The PF-Tek MycoBag Grow Kit (v2.0)


The classic, well known PF-Tek recipe in large volume.

Just about every new mushroom grower starts with the PF-Tek method, but usually in small half-pint jars which we offer as MycoPots (and MycoJars when they are back in stock!)..  Well this bag contains as much as 4 jars worth of the same substrate for, you guessed it – bigger flushes!

An added benefit of the bag method is that it can be safely squeezed and squished to help loosen a colonising substrate to mix the growing mushroom mycelium further to boost the speed to around the same time as a much smaller half-pint sized MycoPot or MycoJar.

The trade off with with MycoBags is that it’s kind of like putting all of your eggs in one basket!  If you only purchase one kit and mess up, then it’s all ruined, but losing a single MycoPot out of three wouldn’t hurt as bad!

V2.0 / June 2019 – Now includes even more perlite and a larger humidity tent for better airflow, hydration and ease of use!

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A classic recipe of brown rice flour and vermiculite, enhanced with gypsum.

This is a newbie friendly grow kit which supports many species of non-woodloving mushrooms, such as Blue Oyster and more.

The MycoBag will arrive looking a bit like a dense cake! It’s recommended to squeeze the bag until the mixture inside becomes nice and loose.

Prior to inoculating the MycoBag, remove and dispose of the secondary outside bag – it’s not needed.  Give the injection port a quick clean with the included alcohol wipe and allow it a few seconds to dry..

Now inject 3ml of gourmet spore or liquid mycelium through the rubber injection port and wait for it to colonise.  Our grow guide explains all the rest in more detail!

  • 1L Substrate for a huge mushroom  yield
  • Organic Brown Rice Flour Substrate with added Vermiculite and Gypsum
  • Injection Port and HEPA-Filtered for ultimate contamination resistance
  • HEPA-Filtered Humidity Tent(s) for each MycoBag
  • Hygiene Kit includes sterile gloves, face mask, alcohol wipes and hand wipes
  • Perlite to create and maintain high humidity
  • Vermiculite for “Dunk n Roll” technique
  • Full Instructions (also available within our guides section)

Can take up to 4 weeks to fully colonise in optimum conditions.
Does not come supplied with a spore or culture syringe.
Most wood-loving species will not fruit well on this substrate.

Grow kits are currently only available for customers in the United Kingdom.
Product is made fresh to order – please allow for a 1-3 day dispatch time.
Only for use in cultivating species which are legal to grow – research the law.

Grow Guide


You will need:

  • Your chosen gourmet spores or liquid mycelium syringe
  • PF-Tek MycoBag(s)
  • A lighter to sterilise the needle (Only needed if working with multiple MycoBags and haven't purchased extra sterile-packed needles)
  • Sterile gloves (as supplied with kit)
  • Face Mask (as supplied with kit)

With this product, it's unnecessary to work within a Still-Air-Box (SAB) or any other purpose built clean room environment - although it certainly won't do any harm!


1. Take everything to your 'lab'

An ideal room to use as your lab will be draft-free, such as a small cupboard maybe. Kitchens and bathrooms are generally not suitable because of the increased risk of mould - but the fitted injection port and HEPA-filter on the MycoBag(s) should still protect you in any case.

Take everything you will need into your lab at this point - keep air currents to an absolute minimum (doors closed!) to lower the odds of a contaminant spore dropping onto the self-healing injection port directly prior to syringe inoculation of gourmet spores or liquid mycelium!

Remove the MycoBag(s) from the box so that you can later grab them with ease.

2. Cleanliness

Take the time to ensure you are completely clean - have a shower, brush your teeth and change into fresh clothes.
Before you begin the inoculation process, take your face mask out of the bag and secure it tightly to your face. Then, make sure your hands and forearms are clean - you can wipe them with the included Clinell wipes and let them completely air dry first or you'll struggle to put your sterile gloves on!

3. Inoculation process

When you are ready and have fitted the pre-sterile needle on to the syringe, open the alcohol wipe and thoroughly wipe the injection port and give it a few seconds to dry before swiftly piercing your needle through the self-healing injection port and inject approximately 3ml in a circular motion.

If you are inoculating more MycoBags with the same syringe, make sure to flame sterilise the needle until it is glowing red hot between MycoBags. This will reduce any chances of cross contamination. Just remember to leave the needle to cool down for 5 - 10 seconds, or you can just squirt a little solution through it to cool it quicker!

DO NOT EVER wipe a needle with an alcohol pad. Alcohol merely sanitises, it does not sterilise. Flame sterilise for fast results.

