Three Things You Should Know About Spalted Wood
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Three Things You Should Know About Spalted Wood

Meet Dr. Javier Ribera of Empa Swiss Federal Laboratories for Materials Science and Technology, a Switzerland company. Discover what spalted wood is as well as three interesting facts about it.

Podcast Topics

  • History of spalted wood use in the United States
  • Three kinds of spalting: zone lines, pigmentation, and white rot
  • Mel & Mark Lindquist’s legacy of spalted wood in woodcraft
  • DIY spalting methods: the possibilities and limitations
  • The mycology of zone line spalting: what species are involved? 
  • What does wood anatomy have to do with spalting?
  • How researchers, such as Dr. Ribera, at Swiss Federal Laboratories for Empa Materials Science and Technology are commercializing spalted woods
  • How you can spalt your own wood at home!

Spalting Basics to Know

Spalted wood is beautiful. It’s a form of rotting, and it’s caused by fungi. Spalting comes in many forms: patterns, colors, textures. Until this century, the biology of spalting wasn’t well understood, and even less so any methods to produce it in a laboratory setting. We are once again joined by Javier Ribera, a wood materials scientist and mycologist from EMPA to discuss new research on spalted wood. The team at EMPA has built off of existing literature on the biology of spalting which has allowed them to artificially produce spalted wood, potentially opening a market for designer wood rot.


1. Fungi are behind these beautiful organic designs

Fungi work behind the scenes, and unless they fruit a mushroom, their effects on their surroundings are often overlooked. Spalted wood is a prime example of fungal activity that goes unnoticed. A broad range of spalted wood admirers are unaware that the brilliant natural colors or gorgeous striations are a result of fungi's metabolic activity in these woods. 

Let's not forget to thank our fungal friends next time we get to enjoy these natural wonders!


2. Spalting comes in many colors and patterns

For those of us who are fans of wood spalting, we generally just think of one kind: zone lines. These are the what the familiar black lines are referred to in most spalted wood craft. However, there are two other types of spalting that are just as interesting! 

Another form of spalting is known as white rot. This is when a fungus digests the lignin in the wood, leaving behind cellulose which results in a 'bleached' look. This kind of spalting is often called marbling, and it's gorgeous!

There is also pigmentation spalting, where a species of fungal can change the color of their woody substrate. They come in blues, greens, pinks, reds, oranges, browns, blacks, yellows and purples. Some colors are more rare than others, with blue being one of the most popular.


3. Science is figuring out how to cultivate spalted wood

Featured on the podcast episode about this, we have Dr. Javier Ribera who has been researching how to spalt wood in a laboratory setting with his team at EMPA. Current methods still rely on natural systems such as burying wood with inoculated wood chips or spores, and wait for spalting to occur. This can take up to 3 years, and isn't well controlled. 

The team at EMPA is defining methods that are reproducible and controllable. They have even been able to to induce zone lines for custom line patterns! Listen to this episode to learn more about how they are achieving this.


Podcast Show Notes & Works Cited



Transcribed by ** Subject to error

Alex 0:00
You're listening to the mushroom revival podcast.
Lera 0:07
Hello, friends, it is 10pm on August 16, I'm supposed to take a lift to the airport to go to telluride in six hours. So getting this podcast in before I head on the road, so I can edit in the air. And I still have to pack so I hope I get to see some of you there, that would be super great. Alex is already there, which is why I will be flying solo on this episode. And our guest doesn't have a whole lot of audio to contribute to this specific topic. So it's just gonna be a lot of me rambling, maybe a little less fun and dynamic. But I think you guys will like this short program on what's Baltic. So let's let's get into it. Today we're talking about wood rot, specifically decorative rotting, known as spalted. Wood. No, those beautiful patterns of black lines are color variations and some specialty furnitures Yeah, that's a fungus, or more accurately funguses. So last week, we spoke with Javier Rivera, a wood material scientist and mycologist at Ember and Switzerland, which has such unique fungal biotech going on at this is not the first or last time you will hear about them on the show. Last episode, we discussed their myco word research where they were able to engineer the acoustic properties of wood using fungi and today we're pivoting to more visual aesthetics where really for the first time, researchers are describing methods to commercially produce this artisan and also coveted spalted wood.

Listeners. If you like the show, and you want to keep this content coming, Your support will make or break it. You can easily support us by reading and reviewing and even more so by visiting our website and using this surprise coupon code ***** for a surprise discount off of our decadent functional mushroom products. Now, back to the show. before knowing it was fungi and getting into fungi, I've always loved spalted wood I thought it was gorgeous. So for the listeners who don't know what spalted wood is, could you define it?

Javi 2:47
Yeah, sporting is. Any form of food coloration goes by fungi, as balding is divided into three main types, like pigmentation or white rot and also its own lines.

Lera 3:01
So spalted wood is a term used to define any word coloration due to fungal decay. In the field. There are three main categories which consist of pigmentation. This manifests like a stain and you get blues and pinks, reds, greens, Gray's blacks, browns, I've also seen yellows and lilacs but those are way less common. Secondly, there is white rot, often from tummies versicolor, aka turkey tail where the wood becomes essentially bleached due to the fungus digesting the fibers that gave it the color that it once had. And finally, there are zone lines which encompass what most of us probably think of when we think of spalting. It's likely my favorite kind of spalting. And it's when two genetically distinctive individuals encounter one another on a shared log or substrate. And at least one of the fungi involved in spotting excretes in abundance of melanin, right at the point of recognition that there is another fungus. And it's this concentration of dark melanin that makes those beautiful illustrations. Another term for this is battle traces. And you can think of these zone lines like a wall that says, This is my side and this is your side. So words can have one or all of these forms of spotting, and if it does, woodworkers refer to it as marble rot. Super cool. This wood is gorgeous. And I encourage you to poke around the show notes for some lovely photos of this phenomenon, especially if you're thinking to yourself What the hell is she talking about? I've never heard of spalted wood. It's super gorgeous. I'm curious for a lot of people in the lumber industry how much they know about the mycology of spalting or do they just cut it it looks pretty. They sell it you don't I mean and and is They're much research on the species the mycology of what is going on in this spalting? Or is it very sparse? Because it's estimated that 5 million species of fungi are out there in the world. And we've only classified 120,000. And I would guess that we're finding new spalted species almost every day with the amount of log and logging that's going on. But my guess is a lot of these loggers don't really know they say, oh, cool colors and lines, but they're not classifying the different species. Is that correct? Or is there a breadth of knowledge on on this, this research?

Javi 5:45
Yeah, this is what we are trying to do in our project, we are trying to get a consistent method to make spalting because, as you said, this is it has been very wild so far. So nobody knows exactly what's going on, or how to do that in any control way. So now, we are basically working with with beech wood, because in Switzerland, this wood has been traditionally used for heating systems. And by using this wood and giving the wooden additional value, we could gain up to 10 times its value. So this means that we can gain some of the markets for wood that was kind of disposed.

Lera 6:39
So despite this word, Rarity and beauty. Once upon a time spalted wood was considered a defect in the timber industry, and any infected word would be reduced in value and deemed unfit for whatever purpose and Europe However, spalted word was not only acceptable, but appreciate it during this era, in the mid 1900s. But on the stolen land that we call the US of A spalted wood was, I guess, just a nuisance in the lumber field. And it really wasn't until a man named Melvin linguist, an American woodworker, who found some of this wood on his property in upstate New York, and from that point, had gone out of his way to find it almost exclusively work with spalted wood. For all of his creations. Mel made art he made furniture. And he especially like to turn this stuff so cheap put it on a lathe, which is a tool that spins really, really fast and allows you to make perfectly round bowls, plates, tools, or any other cylindrical form you can think of his work was so good, and he was so respected as a woodworker, that his choice to work with spalted wood was somewhat of a catalyst to this new decorative industry and an already niche market. Right. The demand for the spalted wood was high enough that it became a worthy endeavor to try and figure out how to farm this stuff. And if you guys are interested in this story, there is a two hour documentary on YouTube that I watched for this episode. And the link will be in the show notes. It's with a wonderful scientist who spent her PhD studying spalted wood and I'm Sarah Robinson, and she interviews the son of Mount Mr. Mark Lindquist, heir to the task of how to farm spalted wood, and he attempted at home productions of spalted wood by simply burying uninfected wood with shavings of infected wood. And for all intents and purposes, it worked. This method of burying wood and inoculating with spores or other infected chips is pretty much as technical as it gets for spalted wood production. To obtain spalted wood today, a large amount of that is due to chance, which is not that different from mushroom hunting. In fact, if you see a fall in love with mushrooms fruiting from it, and you chopped it into you probably find yourself gazing at a piece of spalted wood. Mushrooms are after all, an indicator for those who seek the sculpt. So it's hard to come by hard to grow yourself. And it takes years to form whether it's in the wild or in your DIY burial pit, it can take up to three years to grow out so mines to match what is on the market already. So this commodity, it's unpredictable and it's slow moving. And these are not adjectives that describe a scalable product even if it is in a niche market. So here's where empathy comes in. The research showed that you can shorten the timeframe to a mere five to 10 weeks to get spalted wood and they were able to apply some degree of control as to where within the wood the spalting occurred. pretty freakin cool. But to do this They needed a deeper understanding of what exactly spalting is what is actually happening in spalted wood Javi and his team and Emma are researching the phenomenon by defining the array of exact fungal species involved in spalting. The Anatomy of the wood that it infects the process of formal decay and so many other things that I'm not going to list off, but just trust me when I say that these people are rigorous in scrutinizing this process, okay, okay, okay. Okay, now we're going to get a bit more psychological. There are many fungal species that result in spalting. But again, what is actually happening here? Well remember the three types of spalting that we mentioned, each kind has its own unique myco logical activity. So we've got those own lines folding this kind of spalting, in my opinion, is the most interesting in the simplest of terms, it's when two fungi don't play well together.

