The Basics Of Mushroom Growing.
Mycology (the study of Fungi) is rapidly gaining popularity as society comes to the realization that fungi can provide several physical, cognitive, economic, environmental, and psychological benefits. Fungi are some of the oldest organisms on the planet, and interestingly shared a common ancestor with humans until about 1.5 billion years ago, when they split from the “animalia” branch of the tree of life. This split occurred when organisms in the animal branch began to encapsulate nutrients in a cellular sack (a stomach) for digestion, whereas Fungi continued to digest at an individual cellular level.
Fungi propagate their genetic code through the dispersion of spores, and survive by consuming non-living nutrients from their environment (mostly in the form of detritus and decaying material). Therefore, they play a crucial role in the health of any ecosystem as they are the primary decomposers of both plant debris like cellulose/lignin and dead/decomposing animal tissue. Furthermore, they also have extraordinary capacity to recycle/decompose toxic material, from petroleum oils, to nuclear waste.
The benefits which Fungi provide are not limited to the ecosystem level, and they can also have significant benefit to both the physical and psychological health of an individual. Several edible/gourmet mushroom species (Lions Mane and Shiitake in particular) promote increased cognitive, cardiovascular, and mental health, while Psychoactive varieties (Psilocybe Cubensis in particular) have shown remarkable results in the treatment of many psychological conditions.
These benefits have catalyzed many people in Canada to begin growing their own mushrooms for use as nutrition OR medicine, and while the greatest information repository known to man (the internet) is filled with forum posts/homemade tutorials, most of which give a glossary overview and closer resemble an “easy bake cookies” recipe, rather than an in-depth manual/tutorial describing the intricacies of the mushroom life cycle.
There are several excellent resources that have been published in print (Like The Mushroom Cultivator by Paul Stamets) however we at Spores Lab want to make information on how to safely and efficiently grow your own mushrooms free for all individuals to benefit from!
Before we get into the specifics of cultivation, let’s go over the basics of the mushroom life cycle under natural conditions.
Mushroom Mycelium consists of a mass of branching root-like strands, each strand a single cell thick, called Hyphae. Mycelium can be described as the vegetative portion of a fungus (where all nutrients and energy are put towards growth instead of gene propagation). A Mushroom culture will continue to grow in the "mycelial state" as long as nutrients are available, and as long as the environmental conditions are congruent with this “stage” of the mushroom life cycle. This part of the life cycle (where the mycelium is growing but no mushrooms are present) is often called “spawning” or “colonization”.
The next step in the mushroom life cycle happens once mycelium has fully “colonized” the medium it is growing in. At this point (under natural conditions) changes in environmental conditions (like temperature and humidity) will trigger the mycelium to switch from a “spawning” (mycelium) state to a “fruiting” (mushroom) state. In this fruiting state mushrooms will grow out of the mycelial mat, and mushrooms will continue to sprout until all available nutrients and moisture in the environment are depleted, or environmental conditions are changed back to conditions congruent with mycelium growth.
Explained above is the mushroom life cycle under natural conditions, however when cultivating in an artificial environment certain steps (like working from an isolated culture, or adding extra nutrients via a fruiting medium before switching to fruiting conditions) can be taken to increase potency and yield. Most people will begin the cultivation process, with a mushroom spore syringe or Liquid Culture syringe, however a syringe is not the only way, and not necessarily the most efficient way to grow mushrooms (especially at scale).
Advanced mycologists can clone mushroom tissue by placing it in an *agar medium*. This process (called “isolation”) creates a culture that has a narrow genetic profile, and often results in faster ‘colonization’ time, higher yield, larger fruiting bodies (mushrooms), and increased potency. Further isolation from the initial mushroom tissue sample can be done using agar, by selecting especially strong mycelial strands and propagating these onto a new agar petri dish.
Another way in which yield can be increased when cultivating indoors is through the addition of a “fruiting medium” when the mycelium has completely colonized its initial medium. A fruiting medium provides more capacity for water retention, provides some nutrients, and creates a larger surface area on which mushrooms can form.
*Agar is a high-nutrient gelatinous medium, the caveat to working with isolations/agar is that a “flow hood” is highly recommended. (a flow hood consists of a HEPA filter enclosed in a box with a fan situated opposite the filter. This allows filtered are to be continually blown over your workspace)*
Since this guide is aimed at the “hobby” cultivator, we will cover the process of cultivation using a Spore Syringe. That means this guide can also be applied if you are using a Liquid Culture Syringe. If you are interested in learning more about agar cultures, or commercial scale growing, please contact us!
Regardless of whether you will start with an Isolation in an agar medium, a Liquid culture Syringe, or a Spore print/syringe, you will need to procure some supplies and equipment. We recommend budding mycologists begin with a “Still Air Box” (instead of a Flow Hood which is quite expensive), a stovetop pressure cooker, and use jars with inoculation port lids.
*An inoculation port lid has a rubber self-healing injection port for error-proof inoculation.
*A pressure cooker is used to sterilize the mediums that the mushrooms grow in
*A Still Air Box (SAB) is a container that provides an area with no airflow. One can be built for ~$50.
It is imperative that we now stress the importance of STERILITY. When you grow mushrooms, you aim to create a perfect environment for fungal growth. Unfortunately this environment is also ideal for bacterial spread, or the spread of other unwanted fungi.
Every cubic meter of air (in an unfiltered environment) contains millions of fungal and bacterial spores, and each of these spores can potentially compete with your desired culture. You must take extreme care to clean/disinfect all surfaces, tools, & body parts that may come into contact or come near your mushroom culture. This is also why spawn medium and fruiting medium must be sterilized/pasteurized in a pressure cooker, and why a SAB/Flow hood is so important.
STEP 1 - Preparing Spawn Medium.
Once you have sourced a sterilizer and built a still air box (or flow hood), the first step is to prepare the spawn medium. There are several mediums that can be used, however if you desire the maximum yield possible, Rye Grain Berries are the best option (Rye grain can be soaked to an Equilibrium Moisture Content (EMC) of ~ 47%)(higher than any other grain).
Organic, NON-Fungicide Rye Grain Berries
Begin by placing the grain in a 5 gallon bucket, then fill the bucket with cold water and pour out the water (just the water) several times until the water is pouring out noticeably more clear than at the start.
Then fill the bucket 6-8” above the grain level and leave the grain to soak for 24 hours. This soak serves to hydrate the grain, and also causes the endospores of any contaminants which may be present in the grain to germinate, so they can be killed during sterilization (an un-germinated endospore CAN survive sterilization).
When you return (24hrs later) the water level will have dropped, meaning that the grain has absorbed this moisture. Pour out the remaining water and fill the bucket 6” above the grain level, this time with HOT water (NOT BOILING WATER, JUST TAP WATER AT MAXIMUM HEAT).
Let the grain sit in this hot water for 20 minutes. This heat differential allows the grain to fully “plump” and absorb the maximum amount of moisture possible. After 20 minutes pour out the hot water and strain the grain using a colander until the colander stops dripping. Next spread the grain out evenly in a tray/tub/tote and place it in a high-airflow area for about 1 hour to dry the exterior of the grain berries (the container you will fruit in later on in the growing process usually works well).
Grain drying in the Spores Lab Facility
Ideally you want the grain berry to be as saturated as possible, but little moisture on the exterior surface of the grain berry (the industry term for this level of saturation is “field capacity”). A rough “rule of thumb” you can use to estimate the correct dryness is picking up a small handful of grain then turning your hand upside down. A few grains should stick to your hand.
Now place the grain in your colonization container (we recommend using MYCO-PRO Spawn Jars), seal the container, and place it in your sterilizer. Ensure that the lid of the sterilizer is properly and evenly seated.
Cook times will vary based on whether you use an electric heated pressure cooker or a stovetop pressure cooker.
If using a stovetop cooker, pressure cook at 15PSI for 2.5 hours.
If using an electric heated pressure cooker, pressure cook at 15PSI for 4 hours.
*If your sterilizer does not have the capacity to pressurize to 15PSI, add 1 hour to the cook time*
Also be cognizant of how much grain you put in the jar/bag, keeping in mind that putting more medium will take longer for the container to colonize. We recommend filling a spawn jar ¾ full, and filling a type 3T bag about ½ full of hydrated grain.
After the cook, let the sterilizer cool for ~1 hour and then clean the surface of the sterilizer BEFORE opening it. When you open the sterilizer there is a brief pressure differential that sucks some air into the sterilizer as the pressurized air inside the sterilizer escapes, and you want the area/surface as clean as possible when this happens.
*If you are using a regular mason jar we recommend also using an inoculation port lid, and if you are using a bag we recommend a Type 3T 0.2 micron filter autoclavable bag. If you are using a bag we also recommend cutting a small slit in the corner of the bag prior to sterilization, so the bag does not rupture during sterilization. Re-seal the bag (using an impulse sealer or a “mushroom bag clamp”) immediately after opening the sterilizer.
STEP 2 - Inoculation.
After you have removed the jars/bags from the sterilizer, you are now ready to inoculate! Inoculation should be done within 24hr of sterilization. This is because of the finite amount of moisture in the grain, moisture which has to last the entire life cycle. You will not only lose out on potential yield if you wait too long to inoculate, but you will also be giving the mycelium a more difficult environment to grow in.
Inoculation should ideally be done in front of a flow hood, or in a SAB, however if you are using an inoculation port lid then a SAB/Flow hood is not totally necessary, but still recommended.
Begin by putting on your PPE and cleaning. Don't be afraid to “overkill” for this step, as it’s this point where the risk of contamination is greatest. Wipe down the surface of the spore/liquid culture syringe, the surface of the colonization container, your arms, and all surfaces in the area with disinfectant. Gather your supplies and place them in the still air box, or intelligently position them in front of the flow hood (with regard to the direction of airflow coming from the flow hood). If using a SAB place all supplies in the box, then put the lid on the box, put your hands in the gloves and liberally disinfect the interior of the box with an aerosol disinfectant spray.
A Screen Grab from our video tutorials - tutorials found here
Unwrap the sterile 18ga needle (which is included in our spore/liquid culture syringe products), remove the plastic Luer Lock tip from the syringe, and attach the needle to the syringe by inserting and twisting the needle.
Sterilize the needle (with either heat or disinfectant spray) then inject the needle into the inoculation port and depress the plunger of the syringe. (if you are using a jar with an inoculation port lid). If you do not have an inoculation port lid we recommend drilling a small hole (1/4") in the lid of the jar (if you are using a bag then the needle can be used to poke a hole in the bag). Immediately cover this hole with Micro-pore tape after inoculation.
We recommend inoculating with at least 5mL of Solution per 1L of container space. You can use more solution than this, and it will result in a faster colonization time (each of our syringes contains 10mL of spore or liquid culture solution), but we don't recommend using less than this amount.
STEP 2.5 - Colonization.
After you inoculate, shake the bag/jar to evenly disperse the liquid culture/spore solution, and then leave the bag/jar in an environment which has the right conditions for colonization (described below).
Colonize in an area that is mostly dark (the darker the better), has about 50% ambient humidity, and has steady temperature between 75-77F (23.8-25C) I's crucial that the temperature remains below 80F (26.5C) during the colonization stage.
Colonization from a spore syringe will take anywhere from 2-6 weeks depending on how much grain is in your container, how much spore solution you inoculate with, and how optimized you are able to make the environmental conditions.
Colonization from a Liquid Culture syringe will take anywhere from 2-4 weeks. LC syringes will consistently colonize faster than spore syringes because an LC syringe contains an already alive and growing mycelial culture.
The container is “fully” colonized when you are barely able to see grain, and the majority of the jar/bag is a solid block of white mycelium.
An uncolonized grain jar
A partially colonized grain jar
A fully colonized grain jar
If at any point during the colonization period you notice a pungent odour coming from the container, or notice any coloration that is NOT white mycelial growth, quarantine that container from the rest of your operation immediately and dispose of it. It has likely become contaminated and if you do not remove it from the area it will contaminate the containers around it.
Various forms of contamination
STEP 3 - Making a Fruiting Substrate.
Once your colonization medium is fully colonized you are now ready to add a nutrient rich, high water-retention, pH balancing fruiting medium to form what is called a “Fruiting Substrate”. Like colonization mediums, there are many options for a fruiting medium, however we recommend using our tried and tested MYCO-PRO™ Fruiting medium.
We have, after years of development, testing, and refining, created an ideal and easy to use fruiting medium, which is a mix of Vermiculite, Coconut Coir, Spaghum Peat Moss, Worm Castings, and Calcium Carbonate (CaCO3). Laboratory testing done on this medium after 4 flushes of mushrooms had already been harvested showed that there were still ample nutrients & minerals left in the substrate, and pH was still well within the accepted range for fungal growth.
If you want to purchase the inputs and mix them yourself (instead of purchasing the medium from us), here is the recipe -
Begin by mixing the Vermiculite and Coconut coir at a 50/50 ratio by volume (litres).
Next add 100 grams of powdered CaCO3, 500 grams of Peat Moss, and 300 grams of worm castings for every 40 Litres of dry mix.
Then add 1.25 litres of water for every 4L of dry mix, and mix well.
Keep mixing and adding small amounts of water until the medium drips a steady stream when lightly squeezed. The reason we recommend starting with 1.25L of water for every 4L of dry mix, then adding water as needed is due to variance in hydration level of the ingredients from different suppliers. Alternatively, if you use MYCO-PRO™ Fruiting Medium, simply add 1.25L of water for every 4L of dry mix for pretty close to perfect moisture content.
When the proper moisture content has been achieved (when the mixture drips when lightly squeezed) you can EITHER -
Sterilize the medium - by placing in a Type 14A 0.5 micron filter autoclavable bag and cook the medium at 15PSI for 90 minutes.
Pasteurize the medium - by placing in a Type 14A 0.5 micron filter autoclavable bag and cooking in a conventional oven at 180 Fahrenheit for 6 hours.
*If using a pressure cooker, don’t forget to cut a small slit in the corner of the bag so it does not rupture during sterilization*
Once you remove the sterilized fruiting medium from the cooker and allowed the medium to cool, you are now ready to mix it with the colonized grain spawn to create a “Fruiting Substrate”.
This job will be very difficult to perform in a SAB, so we recommend it’s performed in a clean area, and preferably in front of a flow hood. Cleanliness is not AS crucial for this job (compared to inoculation) as by this point the mushroom culture is established and can fight off potential contaminants, however sterility is still very important and overkill doesn't hurt. Wipe down the surface of the spawn bag/jar, the surfaces of the tray/tub/tote that you will fruit in, your tools, your hands and arms, and the surface of the bag that the fruiting medium was sterilized in. Position your supplies so that you don’t have to reach over the fruiting substrate container to grab them, and be cognizant of airflow if you are using a flow hood.
Begin by putting on your PPE (gloves, mask, hairnet) and placing the fruiting container (the plastic tub/tote/tray that you will fruit in) inside a black plastic garbage bag. Reach into the tub/tray/tote and tamp the garbage bag to the corners of the tray, being careful to touch the bag minimally. Now cut along the top of the fruiting medium bag and pour this into the tub/tray/tote. Repeat this process for the colonized grain bag or jar.
We recommend the mixture be roughly 25% colonized spawn and 75% fruiting medium.
A Screen Grab from our video tutorials - tutorials found here
Mix the two mediums well. You want everything to be as well dispersed as possible to allow optimal colonization of the fruiting substrate in the shortest amount of time. After the substrate is mixed well, tamp the surface lightly with a BBQ flipper so that it is as flat as possible. This is to avoid water pooling during the incubation of the fruiting substrate (note - colonization/spawning refers to one medium being colonized, whereas incubation refers to a substrate, or a mix of mediums being colonized).
Now put the lid on the tray/tub/tote, cut the garbage bag about 2” below the lid all the way around the tray, and remove the excess bag. Mark the date, strain, and any other relevant information on the outside of the tub with a sharpie.
STEP 3.5 - INCUBATION.
After you mix your fruiting substrate in the fruiting container, leave it in an environment which has the right conditions for incubation for approximately 7-10 days.
Incubation should take place in an area that is mostly dark (darker the better), has about 50% ambient humidity, and has steady temperature between 75-77F. It is crucial that the temperature remains below 80F during incubation.
You should also check the incubating tray/tub/tote periodically to make sure there is no water pooling on the surface of the fruiting substrate. If water is pooling remove the lid, wipe any water collecting on the lid, put the lid back on, and lower the ambient humidity slightly.
If at any point during the incubation period you notice a pungent odour coming from the tub/tray/tote, or notice any discoloration that is NOT white mycelial growth, quarantine that tray/tub/tote from the rest of your operation immediately and dispose of it. It has likely become contaminated and if you do not remove it from the area it will contaminate the trays/tubs/totes around it.
The fruiting substrate is fully incubated when the surface is completely white with mycelium.
A fully incubated fruiting tray in the Spores Lab Facility
A freshly mixed fruiting tray in the Spores Lab Facility
STEP 4 - Triggering Fruiting.
Once the fruiting substrate is fully incubated you are now ready to trigger fruiting by changing the environmental conditions.
The three major changes you will make are the humidity level, the light schedule, and the amount of airflow.
These changes mimic the natural environmental changes that occur when a mycelial culture reaches the “edge” of the medium it is colonizing. A good analogy is a compost pile. When mycelium begins life deep inside the compost pile it is in a dark and low-airflow environment. As it grows towards the edge of the pile it is exposed to light and higher oxygen levels, which trigger pinning. Adding humidity also serves to trigger pinning (which is why in nature mushrooms often sprout after a heavy rainfall) and additionally can extend the fruiting period by providing some moisture for the culture to absorb and turn into fruiting bodies (which are up to 90% water).
At this point you should switch from a constantly dark environment to a 12/12 light cycle (12 hours light 12 hours dark). Any light spectrum will work, however slightly “cooler” lighting between 6000 and 7000 Kelvin is ideal.
Ideal lighting for fungal growth is in the 6-7k kelvin range
At this point you will switch the lid of the fruiting tray/tub/tote for a “fruiting dome” to allow more airflow to the mushroom culture. Usually using the same tray/tub/tote as you built the fruiting substrate in, flipped upside down works well. Cut a 2” hole in each corner of the dome and stuff this hole with Hi-loft Polyfil. This serves as a barrier for particulate matter/contaminants but allows airflow. We also use plastic clips to hold the dome to the tray.
Left - Incubation Lid Right - Fruiting Dome
At this point the humidity in your tray/tub/tote environment should also be raised. Accomplish this by misting the surface of the fruiting substrate daily, or whenever there is NO humidity build up on the sides of the fruiting dome. Set your sprayer to create as fine of a mist as possible. You do not want large droplets or pools of water on the surface of the fruiting substrate.
How much you will need to mist also depends on the ambient humidity and the amount of ambient airflow in your growing space. You can skip a day of misting if there is excessive humidity buildup on the sides of the fruiting dome or if there is water pooling on the surface of the mycelial mat. Ideally you want to put as much (clean) airflow as possible through the controlled dome environment, but you also want the highest humidity possible in the controlled dome environment.
After approximately 7-10 days in these conditions small Primordia or “pins” will form. These will quickly grow into mature fruiting bodies within 3-5 days. You should cease misting the surface of the fruiting substrate once pins begin to show, but still try and keep the humidity as high as possible in the tray/tub/tote. You can do this by misting the sides of the dome (instead of directly misting the surface of the substrate).
Primordia (pins) beginning to form
STEP 5 - Harvesting/Taking Spore Prints.
You are now at the most enjoyable and rewarding part of the cultivation process! Your patience and hard work over the past weeks/months is finally paying off, and beautiful shrooms are fruiting out of your fruiting substrate. You should aim to harvest your mushrooms right after the “veil” separating the cap and stem breaks, and the cap begins to open.
Cut the mushrooms cleanly off at the base of the stalk using sharp scissors. Scissors with slightly curved blades work excellently. Also try not to touch the surface of the mycelium when harvesting, wear gloves when harvesting, and try to handle the mushrooms the least amount possible. You should be harvesting a few mushrooms almost daily, as some caps will open before others. When all the mushrooms in a “flush” have been picked you can mist the surface of the fruiting substrate again to keep the humidity as high as possible for the next flush!
Successive flushes will continue to happen until the mushroom culture has used all of the available nutrients and humidity in the fruiting substrate. Typically a home/hobby cultivator should be happy with 1-2 flushes before contamination starts to appear, at which point the culture needs to be disposed of. If you are cultivating in a cleanroom environment you can get up to 5/6 flushes.
If you will be taking a spore print you will need to let the veil separating the cap and stem fully break and the cap open about ½ way. Then cut the cap off close to where the stem meets the cap, and place the cap on a piece of tin foil. Leave the cap on the tin foil for about 12 hours (this should also be left IN a SAB or in front of a flow hood). A good rule of thumb for knowing when to cut the cap off is when the cap is at its most triangular shape (the cap starts as a concave bulb shape and opens to become convex if you let it go long enough). The triangular cap shape occurs at about the halfway point in this process and is ideal for catching the entirety of the spore print.
Spore Prints taken in the Spores Lab Facility
When you return remove the cap from the tin foil and the spore print will have been deposited. You can now scrape the spores into a sterile aqueous solution (sterilized water) and draw the solution into a syringe to create a spore syringe! Or you can keep the spore print for long term storage (prints remain viable for up to 10 years, possibly longer).
STEP 6 - Drying Mushrooms
The drying process for mushrooms is extremely easy, just place the mushroom fruiting bodies in a low humidity, moderate temperature, high airflow area for 2-4 days. Near a dehumidifier is ideal, but if you do not have a dehumidifier near a fan will also work, albeit slower. Using a food dehydrator will also work, if you have one. If using a dehydrator simply place the mushrooms in the dehydrator for 6-8 hours.
They are dry when the stems crack when the mushroom is bent.