Mycelium composites

Also known as Fungal composites, Mycelium-based composites, Mycelium bio-composites

Mycelium composites are light materials made by growing fungal threads through agricultural or wood waste and then drying the result in a mould. Laboratory studies show workable stiffness, fire screening results and shaping options, but strength, moisture resistance and environmental benefit depend on the specific formulation and use.

Research and prototypesDemonstratedReviewed 21 Oct 2026
AI illustration · Illustrative scene, not a photograph of the specific device or experiment.

In plain language

Mycelium is the network of fine threads, called hyphae, that a fungus grows. If the fungus is given a fibrous material such as sawdust, straw or coffee waste and kept in a controlled space, the threads grow through the material and bind the particles together. The shaped object is then dried, which stops further growth.

The result is a light solid that is part fungus and part the material it grew through. Makers can change its density and shape, and can add plant fibres to change its behaviour. Research so far has produced lab samples and prototypes. These suggest possible uses for light, insulating or sound-absorbing parts. They do not show that the material can carry building loads, and 'grown' does not automatically mean low-impact, fire-safe or compostable.

Technical explanation

Mycelium composites are made by inoculating a fibrous substrate with a fungal culture. The hyphae colonise the substrate and form a network that holds the particles together. In a 2023 study, Kohphaisansombat and colleagues grew Pleurotus ostreatus on spent coffee grounds for 28 days, at about 27 to 30 degrees Celsius in darkness and 70 to 80% relative humidity, with 10%, 20% or 30% pineapple fibre added as reinforcement. The samples were then dried before testing. Growth conditions, humidity, feedstock blend and mould geometry all influence the final structure.

Structure varies with position in the growing material. Olivero and colleagues (2023) grew a mycelium tissue for about nine days on agricultural feed and sliced it into layers. The layers nearest the feed had a higher crosslink density and a higher micro-indentation modulus than the youngest layer. Crosslink density fell by about 65% from the oldest to the youngest layer, and the micro-indentation modulus fell from about 55 kPa to about 26.5 kPa. Indentation was carried out on two separate tissues. Separately, Kaiser and colleagues (2023) filled knitted textile tubes with a mycelium paste, called Mycocrete, which stayed in place as permanent formwork. Their flexural modulus was about 90 MPa, compared with about 5.6 MPa for a sawdust-based mycelium composite tested in the same study. Removing the knitted formwork reduced mean strength and Young's modulus by 14% to 50%.

Fire behaviour depends on the fungus, the feedstock and the test method. Jones and colleagues (2018) measured pure mycelium of Trametes versicolor using pyrolysis combustion flow calorimetry (ASTM D7309). They reported a peak heat release rate of 67 W/g, lower than the 446 W/g they reported for PMMA, and about 23 wt% char at 600 degrees Celsius. The authors list flame spread and smoke toxicity as fire risk factors yet to be quantified. In the 2023 spent coffee ground study, no small sample ignited during a 30-second alcohol-lamp exposure, although the flame-exposed area charred. Water absorption of the 28-day samples was about 100% to 114%, so moisture control, coatings and long-term wetting and drying tests remain open questions.

What the evidence says

Each statement is typed by the strength of its evidence and linked to the source that supports it.

Demonstrated Shown in a published experiment, test or shipping product.

In a mycelium tissue grown for about nine days on agricultural feed, micro-indentation modulus fell from about 55 kPa in the layer nearest the feed to about 26.5 kPa in the youngest layer, and crosslink density fell by about 65% from the oldest to the youngest layer.

Sources: [1] · Results: micro-indentation and SEM analysis · medium confidence

Laboratory composites of Pleurotus ostreatus grown for 28 days on spent coffee grounds, with 10% to 30% pineapple fibre, had compressive strength of 1.65 to 2.92 MPa, density of 0.28 to 0.36 g/cm3 and water absorption of about 100% to 114%.

Sources: [2] · Table 1 (28-day samples)

In small-sample alcohol-lamp tests, the spent coffee ground composites did not ignite during 10, 20 or 30 seconds of flame exposure, although the flame-exposed area charred. The authors state that fibre content did not significantly influence fire-resistant properties.

Sources: [2] · Flame test results · medium confidence

Mycocrete, a mycelium paste made with beechwood sawdust and other ingredients and grown within knitted textile formwork, had a flexural modulus of about 90 MPa, compared with about 5.6 MPa for a sawdust-based mycelium composite tested in the same study.

Sources: [3] · Results: mechanical testing (Table 4) · medium confidence

Removing the knitted formwork reduced the mean strength and Young's modulus of the BioKnit mycocrete by 14% to 50%, and without the formwork the samples cracked completely and lost all strength after failure.

Sources: [3] · Results: mechanical testing · medium confidence

In pyrolysis combustion flow calorimetry, pure mycelium of Trametes versicolor had a peak heat release rate of 67 W/g and about 23 wt% char at 600 degrees Celsius, compared with 446 W/g and 0 wt% char reported for PMMA.

