Mushroom leather and how it is made (2020) | Hacker News Reader

Mushroom leather and how it is made (2020)

watsonwolfe.com

148 points_Microft68 comments

I think mushroom leather is a cool invention, but at least at the present time, the vast majority of animal leather is a byproduct of food production, to the point that there is a surplus of leather because people like hamburgers more than leather products: https://qz.com/1308051/the-popularity-of-sneakers-is-leaving...

I've always had a hard time reasoning about this.

On one-hand, it's a waste-stream, which means that finding a purpose for it means that the resources gone into the animals from which leather is made become more efficient.

On the other, if you believe that meat production at its current scale is bad for the environment, you're making it cheaper and subsidising it.

Then there's the impact of all the chemicals involved in leather tanning, which are not inconsequential.

I don't know what to think about leather in all honesty.

It looks to be 1-5% of the value of the animal at this point but some are just discarded entirely.

It's important to consider the durability of leather products. IME, good quality natural leather products easily last 3-4x longer than alternatives.

The tanning process isn't exactly environmentally friendly, but it doesn't have to be if it can reduce overall consumption by enough.

Indeed. Good leather products can last for years or decades. Leather belts, wallets, shoes, bags, etc all last far longer than their fabric alternatives.

Centuries, if cared for properly.

Bad quality, leather, on the other hand, disintegrates within a few months.

I was at the Apple WWDC, where they passed out those leather jackets with the big blue "X" on the back.

Mine didn't make it to the next WWDC, and I took great care of it.

I think that they may have had a couple of versions of the jacket. I saw it reappear, for quite a while, on the bodies of Apple favorites (I wasn't one), for many years.

What do we know about the durability of mushroom leather and how does its environmental impact compare with animal leather?

One wonders how the total life cycle of cotton or nylon compare to the leather production process. Mushroom leather could be used when the look really matters, but otherwise I would think a lot of leather products could be made with heavy canvas or nylon.

Anyway I am a vegan so using animal skin as an industrial output is something I think we should make a conscious effort to end as much as possible.

Leather is also a byproduct of dairy production! Many may relinquish their hamburgers, but few will relinquish their pizzas.

One must consider the cow a miraculous piece of technology: an efficient reactor for converting cereals and grasses into valuable fats, proteins, as well as useful materials.

One more complicating question -- does the hide value of an animal incentivize better treatment during its life?

Leather itself is a driver of deforestation and not just a secondary byproduct.

https://www.stand.earth/publication/forest-conservation/amaz...

The point being that if you shrink the leather market you don’t really reduce the cattle market at all and what would be made into leather is just discarded.

If you cannot sell the leather, the meat will have to become more expensive (same cost to raise the animal, additional cost for discarding the skin, less income). If meat is more expensive, less will be bought, shrinking the meat market.

Yep. Let's return back to times when only rich and wealthy were able to afford meat.

If the price for alternatives goes down in return, sure. Tax meat more heavily, subsidize vegetables and plant-based alternatives with that tax, or come up with some other clever scheme. It'll drive change a lot faster than just depending on the few who (can) care enough.

We eat, on average, too much meat as it is, and with meat the negative externalities such as deforestation are completely ignored in the price.

reading the post about medieval jobs, I don't think this time ever existed.

It depended on the climate and society. Pastoralists living on the steppes almost exclusively lived off animal meat and dairy products, while folks in areas with heavy grain production were much more likely to get the vast majority of their calories from staple grain crops.

I don't know about medieval times, but a lack of animal products in the diet of the the impoverished and imprisoned was a problem as recently as the early 1900s. The disease Pellagra[1] is caused by a lack of niacin in the diet, which can be commonly found in animal products (and certain plant products like legumes). It was considered a paupers disease and was most commonly found in rural areas and in the poor, imprisoned, or orphaned. The prevailing theory was that it was related to eating corn - either an insect born illness or a contaminant - when in reality it was a lack of diet diversity in the people who could only afford to eat corn. The history on Dr. Goldberger is actually really interesting and I recommend a skim of his Wikipedia page.