4. Air exchange, light and room temperature

Now it's time to leave your MycoBag(s) in a safe place to colonise. Unfold and open out the top of the bag so it can breath from it's HEPA-filter. If you need to pull apart the stcu plastic sides to help the process, this would be good. It is recommended, although not necessary, to leave colonising substrates in a room with indirect sunlight or light from a flourescent bulb.. but many growers just leave them in a dark cupboard - so don't worry about that too much. Just make sure the sun isn't beating down on them!

Regarding heat, many species do love very warm climates during colonisation but it can be a balancing act because so do bacteria!

If your mycelium is going strong, it can outrun many types of bacteria and you will never know they were even present..

If you can manage to keep the colonising MycoBag(s) somewhere between 18C and 26C, then it will be just fine. 26C is noticeably faster than 18C, but if you have a cold house or flat don't worry about it - it will do it's job! I have even managed it in a cold 10C flat! If you are determined to get a warmer environment for faster colonisation times, I'd strongly advise against heat mats as they will just dry out the bottom of your substrate. You will need something a bit more equal on all sides. A warm cupboard above a fridge.. Near the water boiler..?

5. Colonisation

Generally, you will start to see mycelium growth after 5-10 days, but because we are injecting into the center of the MycoBag(s) - this may take longer to show, but when it does you can be sure it's just about finished!

It will normally take around 5-8 weeks for your MycoBag(s) to fully colonise (i.e. to be completely covered in white mycelium) but again, this can take a bit longer or shorter depending on a range of factors such as temperature, genetics, whether from spore or culture syringe etc..

When they have reached full colonisation, it is highly recommended that you leave them for another week to allow the mycelium to consolidate - basically, to make sure the mycelium has a full hold on the PF-Tek MycoBag cake(s).


The MycoBag(s) would be acceptable to fruit within like many other suppliers do with their grow kits, but for excellent results we will case it with vermiculite and use a completely different bag technology for the purpose of fruiting - MycO2Bag(s) provide more clean fresh air without too much water loss!

You will need:

  • Bag of fine vermiculite (supplied with kit)
  • Spray Bottle Mister with water (tap water is fine)
  • Scissors

1. Carefully clean a work surface near a sink and take your fully colonised MycoBag(s) to this area. Cut all around the bag 2cm above substrate level until removed.

2. Pour in the vermiculite until 1cm above the substrate level (between the top of substrate and top of newly cut bag).

3. Mist the vermiculite casing heavily with water until very damp before moving straight on to stage 3..


Now you are ready to grow some mushrooms!

You will need:

  • Bag of perlite (supplied with kit)
  • A sieve/strainer
  • Humidity tent(s) for each of the MycoBag(s) (supplied with kit)
  • A spray bottle to mist your casing with water

1. The first step is to rinse the perlite to get rid of all the excess dust. Please wear a face mask or cover your mouth and nose in some way when working with perlite. Get yourself a sieve or strainer (of course with holes smaller than the size of the perlite) and empty the perlite into it. Rinse under a running tap until you can see all of the dust is gone and that the perlite is fully soaked, turn the tap off and shake off some of the excess water.

2. Immediately pour all of the damp perlite into your humidity tent(s) - this will create the humid environment mushrooms love.

3. Place your cased and cut open MycoBag(s) on top of this damp perlite layer.

4. Fold over the top of the bag and either leave it as is (if the opening is pointing downwards, no dust/mould particles can fall in there) or if you prefer - you can put some paper clips or pegs on there to hold it shut.

5. You will now need to mist your cake(s) with water regularly to ensure constant hydration. Mist your casing(s) directly until they glisten with moisture and when you can no longer see the glisten on them, it's time to mist them again.. Misting 3-6 times a day is pretty common for ultimate results.

Click here to view some photos which will help you see what is meant by 'glistening with moisture'.

The evaporation of moisture from your casing(s) is the trigger for mushroom pins to form and grow - this is why the humidity tent(s) we supply in our grow kit have lots of filters to provide clean air exchange. If you do not mist regularly to replace this evaporating moisture, you will break the cycle and you will have a very bad harvest.. Simple as that.

You must continue to mist throughout the full growing process - when you see pins forming and whilst your mushrooms are growing.. remember mushrooms are 90% water, they need all that extra moisture!!


When your mushrooms are ready for harvest, you can either cut them off your with a knife/scissors or some people prefer to just twist and pull their mushrooms off!

...Have fun and enjoy the fruits of your labour!