(inquisitive music)
- Can I show you something?
- [Cory] Yeah, whatcha got?
- It's a mushroom brick.
We actually made a brick out of mushrooms.
I'm pretty happy with it. (giggles)
- [Cory] And why do you have that?
- Well, there's actually this whole movement of researchers
and engineers and architects who are all looking
for a more sustainable building material.
Right now, the construction of new buildings accounts
for more than 1/10 of all the world's
annual carbon dioxide emissions.
A lot of that comes from the materials used,
things like cement, which is responsible
for pumping out almost four times as much CO2
as the entire aviation industry.
So we just really need alternatives.
- [Interviewer] And we're gonna solve that with mushrooms.
- Well, we made this brick because we wanted
to check out the whole process, foraging for a mushroom,
growing it in a Petri dish, all the way to stress testing.
Oh shoot.
- [Cory] I think it's okay, it's okay, it's okay.
- [Justine] We wanted to see
what mushrooms are really capable of.
- [Cory] And how did all that go?
- So...
(keys clicking) (inquisitive music)
To start, we needed to find a mushroom sample.
I don't know the first thing about mushrooms,
so I found someone who does.
- This is the gem-studded puffball,
and it's edible when it's white in the inside.
And this is a deadly toxic mushroom called
the destroying angel, if you eat this, you will die.
- [Justine] This is William Padilla-Brown.
He knows a lot about mushrooms.
- I have cultivated over 35 species of mushrooms,
cordyceps militaris, tolypocladium ophioglossoides,
grifola frondosa, hericium erinaceus,
hericium americanum, pholiota adiposa.
Geez, there's so many Latin names,
it's hard to always remember all of them.
- [Justine] We drove out to the forests
of Pennsylvania to enlist William's help
finding the perfect mushroom sample.
He's a regular in these woods.
- I spend a lot of time in the forests
collecting various organisms, bringing them back to the lab,
getting to understand their DNA intimately,
experimenting with them
for potential medicinal or culinary value.
- [Justine] William focuses most of his research
on the cordyceps militaris mushroom.
- [William] Which are an entomopathogenic fungi
which means they grow on insects in the wild.
- [Justine] He published the first
English handbook on its cultivation.
- Now there are people cultivating cordyceps,
which has been really exciting to watch the process
of that happen from like my bedroom
to houses and farms all around.
- [Justine] Wandering through the forest foraging for fungi.
This wasn't always the case for William.
- I grew up in cities, I never,
trees weren't even like a thing to me.
It was just like background colors.
My brain didn't recognize natural patterns whatsoever.
- [Justine] Then William had an epiphany.
- Am I allowed to say like whatever?
- [Justine] A mushroom-related epiphany.
- And I went in the woods and I started to realize
that I'm connected to all of this.
I started to find the really interesting,
unique, delightful aspects of the forests.
And then after that, the passion that I developed
around natural ecosystems drove me to dive
into a better understanding, which I found through science.
- [Justine] After a short hike, he led us to this tree,
a black locust, and growing on that tree.
- [William] Phellinus robiniae,
the cracked cap polypore mushroom.
It's a beautiful specimen here.
- [Justine] William says
this is a great species for building with.
- This mushroom is very hard and corky,
and the mycelium will retain some
of those properties as well.
I'm not gonna take the whole thing down,
that'd be disrespectful, I'm just gonna take a piece of it.
So Corky, should be enough.
- [Justine] This tiny snip of mushroom was
our starting point, back at William's lab,
he dropped even smaller tissue samples
into some agar, basically food for the mycelium.
- [William] And we only need like a tiny piece
of the mycelium to make this grow out.
- And with a few Petri dishes in tow,
we headed back to New York.
Next, we needed to grow the brick, which took some time.
Some of our samples molded,
and some of them didn't grow much at all.
But we got a couple samples with clean mycelium fibers.
That's all this white stuff on the Petri dish.
Mycelium is like the roots of a tree.
They snake out seeking food,
and form a fibrous network throughout the forest.
The dense crisscrossing mycelium fibers gives it
its strength, so we wanted to grow the mycelium
and coax it into a useful shape.
This part was tedious.
Move the fuzzy gunk into a small jar full of grains.
Wait a week, move the results into a bigger jar
full of sawdust pellets and soybean hulls.
Wait another week, cram that all into a mold
in the shape of a brick, wait another week,
and hope all the while that the mycelium
inside keeps growing denser and stronger.
So if you're paying attention, that's over four weeks.
So while we waited, I called up David Benjamin.
- Hi, how are you?
- [Justine] He is an architect who sees a lot of potential
in mycelium as a green building material.
- It's a great moment to be exploring it.
- [Justine] In 2014, David built a tower
out of mycelium bricks as a way
to showcase mushrooms' potential.
And it went on display in New York City.
- We ended up creating a pavilion
that was about 40 feet tall, the actual thing
that we made this new architecture out of is a new kind
of brick out of agricultural waste and mycelium.
- [Justine] After that, he got even more ambitious
for another exhibit in Paris.
- For this one, we deliberately kept
the building blocks alive in a way that we could put
two bricks, or two blocks, next to each other,
and in just the right conditions, they would grow together.
- This might look and sound kind of bizarre,
but mushroom bricks actually have a lot going for them
compared to more polluting building materials.
You don't need to burn fossil fuels to produce them.
And when you're done with them,
they don't leave behind a toxic mess.
- We could make architecture by kind of growing
the building block materials, then make a structure,
and then at the end of the useful life,
return that structure, all those materials,
back to the earth instead of having them sit
in the landfill for hundreds or thousands of years.
- [Justine] More than a month after our trip to the woods
with William, we had a mold full of mycelium.
We popped the material out of the mold and into the oven.
Baking it on low heat for a few hours
stops the mushroom from growing, and finally
(oven beeps) mushroom brick.
I was just surprised by how light this is.
It almost feels like a piece of wood, I guess?
(knocking on brick)
Yeah, it does kind of sound like knocking on wood.
It is cracking a little bit.
Hey, I've never made a brick out of mushrooms before.
I don't know anyone else who has, so I'm impressed.
So what should an eco-minded designer do
with a brick like this?
Building an entire structure would be ambitious.
Mushroom bricks alone are not as strong as concrete.
So this means a stress test
for two other really promising uses.
We got some help for this bit too.
- Yes, there we go, I think I got the settings good, okay.
- [Justine] Sonia Travaglini is
a mechanical engineer at UC Berkeley.
- I think it's gonna be amazing.
And you know, a lot of these tests are really
the first sort of experiments you do
help you understand intuitively
what these materials can do.
- The first is a strength test.
To use our material as infill
for walls that aren't load-bearing.
Mycelium used this way wouldn't have to hold anything up,
it'd just have to carry its own weight.
So we're gonna do a DIY compression test.
We're basically gonna stack these 38-pound cinder blocks
on top of the mushroom brick to see if it squishes.
- [Sonia] Impression tests are really good to understand
how much weight or how much force
a material can withstand until it squishes.
- [Justine] Did it squish?
- [Sonia] This is more of a sort of rough-and-ready,
perhaps preliminary test, just to see if you're
in the right ballpark figure of strength.
- Last one, please don't fall on my foot.
Is it squishing a lot?
Let's take it one step further
and get some more weight on there.
Nice.
Next up the chocolate test.
How well could mycelium insulate a building?
- [Sonia] So I would recommend doing this outdoors
and with plenty of PPE. (giggles)
- [Justine] On one side of the brick, a chocolate bar
that melts at around body temperature,
on the other side, a blowtorch.
You can see where this is going.
Here we go.
- The easiest way to see if something will go
on fire is to set it on fire.
- [Justine] Oh man, I think this thing is catching fire.
My team is ready, all right, oh shoot.
- [Cory] I think it's okay, it's okay, it's okay.
- You know what, the chocolate is not even soft
after 20 seconds of direct heat, a flame,
a blowtorch, on this side of the brick.
The other side of the brick is unharmed,
and so is the chocolate.
- [Cory] That thing is really smokin'.
- Yeah, I think we gotta put it out.
All right, thanks for donating your water, Cory.
(keys clicking) (soothing music)
There's a long way to go to develop
mycelium building materials further
to make sure they'll perform as well, if not better,
than the stuff they're replacing.
Meanwhile, other people are working
on making clothes and even leather-like shoes
with material made from mushrooms.
Mycelium also turns out to be a good alternative
to plastic, and styrofoam, and packaging.
There are so many possibilities.
William sums it up well.
- Fungi are some of the most ancient
and most resilient organisms,
they've survived every single mass extinction,
and they've been here for the longest time,
and they hold that wisdom.
I feel as though nature gave us everything we need
if we look in the right places.
- Thanks to Lexus for their support,
be sure to check out the new 2021 Lexus IS
by going to lexus.com/is.
Their campaign is about going all in
on your passion and getting a greater reward,
which is why they've sponsored this series
on researchers and innovators.
They don't influence our editorial,
but they do help make productions like this viable.
So thanks again to them, and thank you for watching.