As stated before, to genetically distinct individuals, that can be two different species, or of the same species, but different enough of a strain that their mycelium doesn't fuse. So if you can't join them, beat that, right, huh, I'm joking. Actually, I see these onlines as a myco, logically civil way among fungal communities for resource acquisition and communal development. And these these zone lines are described biologically as a marker of antagonists ation, but could it be a sign of tolerance, and coexistence? I mean, when the zone mines are created, the different fungal communities don't dare cross those lines, they let one another be in those compartments without coming over and overthrowing one another. I mean, it's, it's a step up from what us humans do to one another. So these lines, they look like lions, right? But that's really not the whole story. They're, they're more like bubbles or cages within the word, the lions, they're three dimensional markers. They define spatial compartments for a given community of fungi, the fungi are so good at this isolation, in fact, that if you took a sample from a given compartment, you'd be growing an isolated fungus. I mean, it's, it's pretty cool. And zone lines, they don't just protect fungal communities from one another. They also protect themselves by influencing the moisture content. And by counteracting the tree's immune system, if it happens to still be alive. Also pretty cool. I mean, this shield of pigment is maintaining a moisture level. It's fighting off a plant's immunity. And it's keeping competitors at bay. I mean, this is like a little, like a little shield of melanin and insulation and a wonderful material for the fungus. And you know, it's no wonder that this pigment has manifested in an array of species. I mean, this shows up in times of fungal stress, not just in woody substrates, but in space and Chernobyl and in entomopathogenic, fungi, it's everywhere. And one other feature that I want to highlight about zone lines is that this occurs in a phase of spalting are rotting, known as incipient decay. So this is before the wood has begun to like truly rot away, which is why you can make stools and bowls and you know, actual structure out of spalted wood because you can catch this decay before it ruins the structural integrity. So who is behind these zone lines? What species is doing this? The answer is a few. However, the malaria polymorpha, or dead man's fingers, is very common to find in spalted wood, it's actually the only species that has been identified to create some of those zone lines without an antagonist. So it could just be word and malaria polymorpha. And you could still end up with those spotted striations. This is one of those species that is melanized under any kind of environmental stress, not just when there's another fungus present, and they have to, you know, establish their boundaries, but with other species, you likely won't be getting these zone lines without some level of fungal confrontation. So this is a pretty great breakthrough for the spalted wood industry is sale area, you know, you can use this one fungus to sculpt your wood. So now that we have a super basic idea of what spalting is, the scientists at Ember are asking the question, can you induce zone line formation? And imagine if you could, you could create your own patterns. You could write your name or draw a map or whatever kind of creative application you could think of. One method underway for control zone lining involves strategic placement of the inoculum Be it plugs or spray. But basically you allow the fungus to grow in a controlled temperature with moisture levels at about 30% and an opaque tub with water or moist vermiculite. And with that simple method, they have been able to encourage spalting to be in certain regions of the wood. But that's not very precise in terms of lining. So an alternative approach is to artificially induce zone lines by using copper sulfate, which is a fungicide, and will clearly cause stress to the fungus that it's encountering. So this stuff can be applied locally to an infected piece of wood to essentially draw those own lines on the surface. And this worked pretty well with malaria polymorpha. And while this approach doesn't result in 3d displays, what mo was able to achieve on the surface of the wood was pretty darn cool. Check out the publication in the show notes to see a panel of their sewn line induced patterns. And there's one more species we have to highlight in terms of zone learning that is, oh boy

crucher Marissa do star I, that's definitely not how you pronounce it, but it's 1030. And that's, that's gonna have to do, let's just call it by its pedestrian name, brittle Cinder, which just looks like a very distinctive, grayish whitish, poly Porsche crusty type of fungus. Anyway, Emma is considering the mechanical strength of the wood, they intentionally rot, right? When you're writing stuff, what's going to change, the mechanics are going to change. And spalting as we talked about is incipient decay. So things haven't really started breaking down just yet. But it still changes the mechanics, this other fungus, brittle. Cinder apparently, is exceptional at not only spotting the wood, but maintaining the structural integrity, you know, getting the the zone lines that you want and losing very little of the mechanics of the wood. It also grew faster than malaria. And this particularly worked well with beech maple. And they tried it with some other common hardwoods and had success as well. But yeah, I mean, it's worth noting that spalting can go too far and become spongy. And then like, you would not want to take that into your woodshop and try and turn it on a lathe or do any sort of woodworking with it, it would probably just fall apart. Okay, and then what is happening with these pigments. So have you all ever seen blue stained wood, it's typically very few and far between. But what my experience is, I'll be in the woods, and then just, there's one log, all by itself. It's just this beautiful, brilliant blue color. So it's quite a treat to stumble upon. And boy, is it blue. I mean, if this stuff is truly one of the bluest blues that you can find occurring naturally, there's a multitude of blue stain fungi but the one that Emma has focused on and the one that seems to be kind of a go to for this type of spalting is korach borea, or rugen essence. It's the elf cup, blue stained fungus. It's quite common. It's rare to see mushrooms off of this log. And the few times that I have seen these mushrooms are really really tiny. I mean, it's like the size of in like sunflower seed size at least. That's the biggest that I've personally seen. So picture any old decaying log, pretty unremarkable in terms of color, right? But coracle Borya Wow, it leaves its trace and it is just a gorgeous blue. And in this one, what's going on here so it's not like there's an antagonist This is going to occur whether it's coexisting with other fungi competing with other fungi or not, right. inside of this fungus there is melanin just like the other spalting species. But there are other pigments as well. And it appears definitively blue, not due to the pigments but how they're situated in the hyphae. So the hyphae itself turns blue. Apparently, I've put this on agere before and saw mixed things. But it's cool nonetheless. And this stuff is robust. There are wood based arts that use this blue spalted wood from the 1600s and that pigment remains intact today. You can still see that blue color on the wall. It I mean, it's amazing. And to add to this level of badassness in the fungus, a pigment called sai lindian, is currently being explored in Opto electronics for organic semiconductors. More on that in a future episode. But the point is, these fungal pigments are so much more than what meets the eye. And it's cool that there is something to meet the eye, right? So much of the myco illogical magic is in perceivable. by us, it's it's too small, you know, they're they're behind the scenes all the time until you get this big, juicy bullet that turns blue and you cut it. I mean, that's wonderful. But there's so much more mycological activity, vaulted wood, you know, we're seeing remnants of its metabolic activity and markers of its existence on the substrate.

Alex 20:51
Do you have a favorite type of spalting?

Javi 20:55
I really like one of the patterns we are doing right now. Because our approach to doing this project is to control the way that fungi are spalting the wood so we can place different fungi in different parts of the width. And we can make straight lines, or maybe more wild patterns. Or maybe we can bleach some parts, but not the others. So in this regards, I think we could in the future, we could have kind of tailor made furniture or veneer vertical where the client could say, I like it more bleached, or I like it more while with very strong and dark lines or maybe thinner lines. And we could even achieve double lines. So where you could see both lines going together one each other. And I think this is a great result. Because as I said before, I don't think this is that under control so far. But if we can do that, I think, yeah, the sporting field will will

Unknown Speaker 22:12
benefit a lot. And this is something that you're trying to commercialize.

Javi 22:16
Um, that's a good question. It is now working together with an industrial partner, he will have the license and the rights over the whole project and the products there. So the technology will be transferred completely to him in the next couple of months. And Davies Yes. After the upscaling production, he'll be able to sell these these would.

Lera 22:48
And there's so much more we could say about this topic. But for those of you who really want to dive in, got some great show notes. And guess what you can try this at home. I have a link where you can purchase a sporting pack from mossy Creek mushrooms, as well as a source from Northern spalting. However, it appears you have to be a member to make a purchase. But hey, if you are a mushroom farmer, or you're played around with mushrooms, and you're like, I want to try assaulting some wood, you can do that. Thank you for listening to me ramble about spalted wood for so long and big, big thank you to Javi Riviera for all the time and resources, publications and just great conversation that we have had. And finally before we say goodbye, our review choice of the week since we started doing this is from sameena 21 subject beautiful voices for the fungal Kingdom review. Thanks for speaking up for those beings that don't have a voice but are so important for humanity and the planet. So much wisdom. It is clear both of the hosts are passionate and super knowledgeable. I heard Alex speak in person when he was on the east coast and I could tell he had a special connection to the mushrooms. Thank you. So Mina, thank you. It's great that you got to see Alex speak in person. Perhaps we will see you at telluride perhaps we'll see you at another mushroom event. We really appreciate so so much you took the time to leave a review. It's gonna keep this going. We are just so happy that mycology fungi, mushrooms, funghi fungi is becoming a socially acceptable thing to talk about. And a topic of interest. Anyway, that's a wrap. Thanks again for listening to me ramble for this long and as always, much love and maybe spores to be with you.
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Alex Dorr

Alex Dorr is the founder and CEO of Mushroom Revival. He launched Mushroom Revival with a mission to revive health with the power of mushrooms.

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