Sources: [4] · Pyrolysis combustion flow calorimetry results (Table 2) · medium confidence

The authors of the 2018 fire study list flame spread and smoke toxicity as fire risk factors yet to be quantified, and tested a single mycelium species.

Sources: [4] · Discussion and limitations

The BioKnit team built a 1.8 metre high freestanding arched dome prototype from seven knitted modules filled with mycelium paste.

Sources: [3] · Prototype description

Speculative An idea or possible use. Not evidence of anything.

Growth conditions could in principle be used to vary density and stiffness within one panel, but this has not been demonstrated for a full-size component.

Sources: [1] · Results: micro-indentation and SEM analysis · low confidence

Limitations and open problems

  • Properties vary with substrate, growth conditions, moisture and batch. The sources reviewed do not give a verified batch-to-batch production specification.
  • Most results come from small laboratory specimens, a limited set of growth conditions or a single prototype. The sources reviewed do not report tests on full-size building components.
  • Strength is low for many formulations. The 28-day spent coffee ground composites reached 1.65 to 2.92 MPa in compression, so any load-bearing use needs further testing.
  • Water absorption is high in the spent coffee ground composites, at about 100% to 114% after 28 days. Coatings may be needed for humid use, and coatings can change fire behaviour and end-of-life options.
  • The fire tests in the sources are screening or small-sample tests. They are not a building-material fire classification, and the 2018 study did not quantify flame spread or smoke toxicity.
  • Environmental benefit is not established. Feedstock collection, sterilisation, growth control and drying all use resources, so a life-cycle comparison needs a stated functional unit and the alternative product's full life cycle. This profile does not give verified life-cycle figures.

Possible future uses

Speculative

Ideas, not predictions. None of these has been demonstrated.

  • Replaceable acoustic panels grown in reusable moulds.
  • Protective packaging shaped to the outline of a specific object.
  • Non-structural interior panels or insulation made from regionally available agricultural residue.

Product concepts: Mycelium packaging foam

Timeline

  1. 4 Dec 2018Jones and colleagues publish fire-property measurements of pure mycelium and mycelium-biomass composites in Scientific Reports. Sources: [4]
  2. 14 Jul 2023Kaiser and colleagues publish the BioKnit study, using mycelium paste grown within permanent knitted textile formwork. Sources: [3]
  3. 7 Nov 2023Olivero and colleagues publish a study linking growth-direction structure to local stiffness in a mycelium tissue in Scientific Reports. Sources: [1]
  4. 19 Nov 2023Kohphaisansombat and colleagues publish online a study of mycelium composites made from spent coffee grounds with pineapple fibre reinforcement, in Mycology. Sources: [2]

Futures this could help bring about

AI illustration
How far away?

Materials that grow and repair themselves

Engineering prototypes · 4 of 8 steps done

Related breakthroughs

Glossary

Mycelium
The network of fine fungal filaments that grows through a substrate.
Hypha
A single filamentous fungal thread. The plural is hyphae.
Substrate
The material that supplies nutrients and physical structure for fungal growth.
Micro-indentation
A small-scale test that presses a fine tip into a material to estimate its local stiffness.

Sources

  1. peer reviewed paper
    Gradient porous structures of mycelium: a quantitative structure–mechanical property analysis
    Eric Olivero, Elzbieta Gawronska, Praveena Manimuda et al.. Scientific Reports, 7 Nov 2023. DOI: 10.1038/s41598-023-45842-5. Accessed 21 Oct 2026.
  2. peer reviewed paper
    Fabrication of mycelium (oyster mushroom)-based composites derived from spent coffee grounds with pineapple fibre reinforcement
    Chatchai Kohphaisansombat, Yanisa Jongpipitaporn, Pitak Laoratanakul et al.. Mycology, 19 Nov 2023. DOI: 10.1080/21501203.2023.2273355. Accessed 21 Oct 2026.
  3. peer reviewed paper
    BioKnit: development of mycelium paste for use with permanent textile formwork
    Romy Kaiser, Ben Bridgens, Elise Elsacker et al.. Frontiers in Bioengineering and Biotechnology, 14 Jul 2023. DOI: 10.3389/fbioe.2023.1229693. Accessed 21 Oct 2026.
  4. peer reviewed paper
    Thermal Degradation and Fire Properties of Fungal Mycelium and Mycelium - Biomass Composite Materials
    Mitchell Jones, Tanmay Bhat, Everson Kandare et al.. Scientific Reports, 4 Dec 2018. DOI: 10.1038/s41598-018-36032-9. Accessed 21 Oct 2026.

Revision history

3 changes since this profile was created.

Changes on 21 Oct 2026
Published on owner instruction (content loop iteration 2)791aabe
Sources and claims re-checked against originalsfbb434c
Initial profile drafted from Codex research note and primary sources0eba374