Mycelium production is the process of cultivating fungal root networks on agricultural waste substrates – such as corn stalks, sawdust, or straw – and guiding their growth into a dense, mouldable composite material. The process takes roughly 5–14 days from inoculation to finished product, requires no synthetic inputs, and produces a biodegradable material that can be composted at end of life. Here’s how it works, step by step.
The mycelium production process in 6 key steps
Step 1: Substrate selection
The substrate is the organic material that mycelium feeds on and ultimately binds together. Common substrates include:
- Agricultural byproducts – corn stalks, hemp hurds, straw, cottonseed hulls
- Wood-based waste – sawdust, wood chips
- Recycled paper – cardboard, newsprint
Substrate choice directly influences the density, flexibility and mechanical strength of the final material. Manufacturers often blend substrates to fine-tune properties for specific applications – packaging, insulation, or structural panels each call for different formulations. A comprehensive framework published in the Science of the Total Environment (2020) found that lignocellulosic byproducts – plant-based agricultural waste – consistently produce strong, reliable mycelial composites.
Step 2: Substrate preparation and sterilisation
Before inoculation, the substrate must be cleaned of competing microorganisms that would fight the mycelium for resources. This is typically done through:
- Pasteurisation – heating to around 80°C for several hours
- Sterilisation – higher-heat autoclaving for fully sterile environments
The substrate is then cooled and adjusted for moisture content, usually to around 50–60 per cent water by weight. Getting this right is critical: too dry and the mycelium won’t colonise; too wet and bacterial contamination becomes likely.
Step 3: Inoculation
The prepared substrate is inoculated with mycelium – introduced either as fungal spores or, more commonly in commercial settings, as grain spawn (mycelium already growing on a carrier grain like rye or wheat). Grain spawn produces faster, more reliable colonisation than spores alone.
The fungal species selected at this stage shapes the properties of the final material. Commonly used species include:
- Ganoderma lucidum (Reishi) – produces dense, rigid composites
- Pleurotus ostreatus (Oyster mushroom) – fast-growing, widely available
- Trametes versicolor (Turkey tail) – known for structural strength
The inoculated substrate is then packed into moulds that define the shape of the finished product.
Mycelium production harnesses the natural growth capabilities of fungi to create biodegradable and renewable products
Step 4: Incubation
The moulds are moved into a controlled incubation environment – typically:
- Temperature: 20–28°C (species-dependent)
- Humidity: 80–95% relative humidity
- Duration: 5–10 days
- Light: minimal or none (mycelium does not require light to grow)
During incubation, hyphae – the thread-like filaments of the fungal network – spread through the substrate, secreting enzymes that break down organic matter and drawing nutrients inward. Over days, these filaments intertwine into a dense, white mat that binds the substrate particles together into a unified composite. Research published in Mycobiology confirms that temperature is one of the most significant variables in colonisation speed and structural outcome.
Step 5: Deactivation
This step is often missing from general overviews of the process – but it’s essential. Once the mycelium has fully colonised the mould, growth must be stopped before fruiting bodies (mushrooms) begin to form.
Deactivation is achieved by heat-treating the composite – typically at 60–80°C for several hours in an oven or drying chamber. This kills the living mycelium, locking the material into its final form and preventing further biological activity. The result is a stable, inert composite that won’t continue growing or decomposing in normal conditions.
Without this step, the material would eventually fruit, producing mushrooms, and begin to break down.
Step 6: Drying and Finishing
After deactivation, the material is dried to remove residual moisture and reach its target density. Drying time and temperature vary by thickness and application: lightweight packaging foams dry quickly; thicker panels or structural components may require longer cycles.
Finished mycelium composites can be:
- Left as-is for packaging or insulation use
- Sanded, cut, or CNC-milled into precise shapes
- Coated or sealed for moisture resistance
- Laminated with other materials for hybrid applications
Companies like Ecovative Design – one of the earliest commercial producers – have scaled this process to manufacture everything from protective packaging to acoustic panels and leather alternatives.
How does mycelium production compare to conventional manufacturing?
