Supplies/Materials

• Multifunctional Monotub (Includes Still Air Box)
• 2x Large Mason Jars
• 2x Small Mason Jars with Injection Ports
• 10ml Golden Teacher Spore Syringe
• 70% Isopropyl Alcohol Disinfectant (50ml)
• Scalpel
• Micropore Tape
• Lighter
• 2 Agar-Malt Mixtures
• Black Foil (Liner)
• 300g Coco Coir
• 400g Brown Rice
• Pair of Gloves
• Sterile Mask
• 100 Drying Packs

Tools Required

• Different Sizes Cooking Pots with Lids
• Aluminum Foil
• Paper Towel
• Duct Tape
• Parchment Paper
• Bowl
• Airtight Container (for Storage)
• Colander (Optional)
• Fan (Optional)
• Dehydrator (Optional)
• Baking Rack (Optional)
• Pressure Cooker or Insta Pot (Optional)
• Scale (Optional)
• Oven or Microwave (Optional)

Instructions

1. 1.

   Understanding the Basics of Mycology

   Mushroom cultivation starts with spores – tiny “seeds” of the mushroom. Under the right conditions and nutrients, spores germinate and form a white network of threads called mycelium (think of this as the mushroom’s root system). Once you have enough mycelium, you mix it into a bulk substrate. Within days, mushrooms grow from that substrate. Those mushrooms will eventually drop new spores, continuing the cycle.
   
   However, one of the biggest challenges is contamination. Mold or bacteria are everywhere, especially floating in the air, and they can easily outcompete and kill your mycelium. To prevent contamination, always sanitize equipment, sterilize your substrates, and practice sterile techniques.
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   Careful, patient work is the key to success.

   
2. 2.

   Preparing and Sterilizing Agar Plates

   Begin by preparing nutrient-rich agar plates where your spores will germinate. First, cover the airflow holes of the small mason jars with micropore tape. This tape allows the mycelium to breathe while keeping contaminants out.
   
   Next, pour about 50 ml (1.7 fl oz) of water into a small pot and add one packet of agar-malt mixture. Stir for around 3 minutes. Bring the mixture to a boil on medium heat; once bubbles form, the agar is activated and can solidify. Turn off the heat and stir one last time.
   
   Pour the hot agar evenly into the jars and let them cool open for 5 minutes so excess water evaporates. 

   
   

   After 5 minutes, loosely seal the jars: screw the lids on fully, then unscrew slightly to regulate pressure. Cover each lid with foil to prevent extra moisture inside. To sterilize, use a steam bath: place the jars on a trivet or rack in a large pot, add about 1 liter of water (without touching the jars), cover, and bring to a boil. Reduce to medium and steam the agar for 1 hour.
   
   If you have a pressure cooker or Instant Pot, you can sterilize at 15 psi for 30 minutes or 12 psi for 45 minutes, which is even more effective. After steaming, let everything cool for at least 2 hours. Remove the jars, tighten lids, and peel off the foil.
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   Optionally, you can leave the sealed jars at room temperature a few days to confirm sterility. If nothing grows, they are sterile.

   
3. 3.

   Inoculating Agar with a Spore Syringe

   Now you inoculate your agar with a spores syringe. Put on a mask and sterilized gloves, since a clean environment is crucial for success. Spray a paper towel with 70% isopropyl alcohol and wipe down each jar’s injection port (the grey silicone part).
   
   Open your spore syringe and attach the needle. Quickly insert the needle into the middle of a jar’s injection port and inject about 0.5–1.0 ml of spores. 

   
   

    Immediately flame-sterilize the needle (using a lighter until it glows red) before going to the next jar to prevent cross-contamination. Wait a few seconds for the needle to cool, then repeat into the next jar.
   
   After inoculating all jars, gently swirl each jar to spread the spores across the agar surface for faster germination. Store the jars in a dark place at 21–27 °C (70–80 °F). In about 1 week, you should see first traces of white spots as spores germinate into mycelium. In about 2-3 weeks, the entire surface should be covered with mycelium, so you're ready for the next step.
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   Always sterilize your needle between jars and work quickly but carefully. Flame-sterilize outside the still air box (if you set one up) to avoid igniting disinfectants inside.

   
4. 4.

   Preparing and Sterilizing Grain Spawn

   Boil 800 ml (0.85 qt) of water. Meanwhile, cover mason jar holes with micropore tape as before. When water is boiling, reduce heat to medium and add the rice. Stir and boil for 10 minutes, then drain thoroughly (a colander helps). The goal is slightly cooked but firm rice. Rinse the rice with cold water to stop cooking, then shake the jars a few times to settle the rice and let it cool for about 30 minutes.
   
   Scoop the cooled rice into the jars, filling them about ¾ full. Leave some headspace for the next step (“break and shake” later). 

   
   

   Screw the lids on tightly but not fully, they should still be able to move slightly if needed, and cover them with foil. Sterilize these grain jars just like the agar: place them on a rack in a large pot with at least 2 liters of water (water should not touch jars), cover, and bring to a boil. Steam for 2 hours on medium heat, adding water if needed.
   
   Again, a pressure cooker is more efficient: sterilize at 15 psi for 1.5 hours or 12 psi for 2 hours, then cool for 6 hours. After sterilizing, cool completely, tighten the lids fully, and remove the foil.
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   Two or three rounds of steaming significantly increases chances of success.

   
5. 5.

   Transferring Mycelium from Agar to Grain

   When your agar jars are fully colonized, transfer bits of mycelium to the grain jars so the mycelium can colonize fresh nutrients. This agar-to-grain transfer is sensitive to contamination, so set up a Still Air Box (see next section).
   
   Before starting, put on fresh gloves and mask and disinfect your entire workspace. Also disinfect your monotub (which you will use as a still air chamber) and any tools (like a scalpel). Turn off fans, close windows. 

   
   

   You want the air to be as still as possible.
   
   Flip the monotub upside down and place a clean rack inside. Place your two colonized agar jars and two sterile grain jars inside the tub. Seal the tub’s holes completely with duct tape so no outside air can enter. Now your tub is a still air box.
   
   Wait 20 minutes for air particles and contaminants to settle at the bottom. This creates a pocket of clean, still air inside. (See “Still Air Box” section below for more on how this works and why it helps prevent mold.)
   
   After 20 minutes, remove the tape from the working ports. Re-disinfect your gloves, then loosen, but do not fully remove, the lids of the first agar and first grain jar. Flame-sterilize your scalpel outside the box. 

   
   

    Remove the lid from the agar jar, cut out a few small chunks of mycelium/agar, then immediately open the first grain jar and drop the agar pieces in. Quickly re-close the grain jar. If any substrate spills or falls out, discard it – don’t put it back.
   
   Rotate the jars around on the rack so you can work easily, sterilize the scalpel again, and repeat the transfer for the remaining jars: bits of agar into each grain jar. Once done, shake each grain jar thoroughly to distribute the mycelium throughout the jars.
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   Working in a still air box (SAB) with gloves greatly reduces contamination. After transferring, shaking the grains (break and shake) is crucial: it creates more “inoculation points” and speeds up colonization.

   
6. 6.

   Setting Up and Using a Still Air Box

   A Still Air Box (SAB) is simply a clean, sealed container used to isolate your work from airborne contaminants. By completely closing off the box and waiting 20 minutes before opening the ports, you allow dust, bacteria, and mold spores in the air to settle out inside the box. With no airflow stirring them up, the air you work in remains clean and still. In practice, you wear gloves and reach into the two side holes (ports) to handle your jars and tools. 

   
   

    Benefits: Using a still air box makes it much easier to keep transfers sterile. Millions of microscopic contaminants float in any room, but in a sealed SAB they fall and settle. Once you’ve waited 20 minutes, you’re working inside a clean air environment with only the particles that settled at the bottom. Always disinfect your gloves and tools again before reaching in. Work calmly and avoid quick movements that could disturb settled particles. After finishing your transfers, disinfect everything again.
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   A still air box is one of the simplest yet most effective still air box tek tips. Always wear gloves and a mask (sometimes called still air box gloves when used in this context) when working inside. The cleaner the air, the healthier your mushrooms will be.

   
7. 7.

   Grain Colonization and the Break and Shake Method

   Store the inoculated grain jars in a dark place at 21–27 °C (70–80 °F). Within a week or two, white mycelium will spread throughout the rice. When a jar is about 30–40% colonized, perform the “break and shake”: shake the jar vigorously to break up the colonized clumps. This evenly distributes the mycelium and creates many new growing points, accelerating colonization.
   
   After shaking, return the jar to incubation. 

   
   

   Continue storing in optimal temperatures. Eventually each grain jar will turn completely white (fully colonized).
   
   At this point, inspect each jar closely. If you see anything green, black, or any odd color, or notice a sour smell instead of a fresh earthy smell, that jar is contaminated – discard it immediately (preferably outside) to protect the others. Once all jars are fully white and contamination-free, your spawn (colonized grains) is ready for bulk substrate.
   
8. 8.

   Preparing Coco Coir Substrate to Perfect Field Capacity

   Next, prepare your substrageThis guide uses coco coir as the substrate. First, place about 300 g of coco coir in a clean 5-liter pot or bucket. For the ideal moisture level, also calles perfect field capacity, use a 1:5 ratio of coir to water. For 300 g coir, boil 1.5 L of water and pour it over the coir to pasteurize it. Since coco coir is naturally resistant to mold, it doesn’t need full sterilization. Let it sit, covered, for at least 6 hours or until it cools.
   
   Once the coir is cool, wear fresh gloves and a mask and mix the coir thoroughly by hand. You can test it: grab a handful and squeeze. If only a few drops come out, field capacity is perfect.
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   Plain coco coir is perfectly fine for beginners; there is no need for vermiculite or gypsum.

   
9. 9.

   Preparing the Monotub and Liner

   Meanwhile, prepare the monotub liner which helps to prevent side pins. Cut 8 strips of duct tape and put the liner into the monotub. Fold the corners of the liner up and tape them together at the center, then tape the corners of the liner to the sides of the tub. This stabilizes the liner and keeps edges from peeling up later. Seal the larger still air box holes on the tub’s sides with duct tape.
   
10. 10.

    Spawn to Bulk Transfer Guide

    Before mixing in the grain, sniff the colonized rice: it should smell clean and earthy. If it smells sweet or foul, it’s contaminated and must be discarded.
    
    Empty the colonized rice spawn into the monotub. Break up any large clumps with your hands. Add half of the prepared coir on top of the rice and mix thoroughly from top to bottom, making sure no pockets remain.
    
    The goal is an even blend of rice and coir. Press the surface lightly to flatten it and particularly compress the edges. This helps prevent mushrooms from growing on the sides instead of the top. Then spread 3–4 handfuls of coir evenly on top as a casing layer. Lightly pat it down so no rice is visible; this casing helps retain humidity.
    
    Finally, put the lid on the monotub. Place it in the same 21–27 °C range. Lighting isn’t critical, just avoid direct sun. Keep in mind that there is no need to fan or mist with perfect field capacity.
    
11. 11.

    Monotub and Substrate Colonization

    Over the next 2–3 weeks, the grain spawn will colonize the coir. You’ll see white mycelium spreading outward and eventually covering the top. When you see the first small “pins” appearing, and most of the surface it colonized, it’s time to initiate fruiting conditions.
    
12. 12.

    Introducing Fruiting Conditions

    To trigger fruiting, you need fresh air exchange. During colonization, CO₂ built up inside the sealed tub. Mushrooms need oxygen for fruiting, so we’ll open up for airflow while keeping contaminants out. Remove the all plugs covering the smaller holes and replace them with micropore tape.
    
    The micropore tape acts like filtered venting: it allows gas exchange (fresh air in, CO₂ out) but still blocks most contaminants. You can also use poly-fil or filter patches on the remaining holes instead of micropore tape.
    
13. 13.

    When and How to Harvest Golden Teacher?

    Once the mushroom caps begin to open and the veils start to tear, harvest within about 12 hours. The veil is a thin white-grey skin that stretches between the cap and the stem; when it breaks, the mushroom is mature. Harvesting in time prevents a deluge of spores. Grasp each mushroom at the base and use a twist-and-pull motion, or cut at the base with a sterilized scalpel. Mushrooms bruise blue where handled; this is normal and harmless.
    
