Introduction to PF Tek

Developed by Robert McPherson (a.k.a. Psilocybe Fanaticus) in the 1990s, PF Tek quickly became the most accessible mushroom-growing method for beginners. It’s simple, low-tech, and reliable — everything you need to learn the fundamentals of mushroom cultivation without expensive lab equipment.

At Kai Kai Farm, we use the same PF Tek principles in our own production systems and teach them to home growers who want to start clean, small, and successful. The method uses brown rice flour (BRF), vermiculite, and water — three ingredients that provide food, moisture, and structure for mycelium to grow inside sterilised glass jars.

Once fully colonised, each jar is turned out as a "cake" and placed in a humid fruiting chamber. With good care, a single cake can yield multiple flushes of gourmet mushrooms — oyster, lion's mane, shiitake, and more.

What You Will Need

Most materials are inexpensive and easy to find — and we’ve linked the essentials from our store below.

Ingredients & Supplies

  • Brown Rice Flour – the food source for your mycelium
  • Vermiculite – keeps the mix light and evenly moist
  • Clean water – filtered or boiled and cooled
  • 2-4 250-500ml glass jars with lids (ideally wide-mouth but regular will work)
  • Micropore tape (polyfill or stuffing material can be used as a substitute)
  • Spore syringe, liquid culture or gran spawn (choose your gourmet or medicinal species)
  • Aluminium foil
  • Large pot or pressure cooker for sterilising
  • Still-air box or clean area for inoculation

→ Try our Kai Kai Farm Vermiculite and Organic Brown Rice Flour — the same materials we use on the farm for consistent results.

SHOP ORGANIC BROWN RICE FLOUR

Modify Jar Lids

You need to make a few holes in the lids so there can be air exchange. Either drill with a 6mm bit or use a hammer and nail.

Hint, use a block of wood underneath the lid as a solid surface so the lid doesn't bend or distort when making holes.

These holes will be covered with micropore tape once mushroom culture or spawn is added to ensure the contents remain clean.

1 4

Vermiculite Fine Grade – Ideal for Mushroom Substrate/Seed Starting

$7.00
$7.00
Sale Sold out
Taxes included. Shipping calculated at checkout.
Size
View full details

PF Tek Recipes

Original PF Tek Receipe (2:1:1 Mix)
250mL Jar Vermiculite (2 parts)Brown Rice Flour (1 part) Water (1 part)
1 jar125 ml (½ cup)62 ml (¼ cup)62 ml (¼ cup)
2 jars250 ml (1 cup)125ml (½ cup)125ml (½ cup)
4 jars500 ml (2 cups)250 ml (1 cup)250 ml (1 cup)

Enriched PF Tek Recipe (1:2:2 Mix)
250mL Jar Vermiculite (1 parts)Brown Rice Flour (2 part) Water (2 part)
1 jar50 ml100 ml100 ml
2 jars100 ml200ml200ml
4 jars200 ml400 ml400 ml

Step-by-Step PF Tek Process 1/2

  • 1. Gather Your Materials

  • 2. Mix Your Substrate

    Combine in a bowl: 

    • 2 parts vermiculite
    • 1 part water


    Mix gently until evenly moist — not soggy. When you squeeze a handful, only a few drops should come out.


    Add half of the brown rice flour and mix well, then add the other half and mix again.

  • 3. Load Your Jars:

    Spoon the mix loosely into each jar, leaving 2 cm of space at the top.


    Wipe the rim clean, then fill the top with dry vermiculite (this acts as a contamination barrier).


    Cover with the lid, add a layer of foil, and they’re ready for sterilisation.

  • 4. Load Up Your Pot

    Add about 25mm of water to a pot with a stand to keep the bottles off the bottom of the pot.


    Add the jars into the pot ensuring the aluminium foil fits tightly around the lids.

1 4

Step-by-Step PF Tek Process 2/2

  • 5. Sterilise or Steam

    Steam the jars for 60–90 minutes (or pressure-cook for 45 minutes at 15 psi).

    Allow to cool completely before the next step.

  • 6. Innoculate:

    Working in a clean space, shake your spore syringe or liquid culture and inject through small holes in the lid — usually four per jar, around the edge.

