How to Teach Your Friends How to Grow Mushrooms

Written By Brian Broom-Peltz

Photo credit: reddit.com/r/unclebens

Welcome to the world of mushroom cultivation!

This guide provides an easy-to-follow guide for teaching your friends how to grow their own mushrooms using a simple and scalable method. Whether it’s for culinary adventures, a fun hobby, or fostering self-sufficiency, growing mushrooms is a rewarding experience.

In this workshop, you’ll learn how to:

  1. Summarize the basics of how mushrooms grow

  2. Source the necessary supplies to grow mushrooms

  3. Grow mushrooms using the unmodified ready rice shoebox technique

  4. Create the perfect conditions for fruiting

  5. Harvest and process mushrooms for future enjoyment

By the end, you’ll have all the tools and knowledge to successfully teach others the art of mushroom cultivation. Let’s grow together!

Note: treat this guide as a starting point.  Go try for yourself and use other online resources to help fill in the gaps (and potential errors) from this workshop.  At the bottom, we link to other resources we recommend. 

For much more info and an excellent video walk through course, visit mycorising.com

For an excellent step-by-step process, visit reddit.com/r/unclebens

Introduction

Why Are We Learning to Teach Our Friends?

Our goal is to ensure that the knowledge of how to grow mushrooms is well shared.  By the end of this workshop you will become a spore capable of sharing your knowledge with friends who may want to learn more about growing mushrooms themselves; and if you then teach them — the knowledge will continue to spread.   This process means more people will have safe and reliable access to mushrooms 

The follow-up workshop: how to use mushrooms with your friends is an important part of the process as well.  Stay tuned for upcoming workshops – or just use the internet. Basic tips: start slow and go slow; be mindful of your mindset (intention, mental state, etc.) and setting (where, when, company, etc.); if it isn’t a good time - don’t do it; if you’re having a difficult time - find a comfy place and connect with a trusted buddy to ride it out - also just say yes to whatever is coming up - resistance persists, letting go flows.

Mushroom Growing 101

Photo credit: reddit.com/r/unclebens

A mushroom is the “fruiting body” of a living organism - fungus - that spreads out over a food source (aka. substrate) such as grain, decaying wood, or digested cellulose (e.g. horse poop from hay). To grow mushrooms, we need to introduce the spores (sorta like mushroom seeds) to a material they can happily grow in and maintain conditions that make it easy for them to grow without getting contaminated by other organisms like mold and bacteria that also enjoy growing in that fertile environment.  The material that spreads around the substrate is called mycelium. 

To do that, we will mix the spores in a sterilized (i.e. all organisms cooked off with heat and pressure) substrate and protect them as they begin to grow - this step is called inoculating. After they have grown a bit, they can fight off other organisms on their own.   Since 90% of the weight of a mushroom is water, to increase our yields, we can use our inoculated substrate to colonize more sterilized substrate and faster (and safer since we can catch contamination early) than if we had just introduced spores to the large amount of substrate.

After that new larger amount of bulk substrate is colonized, we will let that sit for a few weeks until it starts to sprout a flush of ‘lil mushies.  Pluck the mushroom fruits when they are ready - when depends on the type of mushroom - and enjoy fresh, cooked, or dried.  You can try to get a second flush of mushrooms by rehydrating the substrate.  For extra credit, you can also try to harvest the spores from the mushrooms to start the process from the beginning yourself. Alt

Summary of the Process

We will borrow from the /r/unclebens method of using a pre-cooked rice bag to start the process and then transfer the inoculated rice to a monotub with bulk substrate for fruiting.  This process eliminates some sources of contamination for beginner cultivators. 

1. Inoculate Rice Inject spores into pre-cooked rice bags.

2. Colonize Allow mycelium to grow in the rice.

3. Mix with Substrate Combine colonized rice with a bulk substrate in a monotub

4. Fruiting Conditions. Maintain humidity and airflow for mushroom growth.

5. Harvest Pluck mushrooms from the substrate.  Dry for long-term storage.

Materials Needed

Most of the materials can be found at local grocery and home good stores or online.  Mushroom spores can take a bit extra effort to locate depending on what you hope to grow. 

Upfront cost ~$150 Material cost per grow ~$50

Yield per grow ~350g wet > ~35g dry  (Note: that’s only for the first flush - it is possible to have multiple harvests)

Sites for materials:

Sourcing Spores

Photo credit: reddit.com/r/unclebens

In January 2024, the DEA confirmed that mushroom spores are federally legal to possess prior to germination - as long as they do not contain psilocybin or psilocin.  Spore syringes are purchased for “research purposes only” – say it with me:  we are purchasing these for research purposes to look at them under a microscopic examination because we are curious scientific people.  That said - certain mushroom spores are not legal in all states – California being a notable example ☹️

CAUTION: If you tell your vendor that you plan to grow mushrooms, vendors will cancel your order and ban you from future purchases.

Liquid culture is in a gray legal area - it is basically mycelium growing in a liquid broth instead of on a solid substrate. But since it does not contain any controlled substances, it is considered legal to possess.  [NOTE: We don’t know if possession of liquid culture has ever been used as evidence for intent to cultivate - open to hearing research on this.]

Online vendors - syringe should cost ~$20-$25 before shipping.  One 10ml syringe can be used to inoculate 10-20 bags of ready rice or ~10 quart-sized jars. 

Different strains:  Different strains have different potencies but produce the same psychoactive compounds. Good for beginners: B+, Golden Teachers. 

Step-by-Step Instructions

Phase 1: Inoculation of Rice Bags

  • Sterilize & Inoculate

  • Wipe the bag with alcohol. Inject spore solution. Seal with micropore tape.

  • Store for Colonization

  • Place in a warm (70-75°F/21-24°C), dark area for 2-4 weeks.

Photo credit: reddit.com/r/unclebens

Clean your space

The most challenging part of the process is keeping your area clean. And eventually if you work with mushrooms – you’ll end up getting your batch contaminated.  We can only reduce the likelihood. 

  • Use a clean and sterile space for working.  Hard non-porous surfaces away from carpets. 

  • Bathrooms work well. Clean bathroom super well then put on a hot shower for a 5 minutes to steam the room. Turn off vent.  Stop shower and let the mist fall - this will grab anything out of the air. Wait at least 15 minutes before you begin.  You can also use this as a chance to clean yourself and take a shower. 

  • Clean yourself - take a shower, wear clean clothes, tie back long hair. 

  • Sanitize all work surfaces, equipment and supplies with 70% isopropyl alcohol.

  • Ensure air in room is clean by closing off windows or air vents or fans for 15 min - spray with sanitizing (e.g. lysol optional) spray. 

  • Wear a mask and gloves. Replace or sanitize gloves with 70% isopropyl alcohol. 

This is what it can look like if your batch gets contaminated. If you start to see green / black — toss ASAP. Beyond just being unhealthy to breath, the spores can spread through your house and contaminate future batches.

Photo credit: reddit.com/r/unclebens

Prepping Ready Rice Bags

Pre-cooked grain or rice (e.g. Uncle Ben’s Ready Rice) is a popular option since it is sterile, shelf-stable, and 

You’ll want 2 bags per tub.  But maybe do 3 in case one goes sideways.  Don’t buy any with spices. Ideally with a clear bottom window. 

  • Use sterile procedures to put the syringe on the spore plunger. 

  • Sterilize the bag with 70% isopropyl alcohol and clean wipes. 

  • Use a lighter to sterilize the needle. 10 seconds of hot. 10 seconds to cool.

  • Poke 5x holes in a cluster in the top of the bag.  Immediately cover the holes with 2x layers of micropore tape.

  • Massage the bag to break up the rice that may have solidified during shipping. Pack by gently dropping on table. 

  • Before injecting spores, make sure the spores are well distributed. 

    • Thoroughly tap the syringe before injecting.  

    • Try holding next to an electric toothbrush to agitate. 

  • Sterilize the needle again. Poke bag near the middle and aim down at the grain. Seal with tape. 

  • After injecting into the bag:

    • If you are using spores, don’t mix the bag since the spores need to meet up with each other to start growing.

    • If you are using liquid culture, you can mix the bag and help distribute the mycelium around the substrate to begin growing. 

  • Label bag with date and culture

The images below are what it would look like if you were working with bulk grain. It is identical to using uncle ben’s ready rice - but you can see through glass.  

Waiting for colonization. 

  • Store in a happy place 75-85 (80F is ideal).  Too low - grow is slow. Too high - greater risk of contamination. 

  • Temperature: try a space heater in a closet with a thermometer to track the heater. Alternatively use the water heater in a larger tub or a cooler.  Note if you use a cooler, you’ll need to make sure it gets some daily light. 

  • Keep out of direct sunlight. 

  • Check progress in ~10 days by squeezing the bag. 

    • If mycelium is on 25% of the rice, you can break it up to distribute and help it finish faster. 

    • When done, it should all be firm. 

Phase 2: Expanding Rice to Shoe Boxes

Note: start this phase AFTER rice bags are fully colonized (completely white with mycelium).

Supplies:

  • Colonized rice bags (2)

  • 155 g coconut coir

  • 1 Tbsp gypsum

  • 6 qt showbox container. Optional: double tubs for better thermal insulation. 

  • Kitchen scale

  • 736 g boiling water

Preparing the substrate and tub

Making your own substrate with coconut coir

  • Separate the coir with a flathead screwdriver along the direction of pack. Measure out 155 g into the tub. 

  • Pour 736 g boiling water and mix with sterilized utensils. Alternative: heat in a pressure cooker for 60-90 minutes.

  • Add and mix 1 Tbsp gypsum with sterilized utensil

  • Note: “Field Capacity” or getting the right amount of water

  • Aiming for 4.75 water to 1 part coconut coir. 

  • Check by grabbing a handful and squeeze out - only a few drops should fall out

  • Cool the coir overnight: 6-24hrs;. 

Using a pre-pasturized substate

  • Buy a pre-pasturized substrate bag and add it to a sterilized tub

  • This costs more $$ but is slightly easier

Inoculating the Tub

  • If you pasteurized the substrate yourself, check the temperature of the tub has cooled down by touch.  Too hot will kill the mycelium. Looking for ~80F. 

  • Prep the space (sterilize and still air) and prep colonized rice bags (be hygienic)

  • Mix rice into the coconut coir. Flatten surface (not compress). Cover with lid quickly. 

Colonization Conditions

  • Storage: Store tub where you kept rice - 80F dark

  • Light: Mushrooms need a little bit of light a few hrs a day. Few LEDs for 2-3 hrs per day. Ambient (not direct) light from the window is good. 

  • Crack the lid: After ~10 days you may see the mycelium on the whole tub.  Crack the lid to create a tiny air gap and replace the lid. 

  • Moisture:

    • If it gets too dry (especially in a dry zone) - if you can mist with a spray bottle. 

      • Proper misting technique - mist onto the sideways and inside of the lid – only a few sprays at a time.  Don’t spray the cake directly or on the mushrooms. 

      • Mushrooms can absorb excess moisture and lead to contamination.  Avoid misting directly.  Indirect misting is usually fine. 

    • If too wet - use the corner of a paper towel to mop up liquid. 

  • If mushrooms are growing too tall - add a second inverted tub on top to give them room to grow without folding over

Phase 3 - Fruiting Harvesting and Preservation

When to harvest?

Look for pinning (tiny mushroom buds) within 1-3 weeks. Mushrooms can grow rapidly after initial pinning and ready to harvest in 5-10 days. 

The veil is almost about to break off - not after.  The mushrooms are more robust (will survive the drying process better) and are more potent.  Spores on the cake will likely prevent more mushrooms from growing in that area on a second flush. 

How to Harvest

  1. Twist and Pull

  • Gentle squeeze and twist generally will remove mushroom from the mycelial cake. Use a knife to cut off excess cake. 

  • Can risk damaging cake

  • If you can’t twist and pull without damaging the cake (leaving a crater) try cutting

  1. Cutting 

  • Get as close to the base of the mushroom with a knife. 

  • Risk: base can become a contamination vector for mold

Storage

Fresh

  • Fresh mushrooms can last in the fridge for ~1 week.  

  • Note for dosing: it is 10x what you might use for dried mushrooms since water makes up 90% of the mass of a mushroom.  So if you wanted a mild 1 gram test of your batch, you would eat 10g wet mushroom. 

Dried

  • Cracker dry: use dehydrator (if you can control temp use 150F - to ensure all the enzymes that could break down the psilocybin are denatured); or put on mesh in front of a fan to dry a bunch and then put in oven at lowest temp to finish; mushrooms will snap when done or mass will be 10% of wet..

  • Keep in a freezer bag with a silica pouch and then put that bag inside a mason jar or another freezer bag with a silica pouch. 

Continued Maintenance

  • Remove any immature pins or mushrooms. Flip cake and remove anything from the bottom. Use a knife. 

  • Heavily mist the cake avoiding puddles. 

  • Return tub to normal fruiting conditions. 

  • Subsequent flushes will be smaller - and multiple flushes risk increasing 

  • Monitor contamination and toss ASAP

  • Bury the finished cake in your garden. Who knows – maybe it will sprout there too. 

Making a Spore Print

  • If you want to use for future batches, use sterile techniques on aluminum foil (sterile, non-porous)

  • If you just want to make art - light paper works well. 

  • Best time - after veil has opened (typically later than when you might want to for normal harvesting)

  • Materials

  • Square of foil slightly larger than cap

  • 2nd larger square of foil to wrap around the first

  • Bowl or container to prevent air flow (larger is better)

Tips

Contamination

If your batch gets contaminated - toss in the garden or outside trash ASAP.  The spores can get in the air of your house and contaminate future efforts!

Resources

Brian Broom-Peltz
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