fruiting chamber with a screen to let light in through the top.

Birthing the Cakes Once a cake is completely covered in white mycelium, wait at least 1-2 more days before taking the cake out of the jar. When you are ready, and in a fairly clean room, begin transferring the cakes from their jars into their fruiting chamber (described in the next step). Remove the lid of each jar, and dump out the dry vermiculite on top. Then, put the lid back over the top of the jar. Slowly turn the jar upside down, so that the cake is resting on the jar lid. You may need to gently tap the jar to knock the cake loose. Take the jar off the top of the cake and then carefully pick up the cake and turn it over, so it is sitting right side up on the lid. Placing down a piece of foil, , put them it into the fruiting chamber. Once all the cakes have been transferred, you’re ready to induce fruiting.
[ Cakes in Terrarium ] [ Cakes in Terrarium ]
Cakes in terrarium seen from above Cakes in terrarium seen from the side

Inducing Fruiting (Producing Mushrooms)

In order to initiate fruiting, three main conditions must be met for the cakes:

  1. First, they need light. Only a dim light is needed. A fluorescent lamp or indirect sunlight is plenty of light. Mushrooms do not gain energy from the light like plants do, but in this particular species of mushroom light sends a signal to the mycelium that it is time to produce mushrooms. A source with a wide spectrum of light, especially containing lots of blue light (daylight and fluorescent plant lights are very good examples of light with lots of blue) is best, but a low wattage (15 watts is plenty) incandescent light bulb will supply enough light.

  2. Second, they need a fairly high humidity. 90-95umidity is a good range for fruiting. The best and easiest way to do this is by lining the bottom of the fruiting chamber with damp perlite. A common mistake is to get the perlite too wet, and end up with a swamp of water and perlite that is very difficult to clean up, and will drown the cakes. Get enough perlite to make at least 1" (2.5 cm) thick layer on the bottom of the fruiting chamber, and put it into a colander, strainer, or cloth enclosure that it can’t slip out of. Wet it thoroughly with normal tap water, and let the water drain out. Then move the perlite into the fruiting chamber and smooth out the surface. You now have a layer of damp perlite that the cakes can be set directly on, and which will keep the humidity in the chamber high enough for the cakes to fruit. By the time your cakes have stopped producing mushrooms, the perlite might start getting a little bit skunky smelling. If you want to reuse it, put it in a baking pan and cook it at 350 degrees in your oven until it is dry. Let it cool, and it’s ready to be used again. You can also add some Hydrogen Peroxide to the wet perlite to help it stay clean a bit longer.

  3. Lastly, it is a good idea to lower the temperature range a bit, to about 75-80 degrees F. Like the light, this signals the cakes to begin fruiting. However, most strains of Psilocybe cubensis fruit so easily that lowering the temperature is not absolutely necessary.

Pinning, Fruiting, and Harvesting

For the first week or two, the cakes will generally not do anything. Then, very small bumps, called "pins," "pinheads," or "primordia" will begin to grow out of the surface of the cake. These are the beginnings of mushrooms. Many will never grow any larger. However, some will grow until they are full-grown mushrooms. A mushroom is ready to be picked when the edge of the cap tears away from the "stem" (the stem of a mushroom is called the stipe). Often, there will be a thin veil between the cap and stipe. If this is present, you can wait until the veil tears before picking the mushroom. To pick a mushroom, grasp it near the base where it is joined to the cake, and gently twist it until it comes off. Immediately begin the process of preserving it, either by refrigerating it or by drying it, mushrooms will begin to rot immediately. Each cake will produce about 1-3 waves or "flushes" of mushrooms, normally with 2-5 days of dormancy between flushes. After about a month or so of fruiting, most cakes will be spent, and will not produce any more mushrooms unless rehydrated by dunking underwater for 24 hours, see dunk tek.
[ Pinheads ] [ Primordia ] [ Veil Tearing ] [ Veil Tearing ]
Close up of pinheads and primordia growing from the top of a cake A young mushroom with the edges of the cap pulled away from the stipe Veil being torn with a knife Underside of cap with veil torn away
[ Fruiting Cakes ] [ Fruiting Cakes ] [ Fruiting Cakes ] [ Fruiting Cakes ]
Two cakes beginning to grow young mushrooms Cakes with growing mushrooms and primordia Very mature mushrooms fruiting from a cake. Note the upturned edges of the cap on older mushrooms. Many cakes fruiting