The differences between mycelium production and conventional material manufacturing go beyond the obvious swap of “natural” for “synthetic.” The underlying production logic is fundamentally different.
The trade-off is that mycelium composites currently can’t match polystyrene or aluminium on production speed or mechanical consistency at scale – a known challenge for designers and manufacturers working with the material. But for applications where end-of-life impact and material sourcing are priorities, the comparison shifts considerably.
Environmental considerations in mycelium production
Mycelium’s environmental profile is one of its strongest arguments for adoption – but it’s worth examining specifically where those gains come from.
Substrate: Mycelium requires only organic matter to grow, which means manufacturers can feed the process with waste streams from agriculture and timber that would otherwise go to landfill. A 2021 life cycle assessment published in Sustainability found that fungal-based composite bricks carry significantly lower embodied carbon than conventional alternatives.
Water: Mycelium cultivation requires a humid environment but consumes far less water overall than resource-intensive processes like cotton farming or leather tanning. Controlled growing facilities recirculate much of the moisture used during incubation.
End of life: When mycelium products reach the end of their lifecycle, they can be composted and returned to the soil as a nutrient source – a closed-loop outcome that most conventional packaging materials can’t offer. For a deeper look at how this plays out across a product’s full life, see our piece on product lifecycle assessment.
Emissions: The growth process itself generates no toxic byproducts or harmful emissions. As research in Scientific Reports (2017) notes, mycelium requires only organic matter and produces no waste streams requiring treatment or disposal.
One area worth watching: the energy used in sterilisation and deactivation. While far lower than metal or plastic production, it’s not zero – and as the industry scales, optimising these stages will be important to maintain mycelium’s environmental advantage.
Frequently asked questions
How long does the mycelium production process take? From inoculation to finished, deactivated composite: typically 5–14 days, depending on species, substrate, ambient temperature, and the thickness of the mould. Incubation itself takes 5–10 days; drying adds 1–3 days.
What fungal species are used to make mycelium materials? The most common commercial species are Ganoderma lucidum (Reishi), Pleurotus ostreatus (Oyster mushroom), and Trametes versicolor (Turkey tail). Each produces a composite with slightly different mechanical properties – density, flexibility, and compressive strength all vary by species.
Is mycelium production scalable? Yes, but scaling introduces challenges around contamination control, consistency, and deactivation at volume. Companies like Ecovative and MycoWorks have demonstrated commercial-scale production, and the technology is maturing – though it’s not yet as industrially mature as conventional foam or foam-alternative manufacturing.
Can mycelium replace plastic packaging? For protective packaging, cushioning, and single-use formats: largely yes, and several brands are already doing it. For applications requiring high moisture resistance, structural load-bearing, or optical clarity, mycelium isn’t a direct swap – but it’s a strong candidate for a growing category of applications. See our full guide to mycelium as a material for a complete breakdown of where it performs well and where it doesn’t.
Does mycelium production require special equipment? At small or research scale: no. Basic sterilisation equipment, humidity-controlled incubation chambers, and standard moulds are sufficient. Commercial scale requires more controlled environments and consistent substrate supply chains, but the process remains far less capital-intensive than plastics or metals manufacturing.
1. A Comprehensive Framework for the Production of Mycelium-Based Lignocellulosic Composites (2020) | THE SCIENCE OF THE TOTAL ENVIRONMENT
2. The Effects of Temperature and Nutritional Conditions on Mycelium Growth of Two Oyster Mushrooms (2018) | MYCOBIOLOGY
3. Advanced Materials From Fungal Mycelium: Fabrication and Tuning of Physical Properties (2017) | SCIENTIFIC REPORTS
4. Life Cycle Assessment of Fungal-Based Composite Bricks (2021) | SUSTAINABILITY
5. Fabrication Factors Influencing Mechanical, Moisture- and Water-Related Properties of Mycelium-Based Composites (2023) | SUSTAINABILITY
6. Using life cycle assessments to guide reduction in the carbon footprint of single-use lab consumables (2019) | MATERIALS AND DESIGN