    Alternatively you can use grain spawn and aim to cover the surface, this has the added benefit of extra nutrients.

    Wipe the holes and seal with micropore tape.

  • 7. Incubate:

    Store jars at 22–26 °C in a clean, dark place.

    Over 2–3 weeks you’ll see white mycelium spreading through the substrate.

    Wait until each jar is fully white before moving on.

  • 8. Birth and Fruit:

    Remove the jar lid, tap the “cake” out, and rinse gently under water.

    Place on foil inside a humid fruiting chamber (a clear tub with moist perlite works well).

    Mist and fan 1–2 times a day. Within a week or two, you’ll see tiny pins forming — soon to become full-grown mushrooms!

1 4
  • Brown Rice Flour (Organic BRF) for PF TEK Kai Kai Farm
1 2

Organic Brown Rice Flour (BRF) for PF TEK

$5.00
$5.00
Sale Sold out
Taxes included. Shipping calculated at checkout.
Size
View full details

Common Mistakes to Avoid

These four errors cause the vast majority of failed PF Tek grows. Avoid them and your success rate will be high.

  • Rushing incubation: Wait until full colonisation before fruiting.
  • Too wet substrate: Excess water slows growth and encourages contamination.
  • Dirty workspace: Always clean your hands, tools, and surfaces before inoculating.
  • Poor airflow: Mushrooms need oxygen — stagnant air can stunt growth.
Shop Organic BRF

Why PF Tek Still Matters?

Even after decades, PF Tek remains the foundation of modern home mushroom cultivation. It teaches the core principles of sterilisation, humidity, and patience — skills you’ll use in every grow that follows.

Plus you probably have most of the materials at hand already meaning its an easy way to try out growing mushrooms for yourself.

Once you’ve mastered PF Tek, you can easily scale up to monotubs, grain spawn, or commercial grow blocks like the ones we produce at Kai Kai Farm.

 

Shop Organic Brown Rice Flour

Optional Enhancements

  • Change up the recipe, use 1 part vercimulite : 2 parts BRF : 2 parts water for the more nutrious substrate resulting in bigger yields

  • Use a still-air box for cleaner inoculations

  • Try a liquid culture for faster colonisation

  • Upgrade to ready-to-fruit grow blocks for even bigger harvests
Shop Fine Vermiculite

Frequently Asked Questions About PF Tek

How long does PF Tek colonisation take?

PF Tek jars typically take 2–4 weeks to fully colonise at 22–26°C. Wait until every jar is completely white before moving to the fruiting stage — partial colonisation increases contamination risk significantly.

Do I need a pressure cooker for PF Tek?

No. PF Tek can be done with a regular pot and steaming at 100°C for 60–90 minutes. A pressure cooker at 15 psi for 45 minutes is faster and more reliable, but not essential for small batches. Most beginners start with stovetop steaming.

What gourmet mushrooms grow best with PF Tek?

PF Tek works well for oyster mushrooms, lion's mane, shiitake, and turkey tail — all species that colonise brown rice flour substrate reliably and fruit successfully from cakes. These are the same species we grow here at Kai Kai Farm.

Why is my PF Tek contaminated?

The most common causes: insufficient sterilisation time, inoculating before jars have fully cooled, a dirty workspace during inoculation, substrate that is too wet, or cracked/poorly sealed lids. Ensure the substrate passes the squeeze test and your workspace is as clean as possible before inoculating.

How many flushes can I get from a PF Tek cake?

A well-maintained PF Tek cake typically yields 2–4 flushes. Between flushes, rehydrate the cake by soaking it in cold water for 4–12 hours. Each subsequent flush tends to be smaller than the previous one as the substrate nutrients deplete.

Ready to grow your first flush?

PF Tek is more than just a method — it’s an invitation to connect with the fascinating world of fungi. With a few basic tools and a little patience, you’ll watch life unfold in real time, from spores to harvest.

Start small, stay curious, and enjoy every stage of the process.

Grab your vermiculite and brown rice flour from the our growing supplies along with some liquid culture or mushrooms spawn, and start your first PF Tek today.

Inline Buttons
Shop Organic Brown Rice Flour Shop Fine Vermiculite