In the Future, Leather Will Be Made From Mushrooms Not Cows

Bolt Threads is the biotech company best known for its Microsilk, a synthetic spider silk that’s made through fermentation with just water, sugar and engineered yeast. It’s completely sustainable, and it looks and feels exactly like traditional silkworm silk, but it’s also significantly stronger. (Last year, we called it “the fabric of the future.”) Today, Bolt Threads has introduced its second material, Mylo, which is a synthetic leather whose main ingredient is mycelium, a fungus found in the root structure of mushrooms.

Unlike Microsilk, there’s no fermentation or yeast involved in the making of Mylo. Instead, it’s grown in large, environmentally-controlled warehouses, much like how the mushrooms you buy at the grocery store are grown. The mycelium is placed in large pans with corn stover (the ground up biowaste of corn, like the stalk), which the fungus eats and grows. Under the right conditions — humidity, temperature, CO2, oxygen and water volume — the mycelium grows into a soft foam, which is actually a network of very small fiber. Then it’s sliced into sheets, cured and put through a tanning process. The end product looks and feels very much like leather. It has comparable durability, strength and suppleness, too. The one aspect of Mylo that has surprised Dan Widmaier, Bolt Threads’ cofounder and CEO, is that fabric is really abrasion-resistant.

Bolt Threads is still early on in the development of Mylo, but they’ll release a handhag in June that’s made entirely of the synthetic leather. There’s also a collaboration with Stella McCartney in the works. In theory, Mylo could be used in any product — wallets, keychains, bags, shirts — that traditionally use leather. Like natural leather, Mylo can be dyed and will patina over time.

“In a planet that’s going from seven billion to 10 billion people, and a vast increase in middle-class consumers who want to use their disposable income to buy purchases to make their lives more comfortable, better, faster,” said Widmaier, “we don’t have enough space to make enough cows to make enough leather. We think there’s a need. People have a long history with leather. They love and enjoy it. And I think there’s a future where there’s no way to make enough to fill demand — finding ways to make a fantastic product that can fill that gap for the future is really important.”

“People have a long history with leather. They love and enjoy it. And I think there’s a future where there’s no way to make enough to fill demand — finding ways to make a fantastic product that can fill that gap for the future is really important.”

The modus operandi of Bolt Threads has been to use research and technology to create new materials for a sustainable future — and Mylo fits that bill. Making traditional leather is essentially a three-year process. It takes time to raise the cow and take care of the land it needs to eat. With Mylo, it’s a technology-driven material that takes a few weeks to grow. No animals are harmed in the process. The land, too, isn’t harmed by fertilizer and upkeep. And it’s all environmentally friendly.

Also unlike Microsilk, Mylo is a joint effort between Bolt Threads and Ecovative, a company who has been using mycelium for decades to create sustainable packaging solutions. Think an environmentally-friendly styrofoam for shipping a flat-screen TV. Mylo is a more refined foam that’s grown in much more carefully-controlled conditions, and it’s also grown in corn stover rather than wood chips. “[Evocative] mostly focus on mycelium packaging and they figured out the basis of growing the foam and then Bolt is taking it to the Mylo material and the consumer products category,” said Widmaier.

“There’s a ton of potential here,” said Widmaier. “This is the challenge and I think we talked about this before, and Bolt will have for a long time, is for anything that we make, the scale that we could be at is much bigger than where we’re at today. And so we want to make more of this, put this in the hands of people. We think it’s going to surprise a lot of consumers. It’s going to solve a real problem in the world around resource sustainability.”

Bolt Threads’ first Mylo bag will be available for pre-order this June. If interested, you can sign-up here to be alerted on its availability. Also, Stella McCartney will debut the Mylo Falabella Prototype 1 at the Victoria and Albert Museum’s “Fashioned from Nature” exhibit, which will open to the public on April 21 in London.

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