AirMycelium produces 100% pure slabs of mycelium — 📷: Ecovative 

Ecovative’s mycelium materials are unique, and always invite plenty of curious questions. One of the most common is about whether our materials will sprout mushrooms, or spread spores that people might inhale or start growing in unexpected places. The short answer is no. But it offers a good chance to talk about some of the basics of mycelium, and demystify the materials we make from it.

Myceli-uh, what?

We work with mycelium, the ‘root structure’ of mushrooms. It’s the webby, fuzzy stuff that grows underneath the forest floor, holding things together and recycling nutrients into the ecosystem. Turn over a log in a forest, and you’ll almost certainly see it thriving under there.

Mycelium is pretty amazing. It’s a living mesh of incredibly thin strands of single cells, linked together into a single cohesive network. The mycelium spreads and branches in search of nutrients, growing with an amazing efficiency and sensitivity to its environment. Learning the mycelium’s preferences for ideal growing conditions is a key part of our technology.

Inside the hollow tubes of the cells, a fluid called cytoplasm flows back and forth containing all the sugars and cellular materials. Outside the cells, mycelia produce enzymes to eat their food and fend off predators. This is why it grows inside its food, which in the case of the strains that Ecovative works with, are agricultural leftovers like woodchips and hemp hurd.

Feedstock for mycelium is poured into growth trays. —  📷: Ecovative 

For the MycoComposite materials, like what Mushroom® Packaging uses, the resulting material is a mix of the mycelium together with its food, which are fused into a strong material perfect for things like protective packaging. With our AirMycelium products, like Forager Hides and Foams, we harvest the mycelium as it grows above its food in pure sheets. These ‘slabs’ of mycelium can then be compressed, heat molded, dyed, sliced, and process in a number of different ways, depending on the application.

None of this involves mushrooms, which are what typically produce spores. When conditions call for it, the mycelium moves to make mushrooms, which produce spores and then drift off to create more mycelium. Mushrooms are sort of analogous to the apples of a tree: they are produced in order to reproduce. Once released, the spores are like invisible seeds that float on the wind until they find a suitable environment. If they do, the spores form little mycelia that grow and start the cycle anew.

Note that the spores only form after the mushrooms do. A key part of our process is to stop the mycelium’s growth well before it even starts to make a mushroom. We love mushrooms, but it’s the mycelium, and the unique structures it creates that we seek to use in our materials. Mycelia form a kind of natural polymer, with all sorts of useful properties such as the ability to repel water, resist microbes, and of course, revert to compost when moistened and added to soil. It also has tissue-like qualities perfect for substituting meat or designing materials with specific grain structures and densities. Once the mycelium has grown through its food, we essentially cook and dry it, rendering the mycelium unable to reproduce while retaining its resilient structure. This means that the mycelium will never get a chance to create mushrooms, and can’t spread its spores. By the time it reaches our customers, the mycelium is an inert, natural biomaterial.

AirMycelium is grown in continuous, large format sheets. — 📷: Ecovative 

All of this is different from something like mold, which raises another common question we get: can mycelium materials create mold issues? Again, the answer is no. Mold works differently from the types of fungi we work with — instead of creating fruiting bodies, mold producing spores straight from the mycelium itself, with microscopic structures called ‘sporangia’. That’s why, when your bread or vegetables get moldy, it spreads fast, despite never seeing any mushrooms.

Every piece of our mycelium materials come from a set of carefully selected source strains, different ones used for different materials. By taking a small part of the original mycelia from our strain library, and growing them in their own sources of food, we can continue working with them indefinitely. The risk of releasing spores into an environment are essentially zero, but we strive to work with our licensees to source strains from their bioregion, which are already tuned to the local environment.

Mycelium is amazing, but it’s unfamiliar to many people, despite being so important to the cycles of life. We believe strongly that mycelium shows us a way to reconnect our ways of life with those natural cycles, and enjoy any opportunity to explain how it works. We also hope to inspire others to learn more about mycelium and fungi — check out our resources page for more info and in-spore-ation!