    You may pick all the mushrooms at once, or harvest the largest ones and leave smaller ones to mature for another day. If you do that, simply put the liner back, reclose the tub, and wait a few hours.
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    Tip: If small “side pins” appear along the edges of the substrate, use a scalpel to cut them out – they can be hard to twist off. Harvesting by a gentle pull tends to include roots, which may cause small damage to the substrate. Cutting preserves substrate health for future flushes.

    
14. 14.

    How to Take a Mushroom Spore Print?

    If you want to collect spores (to grow another batch), take one fully mature mushroom cap (after harvest) and make a spore print. Sterilize a piece of aluminum foil and a bowl.
    
    Cut off the stem and place the cap gills-down on the foil. Cover it with the bowl to keep air still, and wait 24 hours. Spores will fall onto the foil.
    
    After 24 hours, lift the cap and let the spores dry another 24 hours on the foil. Fold the foil up to store the print. Keep it in a dark, dry, cool place; spores can remain viable for years.
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    It’s wise to make multiple prints to increase chances of having a clean one.

    
15. 15.

    Drying Mushrooms Using a Dehydrator

    To preserve your harvest, dry the mushrooms until they snap easily (“cracker dry”). First, clean off any substrate bits from the stems. Avoid oven or air-fryer drying (too high risk of burning). If you have a dehydrator, spread the mushrooms on the trays without overlap.
    
    You can slice large specimens to speed drying. Set the dehydrator to the lowest heat possible and run for 8–12 hours, or until every piece cracks rather than bends.
    
16. 16.

    Drying Mushrooms Using Drying Packs

    Start by pre-drying your harvest with a fan for about 12 hours to remove the bulk of the moisture, then transfer the mushrooms to an airtight container layered with paper towels and drying packs. Store the container in a dark, cool spot for 24 hours before reactivating the packs in the oven or microwave to restore their absorption power. Repeat this cycle until the stems are "cracker dry" and snap cleanly without bending to ensure they are safe for long-term storage.
    
    For the complete, detailed instructions on how to dry mushrooms with drying packs, please see the full blog post linked at the very end of this page.
    
17. 17.

    Rehydrating Substrate for a Second Flush

    Directly after harvest, prepare your monotub for the second flush. Pour 1.5 L (1.6 qt) of cold tap water straight onto the substrate while it’s still inside the liner. Cold water helps prevent bacterial blooming during rehydration. If the substrate floats, that’s okay. It will still absorb the water. Close the lid and let the substrate soak for about 12 hours.
    
    After soaking, pour off any excess water (hold the substrate firmly so it doesn’t fall out). Put the liner back in, close the monotub, and return it to the same location and conditions you used for fruiting. New pins should form and the second flush will develop. Repeat this rehydration process after each harvest; most monotubs give three to four flushes (sometimes up to seven) if you care for them properly.
    
18. 18.

    Inoculating Agar from a Spore Print

    To create new cultures from a spore print, you can inoculate fresh agar directly with spores. Prepare fresh agar plates as described in the Agar section and flame-sterilize your scalpel. Loosen the lid of a jar with agar, then carefully unfold a clean spore print.
    
    Using a clean scalpel or a sterile knife tip, scrape about a knife-tip amount of dry spores (that’s more than enough) from the print and place them gently onto the agar surface. Close the jar and seal it. Incubate the inoculated agar in the same dark 21–27 °C (70–80 °F) range. The spores will germinate and form mycelium.
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    It’s wise to inoculate several agar jars at once to hedge against contamination.

    
19. 19.

    Cloning Mushrooms on Agar

    If you had any exceptionally large or healthy mushrooms, you can clone them to preserve their genetics. Work sterile as before. Cut a mushroom in half and take a small piece of inner tissue from the cap. Flame-sterilize a scalpel, then place the tissue piece onto a fresh agar plate.
    
    The mycelium will grow out from it just as with spores. This way, you have a pure culture of that particular mushroom’s.
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    Always use inner tissue (not the outer flesh) for cloning; the interior is most likely sterile. Label the agar so you know which mushroom it came from.