Grow Architectural Models With Mushrooms





Introduction: Grow Architectural Models With Mushrooms

Mushrooms are actually the reproductive system of the organism mycelium, so technically this project is about growing mycelium into any form you want, in this case an architectural model.

Since mycelium grows by consuming carbon rich materials like wood chips, straw, cotton, etc, the shape that it will grow into can be organized by stuffing a formwork with mycelium food.

Disclaimer: If mishandled, pressure cookers can be dangerous. Additionally, in letting things decompose there is the a potential for unwanted bacteria or fungus growth. Attempt at your own risk!

Step 1: Get Mycelium

There are a few different ways to get mycelium. Of course it grows naturally in the wild and you can grow your own through propagating spoors or through tissue samples. Both of these methods are kind of involved, so I'm not going to cover them in this instructable.

An easier option is to buy ready grown mycelium online, for example:

You can also sometimes find "spent" mycelium blocks at mushroom farms for free and revive them by breaking them up and adding new substrate. Because these blocks have been growing for a while there is more risk of bacterial contamination, nevertheless, I've had a lot of success with this method. Even the mycelium in the block with the shriveled up mushrooms has the potential of being revived, but the fresher the better.

If you want your model to grow really fast and you've purchased a fresh block, you can skip the next two steps and just break up your block and pack it around your form. However, if you're recycling blocks or you want to get the most out of the mycelium you've purchased you can add more substrate.

Step 2: Sterilize Your Substrate

While I've used a lot of substrates including wood chips and coffee grounds, the carbon based mycelium food or "substrate" I usually use is straw. Straw is a waste product available very affordably in bale form at feed stores and race tracks. Chop some straw into small pieces, cover it with water and sterilize it in a pressure cooker for an hour. Once the pressure cooker is cool enough to open, wash your hands, clean all work surfaces and implements with rubbing alcohol, and drain the straw in a clean strainer. Cool to 75 degrees and use immediately to reduce the potential for bacteria exposure.

Step 3: Inoculate the Substrate With Mycelium

Wash your hands again and break up the mycelium block you've purchased or scavenged into small pieces. You don't need a whole block for such as small project, so you can save the rest of the block for another purpose. Mix these pieces in with your chopped straw and try to distribute them evenly throughout the mix.

Step 4: Design Your Formwork

The formwork can really be anything in any form that you want. I've used plastic, plexiglass, 3d prints, etc. The mycelium will grow into, or begin to consume organic materials such as wood, which can be useful for some applications, but not very convenient if you're trying to extract your formwork later. For the formwork above I wrapped the pieces of plywood with clear tape to prevent this from happing.

Step 5: Place the Substrate

Pack the substrate and mycelium around the form. The tighter it's packed the smoother the final product will be. Mycelium takes on whatever form and surface you present it with, so packing the substrate against smooth materials such as plexiglass or plastic will result in a smooth finish.

Step 6: Seal It Up

I use a plastic bag welder to seal the model up completely. Mycelium needs oxygen to grow since it consumes oxygen and expels CO2, like us. You can buy special bags for growing mycelium that come with a welded in filter strip that allows gas exchange, but does not allow bacteria to get in. I find that I'm growing the models so rapidly that keeping bacteria out is not a high priority and I just leave a very tiny hole for gas exchange. If the bag is sealed up with enough moisture you won't need to mist it during the growth stage. Store the model in a cool (55-75 degrees) dark place to discourage bacterial growth.

Step 7: Let It Grow

I usually let the mycelium grow for a week or a week and a half. If you let it grow too long it will eventually fruit mushrooms. Once this has happened there are potentially mushroom spoor on your model and in theory, given the right conditions mushrooms could start growing again. If you start to see green or black spots, your substrate has become contaminated with bacteria and should probably be composted.

Step 8: Remove Form

Once the model looks sufficiently covered in a white mat, you can halt the growing process. At this point you don't need to worry about contamination anymore, so you can just cut open the plastic bag and remove the form. Because the mycelium is moist it is still pretty fragile, so remove the form very carefully.

Step 9: Bake Your Model

Preheat your oven to 200 degrees F and bake your model for 45 minutes. This will effectively kill the mycelium and prevent any further growth. It will also dry out your model create a sturdy final product.

Step 10: Add Scalies

Add some architectural scalies (scaled figures) and you're done!



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    20 Discussions


    I am doing a research on architecture and biomimicry, especially Mycelium products and would like to use it to make my architecture formwork.

    The method looks great from your pictures!

    Although I am confused where to buy the basic material, Mycelium, from.

    I checked the Farmwest Fungi site, should I go for mushroom minifarms? Or if it is Fungi Perfecti site I guess I did not find the exact mushroom I should get for this project! The Ecovative site seemed less confusing, where they have a GIY mushroom bag worth 20$. That lets one to make mycelium in a clear bag provided by them and takes around a week to grow. But I am not sure if I should go through the entire process(Reactivating the dry material+Let's Grow something) or stop by the first step(Reactivating the dry material), then add the straws( as sterilized in the pressure cooker mentioned by you) and stick it up on my formwork ? I am sorry for asking such basic things as I am really confused and I have no previous background in dealing with fungus before but I really want to get this right.

    The link for the step by step process as per Ecovative manual on GIY kit -

    And I have to mention - Thank you for sharing this! It sparked a new way of making things!

    Bracket and shelf mushrooms that grow on living trees are usually tough and traditional Appalachian crafters carve them into all kinds of things.

    I am curious how strong this is. If you drop it, will it break? Would it hold up against a preschooler? It's cool even as decorative object..

    1 reply

    It's very resilient and will not easily break if dropped. However, it does not have a really hard surface and could be carved into with a sharp object.

    Love this!

    We're growing a chair from Pycnoporus coccineus - check out our blog post series: Living organisms, a secret room and a chair

    1 reply

    That is a great color; I can't wait to see your chair! Unfortunately, Pycnoporus coccineus does not grow in Californa, but apparently some other Pycnoporus do–I'll be on the lookout.

    I studied Architecture many years ago and went through several techniques of building models - but this is about the most crazy and outstanding approach to architectural model I ever saw and I like it! I do doubt though that one could "build" some very intricate structures this way such as steel framework etc. but for more organic designs like free concrete cave forms this is the appropriate way of display. Thanks for this 'Ible

    Outstanding! Bio-3D printing, I love it. You've used it for architectural modelling here but the same proces can be used to make all sorts of items. As jim_lewis1 pointed out there was once a project to make custom fit packing the same way that failed because the process takes too long but like anything the uses are only limited by our imagination.

    I will have to give this a go, thanks. :)

    although our initial reaction might be 'yuck' it's not much different from using the dead parts of plant material, IE wood. I have seen this used as grown to fit environmentally friendly transport packaging. Shame that hasn't taken off more to reduce all the plastics used in that.

    Cool instructable.

    I don't know whether this has a practical application in the real world, but it would be really cool as an art form.

    This must be similar to how Ford is making car parts like arm rests.
    The baking was the step they didn't cover on Public Broadcasting.
    Looks like a dip in some rubber or plastic coating will make these last a long time.

    2 replies

    I do not want to buy ford then if that is true. I do not know how I would feel about having mold in my car. Is this safe?

    This is root material. Mycellium is not mold.
    Baking absolutely kills the organic matter.
    Totally safe. It's organic. :)

    Guess i am getting a new way to grow my warhammer 40k terrain!

    It's not mold. It's mycelium. If mold starts to grow on it you throw it out. Once you bake it nothing grows on it. Cool project.

    I do not know how I would feel about having a mold in my walls, haha

    Haha, yeah, I know it sounds strange. