How to Use Our Mycelia on Grains?
🌱 Introduction: How do mushrooms grow?
Unlike plants that feed through photosynthesis, fungi decompose organic matter. For the mycelium to fruit (produce mushrooms), it needs a substrate, that is, a material that serves as its food. The quality and preparation of this substrate are crucial to obtaining an abundant and good quality harvest.
🍄 What is a substrate?
A substrate is a nutrient support on which the mycelium develops; it is its food. Choosing the right substrate is essential because it directly influences the colonization speed, the quality of the mushrooms, and their yield. Here are some examples of commonly used substrates:
- Straw: Rich in fiber, ideal for oyster mushrooms. It must be pasteurized before use to eliminate contaminants.
- Wood sawdust: Perfect for shiitake and other wood-loving mushrooms. Prefer hardwoods (oak, beech) for better results.
- Straw or wood pellets: Practical and easy to store, they are often pre-pasteurized, which simplifies preparation.
- Cardboard: Inexpensive and easy to find, it is used for cultivating hardy varieties such as oyster mushrooms.
- Coffee grounds: Rich in nutrients, it is particularly suitable for urban farming and small-scale cultivation.
The choice of substrate depends on several factors:
- The mushroom variety: some prefer substrates rich in cellulose (oyster mushrooms), others in lignin (shiitakes).
- Growing conditions: indoors, sterilized or pasteurized substrates are often preferred to avoid contamination. Outdoors, less processed substrates can be used.
By understanding the needs of the mycelium and choosing the right substrate, you maximize your chances of successfully growing your culture.
📑 Table of Contents
1. How to use our myceliums on grain spawn? 🧪
- Choose your substrate: Select a substrate suitable for the mushroom variety (straw for oyster mushrooms, sawdust for shiitakes, etc.). Our optimal substrate works well for most varieties on our site.
- Prepare the substrate: To limit contamination, pasteurize (heat) or sterilize (pressure cooker) your substrate according to the recommended method.
- Inoculate the substrate: Once the substrate has cooled, incorporate the mycelium onto grain spawn by distributing them evenly.
- Incubez : Place the mixture in a clean and controlled environment (20-25°C for oyster mushrooms), maintaining high humidity.
- Trigger fruiting: Once the substrate is fully colonized (whitish and compact), adjust light, humidity, and temperature to encourage the appearance of the first mushrooms.
Tip: Regularly check the state of colonization. If you observe green or black spots, these are likely contaminations (mold). To prevent contaminations from spreading from one bag to another, separate those that are contaminated.
🌾 Examples of Easy Crops:
1. Oyster Mushroom on Straw (Outdoor or Indoor Cultivation)
Oyster mushrooms are known for their rapid growth and their ability to colonize a wide variety of substrates, including straw.
- Substrate: Chopped straw or straw pellets.
- Preparation: Soak the straw in hot water (75°C) for 1 hour to eliminate contaminants.
- Inoculation : Once cooled, mix 5 to 10% of mycelium on grain spawn with the damp straw.
- Incubation: Place everything in perforated bags or buckets with holes, at 20-25°C, for 2 to 3 weeks.
- Fruiting: Expose the substrate to indirect light with 80-90% humidity.
NoteThere is an alternative technique to heat pasteurization which is pasteurization with lime. To do this, use slaked lime (white limestone lime). Dilute one cup for about 50 liters of water.
Soak the straw overnight (12h) in this lime water. This will allow the straw to moisten and raise its pH (=make it more alkaline), which will create an environment unfavorable to the development of bacteria or molds and rather favorable to the development of oyster mushroom mycelium.
You can also use our organic straw pellets, which are already pre-pasteurized and well suited for oyster mushroom cultivation.
2. Shiitake on Wood Sawdust (Indoor Cultivation)
Shiitakes are wood-decaying mushrooms that ideally grow on a sawdust substrate.
- Substrate: Hardwood sawdust (oak, beech).
- Preparation: Mix the sawdust with boiling water to reach about 60% humidity.
- Inoculation : Once cooled, add 10% of mycelium on grain spawn.
- Incubation: Maintain at 20°C for 10 to 12 weeks, in filter bags.
- Fruiting: After colonization, remove the bag and place it in a humid environment (15-18°C).
Tip: To encourage shiitake fruiting, create a thermal shock by placing the colonized block in a cool place (4°C) for 24 hours.
2. The Importance of Working Neatly
Cleanliness is a key success factor in mushroom cultivation. Whether you work in a laboratory or an outdoor environment, maintaining clean working conditions will minimize the risk of contamination.
Classic question: "Yes, but in nature, mushrooms grow on their own, so why should I pasteurize or sterilize my substrates?"
In nature, mushrooms grow without human intervention, but the conditions are unpredictable and hostile: insects, molds, bacteria, drought, frost, UV... Only the most resistant survive, hence the production of millions of spores in the hope of fruiting.
In controlled cultivation, the goal is to maximize the chances of success. Pasteurization reduces contaminants, allowing the mycelium to quickly colonize the substrate. Working cleanly prevents adding parasites and is essential for sensitive varieties.
In summary, cleanliness and pasteurization ensure safer and more productive cultures compared to natural conditions.
A. Working Conditions for Resistant Varieties
Some varieties, such as oyster mushrooms, are more tolerant of non-sterile working conditions. If you are working with a substrate low in sugar and nitrogen, such as straw, the risk of contamination is low. In this case, pasteurizing the substrate is sufficient and you can inoculate it in open air. However, even under these conditions, cleaning surfaces and tools is recommended.
Tip: If you are working outdoors, inoculating after rain can reduce the risk of contamination. Rain cleans the air and decreases the number of airborne particles, thus creating a purer environment for inoculation.
B. Working Conditions for Sensitive Varieties
For more demanding varieties, such as shiitakes or lion's manes, which require an enriched substrate, more thorough pasteurization or sterilization is necessary. Working in sterile conditions is essential to avoid contaminations that could compromise the cultivation.
Home tip : When sterilizing an enriched substrate in a pressure cooker, open the cooled bag in an environment as clean as possible. Place the mycelium on the surface of the substrate without mixing it immediately.
This technique gives the mycelium a competitive advantage over potential contaminants, which come into direct contact with it. The incubation is a bit longer than without the mixture, but the risk of contamination is greatly reduced.
C. Cleaning the bag
When using mycelium in the laboratory, it is essential to maintain strict sterile conditions to avoid any contamination.
Steps to follow :
- Clean the outside of the mycelium bag with a 10% bleach solution or 70% alcohol.
- Break and crumble the mycelium by gently massaging the bag, being careful not to tear it.
- Sterilize the scalpel blade by heating it in the flame, then open the bag.
- Gradually pour the contents of the bag into the sterile substrate, avoiding any contact between the edges of the bag and the inside of the container holding the substrate.
Recommendation It is preferable to use the entire contents of the bag at once to minimize the risk of contamination. If this is not possible, close the bag as cleanly as possible and reuse it quickly. Nevertheless, our experience shows that this increases the risk of contamination.
3. Optimal Storage of Mycelia
Our myceliums on grain spawn are living products, sensitive to time and storage conditions. Upon receipt, it is imperative to use them as quickly as possible to preserve their vigor and minimize the risk of contamination.
Why is speed essential?
Mycelia are composed of active fungal cells that continue to grow and evolve even after the complete colonization of the grain spawn. The shorter the delay between receipt and use, the more vigorous the mycelium is and the more effectively it can colonize the substrate.
Anticipation of production lead times When ordering, it is important to take into account a production lead time that can vary between 1 and 4 weeks. To ensure delivery at the right time, we recommend placing your order in advance and, if necessary, specifying the desired delivery date in the comments during payment. This allows you to have fresh mycelium ready to use upon receipt.
A. Storage Temperature
Ideally, mycelia should be stored in the refrigerator at a temperature between 1 and 5°C. This temperature range slows the growth of the mycelium without damaging it, thereby extending its lifespan up to 4 weeks.
For mycelia of exothermic varieties, such as oyster mushrooms, it is particularly important to space the bags in the refrigerator to allow sufficient air circulation and an even distribution of cold.
B. Precautions for Long-Term Storage
For long-term storage, you can cover the filter with adhesive tape. This precaution reduces air entry and thus limits the introduction of potential contaminants through the filter. However, even with these precautions, we recommend using them within 3 to 4 weeks, as the viability of the mycelium decreases over time.
Factors influencing the lifespan of mycelia :
- Strain: Slow-growing strains have a longer lifespan.
- Storage temperature: A stable and low temperature is essential to extend shelf life.
- Storage conditions: Good air circulation and spacing of the bags contribute to optimal preservation.
Signs of mycelium aging :
- Compaction of the mycelium, making it less crumbly.
- Appearance of crusts or lumps on the surface of the grain.
- Production of colored liquid, sometimes foul-smelling, sign of degradation.
- Autolysis of the mycelium, leading to the degradation of the product. At this stage, it is no longer usable.
How to identify usable mycelium?
Even if the mycelium shows signs of aging such as compaction or crust formation, it can still be used. However, it is best to use it before the appearance of colored liquids, which is a sign that autolysis has begun.
Degeneration and Generations in Mycology
Tracking mycelium generations is essential to ensure the vigor, productivity, and stability of fungal cultures. Each stage – from the Petri dish to the liquid culture, then to the mother grain, the grain spawn, and finally to the substrates – corresponds to a generation (G0 to G4).
We speak of degeneration when a mycelium loses vitality, develops morphological abnormalities, or becomes less efficient in fruiting. Contrary to a common belief, this degeneration is not only related to the number of successive duplications. It is often favored by a lack of nutritional diversity, a poor substrate, or even a lack of physiological activity of the mycelium when it remains inactive for too long.
Maintaining a good level of stimulation (exposure to a favorable environment, renewal of various substrates, good growth rate) allows the mycelium to retain its vigor longer, even after several generations. Good monitoring of genetic traceability (e.g., generation G2, G3…) is therefore essential to avoid strain exhaustion and ensure quality harvests.
4. Amount of Mycelium to Use Relative to the Substrate
The amount of mycelium to use depends on the variety being cultivated and the type of substrate. Here are some recommendations based on our experiences:
- Oyster mushroom on straw: Use about 10% mycelium relative to the weight of the wet substrate.
- Shiitake on sawdust: A similar or slightly higher proportion is recommended.
- Stropharia in the garden on straw: Under non-sterile outdoor conditions, increase the proportion to about 20% mycelium on grain spawn.
Under sterile laboratory conditions, it is possible to reduce the amount of mycelium to 2-3%, or even 1%, of the substrate weight. However, in an outdoor or less controlled environment, a higher amount of mycelium is necessary to minimize the risk of contamination.
Why is this important?
Using an insufficient amount of mycelium increases the risk of contamination, as the mycelium will take longer to colonize the substrate, thus allowing other organisms to settle.
The mycelium on grain spawn can also be seen as a way to enrich its carbon substrate, and thus a larger amount of mycelium will potentially increase the productivity of the bales as well.
6. Mycelium Viability Test
If you have any doubt about the viability of your mycelium, it is possible to test it in different ways:
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Room Temperature Incubation : Keep the mycelium bag at room temperature (around 20°C) for 5 to 10 days. The mycelium should continue to grow and cover the grain spawn.
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Petri Dish Test : You can also take a small amount of mycelium and spread it on a pre-poured Petri dish. Observe the development of the mycelium over several days.
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Wet Cardboard Test : Pasteurize a piece of brown cardboard for 30 seconds in boiling water, then drain it. Place a small sample of mycelium on the cooled piece of cardboard. The mycelium should begin to colonize the cardboard within 5 to 10 days if it is viable.
Note: the appearance of the mycelium can vary from one variety of mycelium to another. For example, it is normal for lion's mane mycelium not to be as white and dense as that of the oyster mushroom. The smell and color can also vary depending on the varieties, and this is normal.
If it seems to you that the mycelium is not sufficiently visible upon receiving your package, it is probably because it was shaken during transport and the grain spawn have separated, which is not a problem in itself. The mycelium is indeed present inside the grain spawn and can be used as is. You can also choose to incubate it for a few days at 20° to see the mycelium merge the grain spawn again, indicating its vigor.
If you have any issues with one of our myceliums, do not hesitate to contact us.
7. Our quality guarantee
Our myceliums, or "mushroom whites," are seeds cultivated on grain spawn intended for substrate inoculation. Here is some additional information about our practices and products.
Local production and guaranteed quality
All our myceliums are produced in our laboratories in Gembloux, Belgium. We select our strains based on their vigor, natural disease resistance, taste quality, and productivity. We are inspected annually by Certisys for the organic certification of our myceliums, substrates, and mushrooms.
Maintenance of potential and vigor
We guarantee the purity and vigor of our strains through regular cultivation in non-sterile environments, followed by reproduction in a sterile laboratory environment. This method allows us to maintain robust and high-performing strains, ready to successfully inoculate your substrates.
Made to order
We produce our mycelia on order, with a production lead time of 2 to 3 weeks. This allows us to send you mycelia at the peak of their vigor, directly after incubation, without storing them in the refrigerator. These conditions ensure better resistance to transport conditions.