[1] https://en.m.wikipedia.org/wiki/Pellagra#History

Subsidizing a bad thing so more people can do it doesn't make it a good thing. I also eat meat, but the main argument here is "let's have meat prices more accurately reflect the cost and let the market adjust accordingly", and then as a bonus it should also help the planet and everyone

A great point, and I think an important thing to note about mushroom leather is it is ALSO a byproduct of food demand! It is (or was, at least initially) made from the waste of commercial oyster mushroom farming.

Why alternatives to leather matter:

Nowhere to hide: how the fashion industry is linked to amazon rainforest destruction [0]

[0] https://www.stand.earth/publication/forest-conservation/amaz...

Also: https://news.ycombinator.com/item?id=29433500

Edit: fix yelling

Has anyone found out how the mycelium is treated after harvesting it? Does it need to be 'killed' before being used? Is the leather like texture embossed onto it or are there mycelia that develop similar structures all by themselves?

There do not seem to be any obvious drawbacks. Could it actually be that we discovered a new type of material for building things or clothing that had been overlooked so far?

Anything biodegradable (in the composting sense) almost always does not last long absent significant chemical treatment. If you think current faux-leather technology is a step down from the real thing, then mycelium based products will be even worse. There is an inherent trade-off between biodegradable and long lasting products. What we can do is make products that are recyclable. In other words, engineer materials to only break down with a specific brand of artificially engineered enzymes that are not found in the wild. Unfortunately we are still a couple years away in terms of proteomics advancement to be able to do de novo synthesis with such precision.

This is a false statement. Animal leather is also biodegradable. Durability of both comes from tanning.

I did say with the caveat of chemical treatment.

While true, you also said mushroom leather should be even worse than the real thing; I wouldn’t know for this specific product, but once you allow for chemical processing all bets on relative ranking are off.

https://bcgctest.files.wordpress.com/2018/03/gs_2017_mycowor...

This has an interesting set of tanning processes, but it's funny how SEO saturated this topic is. There are some video results that are probably useful, but 99% of my searches are turning up commercial garbage, and nothing to do with actually making mushroom leather.

Iirc from a podcast, sodium carbonate is used to soak amadou mushrooms for a felt-like material, which Paul Stamets uses for his hat.

You'll probably need to learn the jargon and terms of art specifying the exact types of mushroom fabrics and materials that can be produced.

Good luck!

Good find, thanks!

We’re an investor in MycoWorks.

The mycelium (root structure) is killed in the process. It can then be tanned as you would tan normal leather. MycoWorks is working with Hermes which tans the leather in their own tanneries.

Animal leather is also embossed actually and they emboss the mycelium leather the same way. It’s an incredible fabric that looks and feels like animal leather, but it can also be grown thicker and to shape. It’s very versatile. An incredible product.

Thanks for your answers! Maybe you could answer this one as well? The size of the mushroom material is most likely only limited by the size of the vessel that the fungus is grown inside, isn't it? That is, it becomes possible to produce larger pieces than they could be made from animal skins/hides?

Indeed. https://www.scientificamerican.com/article/strange-but-true-...

That's quite fascinating. Are any products making use of this aspect available? A form-fitting leather phone skin would be quite luxurious I imagine.

Thanks for chiming in!

Tanning, historically, is quite a chemical-rich and polluting process. Is the tanning process similar for myco leather?

I don't know anything about this mushroom leather, bit I do know that a lot of real leather also has texture stamped onto it.

Real, "full grain" leather (the only kind that includes the external surface layer of the hide, is rather smooth. You have to look pretty closely to see the texture, though you will see some imperfections like scars if they aren't sanded away in processing.

Most of the pebble like texture or wrinkled texture you see on leather products is stamped.

One of the things I love about leather is it’s extreme durability!

I’ve been wearing the same leather boots for 4 winters now, a leather jacket is steadily approaching the 10 years marks.

More generally: sustainability problems can be mitigated or solved by buying stuff that lasts, see for instance /r/BuyItForLife

Is mushroom leather as durable?

It's nice having durable products, and frustrating when things succumb to unnecessary failure. I think that given the externalities of producing it, though, it seems increasingly short-sighted to look at that metric in isolation.

