I'll admit it. Every time I walk through a grocery store, I notice the plastic: clamshells around berries, film around cucumbers, trays under nearly everything. So when I came across new research out of the University of Maine, I got excited. Researchers there have created a plastic-free food packaging material made from mushroom mycelium and wood fibers. It resists both water and grease, and it breaks down once it has done its job. Let's take a closer look.

The Problem With Plastic

Plastic is popular for good reasons. It's cheap, lightweight, flexible, and very good at keeping food fresh. But concerns about what's in it have been growing. According to the UMaine report, a recent study found that more than a quarter of the roughly 16,000 chemicals used to make plastic pose risks to human health. Then there's what happens after we toss it. The United Nations estimates that 19 to 23 million tons of plastic make their way into rivers, lakes, and oceans every year.

Caitlin Howell, an associate professor of bioengineering at UMaine, said it well: "Plastics are very good at what they do, but then again so were forever chemicals and lead in paints and gasoline. It sometimes takes us a while to understand the long-term impacts of the things we invent, but the good thing is that when we do, we can change."

The challenge is finding something that works as well as plastic without the baggage. That's where our fungal friends come in again.

Two Natural Materials, One Clever Combination

The new material brings together two ingredients that each do one job really well.

Cellulose nanofibrils (CNFs): These are tiny fibers of cellulose, the natural polymer that gives plants their structure, and these ones come from wood. UMaine has worked with CNFs for years because they resist oil and are biodegradable.
Mycelium: This is the root-like network of threads that fungi grow beneath the mushrooms we see and eat. Mycelium naturally resists water, which is why it has turned up in everything from leather alternatives to bricks.

Put them together and you get a coating that keeps out both water and grease, the two things food packaging has to handle. Howell put it simply: "Nature has solutions, and as humans, we can look at and adapt to those solutions and better fit it in with our ecosystem. We don't have to choose plastic."

How You Grow a Package

The fascinating part about this solution is that it isn't about manufacturing so much as cultivating.

The team grows the fungus ahead of time, then blends it with a malt extract broth that gives it extra nutrients. The CNFs go into that mixture too. Blending breaks the hyphae, the tiny branching filaments that make up a fungus, into small pieces so they grow back evenly. From there, the mycelium does what mycelium does. It grows and works its way into the gaps between the fibers. "Basically, we try to mimic what they need in nature," said Sandro Zier, the chemical engineering Ph.D. candidate in Howell's lab who led the research.

The wood fibers do double duty here. They're food for the mycelium, and they also add their own grease-resistant barrier. Once the coating has grown and dried, it's only about 20 to 25 microns thick, roughly a quarter of the thickness of a human hair.

The same process can go two ways. It can coat a material like paper, or it can form a standalone film of just CNFs and mycelium. That film is slightly fuzzy on one side and feels like plastic on the other. I'd love to get my hands on a piece to check it out firsthand.

Why Turkey Tail?

For this project, the researchers chose turkey tail (Trametes versicolor), a fungus that grows on decaying trees in the wild even here in East Texas. If you've walked through the woods and seen those striped, fan-shaped brackets on a fallen log, you may have met it.

The choice makes a lot of sense. Turkey tail already makes its living breaking down wood, so it can feed directly on the wood-derived CNFs. Similar fungi have even been used to bind particle board together. Anyone who has grown mushrooms on logs or wood-based substrate knows how happily these fungi take to wood.

From Weeks to Days

One of the biggest hurdles with mycelium materials has always been time. "Traditionally when you grow mycelium materials, you need weeks to get anything that you can use," Howell explained. Zier and the team cut that weeks-long process down to just three days.

They're now working on scaling up. Right now production is measured in square centimeters per hour. By adapting the method to common industrial machines, they hope to reach square meters per hour. Zier is working with a team of undergraduate researchers on a roll-to-roll system, the kind of continuous process used to make paper and film, which would bring the material much closer to commercial use. Better scale also means lower cost, and the material is already inexpensive to make.

What It Means (and What It Doesn't)

Before anyone expects to find mushroom-coated packaging on store shelves next week, let's keep our feet on the ground. This is still research, and the team is still refining and scaling the process. But the promise is real. A material like this could be:

Biodegradable: Made from fungus and wood, it decomposes once its job is done instead of lingering for centuries.
Water and Grease Resistant: It handles the two biggest challenges in food packaging without plastic.
Low Cost: The ingredients are cheap, and scaling up should make it cheaper still.
Fast to Produce: Three days instead of weeks makes mycelium materials far more practical.
Versatile: It can coat paper or stand alone as a film.
Food Friendly: As Howell noted, "The nice thing about fungi is that we already eat them, so we know that they're going to be safe for us long-term."

Howell also sees this as a door opening to something bigger: "Maybe we don't need the fungus to grow through everything. Maybe we can just use it on the top as a layer. I think it opens a whole lot of new avenues for creating sustainable materials."

Fun Facts About Mycelium and Turkey Tail

Named for Its Looks: Turkey tail gets its common name from its banded, multicolored rings, which resemble the fanned tail of a wild turkey.
Nature's Recyclers: Wood-decay fungi like turkey tail break down dead trees and return their nutrients to the forest floor.
Networks of Every Size: Mycelial networks can be anywhere from millimeters to miles across.
The Mushroom Is Just the Tip: The mushroom you see is only the fruiting body. The real organism is the mycelium, a web of threads called hyphae.
A Material of Many Talents: Mycelium is being explored for leather alternatives, bricks, building materials, insulation, and now food packaging.
Even Computers: If you missed it, we recently wrote about how researchers are using mushroom mycelium as electronic memory in Can a Mushroom Remember? The Weird World of Fungal Computing.

What Stood Out To Me

Zier said something in the interview that has stayed with me: "If I go into the ocean, I see plastic. If I want my children to go into the ocean, they shouldn't see it anymore."

That's a future worth working toward. And I love that part of the answer might be growing quietly in a lab dish, or on a fallen log in the woods. Mushrooms keep surprising us. They feed us, recycle our forests, and now they might help wrap our food without leaving a mess behind.

I hope you enjoyed this look at the latest fungal breakthrough as much as I enjoyed digging into it!

Source: University of Maine News, "Researchers use fungus to create plastic-free food packaging"

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