Some of the pinheads will begin to grow, then suddenly stop before they become full-grown mushrooms. These are known as aborts (aborted mushrooms). Aborts are just as good for eating as full-grown mushrooms, but they must be picked before they begin to rot. A mushroom that has mold growing on it or which has black goo in the center of the stem is rotten and is not safe to eat. It is often difficult for beginners to identify an aborted mushroom before it begins to decompose. Early warning signs include a halt in growth of the mushroom, and a greenish tinge around the dark colored tip of the primordia that will eventually become the cap of the mushroom. Always completely remove aborts from the cake, even if they are too rotten to eat, because they can get moldy and cause the cake to get infected.
[ Abort ]
An abort at the base of a cake

Preservation Methods


If you will be consuming your mushrooms fairly soon after picking them, you can keep them in your refrigerator, in a paper bag. Don’t use a plastic bag to store fresh mushrooms, this will cause them to mold. Fresh mushrooms are reportedly stronger than dried ones, but can be more difficult to dose. Also, cubensis is a particularly nasty tasting species of mushroom, especially when fresh. Many people prefer to dry their mushrooms before consuming simply because drying will kill some of the bad flavor. It should also be noted that some people like the taste of cubensis, and that the flavor of cubensis can vary depending on which strain was used and under what conditions it was grown.
Drying The best way to preserve mushrooms is to dry them as soon as possible after picking. It is very important when drying that the mushrooms never be exposed to heat. Psilocybin and Psilocin, the main active chemicals in Psilocybe mushrooms, are heat-sensitive chemicals that will break down if exposed to heat. You can get away with drying them in the sun, but expect some loss in potency. Another common method of drying is to put the mushrooms in an enclosed container, like a covered bowl, that also contains some desiccant. While drying mushrooms using desiccant will dry them very thoroughly, it will also take a very long time, giving the mushrooms more time to decompose.
[ Diagram of desiccant chamber ] [ Photo of desiccant chamber ] [ Dried Cap ]
Diagram of desiccant chamber Photo of desiccant chamber A completely dried mushroom cap and stem

Another way to dry mushrooms is with the use of moving air. Simply place them in front of a fan (not a heater), and the moving air will dry them very quickly. An even easier way to air-dry mushrooms is with a food dehydrator. If the dehydrator doesn't have a switch for turning off the heat, you will need to take it apart and disconnect the heating element, making sure to take any necessary safety precautions. Air-drying is by far the fastest way to dry mushrooms, but will not always remove all of the water from the mushrooms. The drying process can be accelerated substantially by slicing the mushrooms lengthwise into halves or quarters, thus increasing the surface area of each mushroom.

The best overall method for drying mushrooms is to first dry them using moving air, then, if necessary, put them into a desiccant chamber to remove the last little bit of moisture that remains in the mushrooms. You want your mushrooms to be bone dry and brittle. If they feel flexible, they are probably not totally dry. Store the dried mushrooms in a sealed container, away from heat and light. You can make sure that they stay dry by putting some desiccant into the storage container with them. The little desiccant packets that come in vitamin bottles will work to some extent. You can also make your own desiccant packets by wrapping up about a teaspoon of desiccant granules in a paper towel and securing the packet with rubber bands or tape.


Spore Syringe and Prints Suppliers

Credits and Notes:

Where to find this document

The original version of this document can be found at the SCGT home page: http://growmushrooms.org/

Sources of information

This document is based on various techniques outlined in other documents already available on the internet, including the PF Tek and the The Magic Mushroom Growers Guide Version 3.2; It is also based on the shared experiences of those who have worked with these guides.

Image Credits

Thanks to:

The Dogg

- For the great pics of some very successful cakes:


- For the image of the spore syringe.


- For his outstanding close-ups of perlite and vermiculite:

Black Flag

- For the following awesome images:

Use of this document

This document may be freely distributed, in whole or in part in any form. This document may not be distributed for profit.

Copyright 1997-2024 Mind Media. Some rights reserved.

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