What about durability per hectare of dead forest or kilo of CO2?

Though I'm quite fond of leather shoes, I'd gladly take a slightly less durable product that's many times less harmful to produce.

> less durable product that's many times less harmful to produce.

A big citation needed here… I am not sure boots made from locally-sourced leather are less sustainable than boots made from synthetic fibers and petroleum derivates some place in South-East Asia.

Citation needed for what? I don't think such a product exists yet.

I was talking about the calculus of how you appraise products.

> locally-sourced leather

Transportation costs are negligible compared to the direct and indirect impacts of raising cows

https://ourworldindata.org/explorers/food-footprints?stackMo...

> A big citation needed here…

Oh the irony...

That link about beef explains what, exactly?

> the direct and indirect impacts of raising cows

Uhm, and this is relevant to discussion because…

I am sorry but I don’t really get it.

I have a biker leather jacket since 20 years ago. Still as good as new.

I just wonder how something like canvas compares. If it lasts 1/2 as long but nothing had to be killed and skinned it's kind of hard to compare the two. But canvas comes from plants, which seems nice. Mushroom leather, if it did not compare directly to animal leather, could be used in decorative applications, while durable plant based or synthetic materials could be used when longevity is needed.

I find that, for leather sneakers and boots, the soles often wear out and the rest still looks new.

Makes me miss the old days of going to the cobbler to get new soles put on.

Some shoe brands still do this, such as Allen Edmonds:

https://www.allenedmonds.com/discover/our-story/recrafting.h...

Recycled rubber and plastics aren't inherently safe. They can contain lots of toxins.

I'd prefer just the shrooms, sans the crud.

https://www.theguardian.com/us-news/2019/jun/25/lawmakers-co...

If it can be grown around mould/shape then one could make 3D print of their feet to grow perfectly shaped shoes..?

Yes. A while ago an artist did this for a mouse:

https://www.hisour.com/victimless-leather-27501/amp/

https://www.artnews.com/art-news/news/biotechnology-as-art-f...

In my country traditional craftsmen used tinder fungus to make hats and bags.

I wonder how this holds up under sunlight. One of the problems with leather is drying and cracking.

That's a good question. Leather requires you use polish to keep it in shape. I wonder if this mushroom leather requires the same, and if so, whether regular polish can be used.

The mycologist Paul Stamets wears a hat made of this leather. He has to be careful around fire because of the flammability, it's made from tinder fungus after all.

Try Kombucha leather

This shroom leather is so 2000 late. Call me when you've got E. coli and Lactobacillus leather ready.

Not sure why this is downvoted, kombucha leather is a real thing: https://www.instructables.com/Kombucha-Fabric/

It is probably downvoted for the lack of context.

(The link you posted doesn't really show that kombucha leather — rather than a piece of fabric for arts and crafts — is a viable thing either.)

By definition, leather is "animal skin treated in order to preserve it, and used to make shoes, bags, clothes, equipment, etc" So, there is no such thing as mushroom leather. Maybe a mushroom leather substitute.

>Mushroom leather is an environmentally friendly material because it can be treated without using polluting substances. At the end of it's life, the material is completely biodegradable and compostable.

I think that is true for real leather, too.

> can be treated without using polluting substances

I’m not an expert, but from some prior research it seems like the tanning of real leather involves chemicals that would create pollution as a byproduct.

In the US, they are probably fine to call it "mushroom leather".

You can say a product is made from imitation leather, faux leather, plastic leather (or pleather), etc... I believe only the use of unqualified leather would be deemed as deceptive by the FTC.

I believe the treatments in leather prevent it from composting compared to unprocessed animal skin.

I wonder if these could be useful materials to grow on Mars.

I like how they mention the mushroom leather shoes are "gluten free", I guess in case you need to boil them for food during a famine...

Well boiling them could yield a rich umami broth and certainly satisfy some late night vegan cravings.

Nothing like the taste of mushroom leather marinated in leaded city gasoline exhaust. :-)

It seems to be a kind of silly "virtue signaling" at this point. Reminds me of fat free gummy bears and sugar free fatty products.

I thought most leather products are too poisnous to eat.

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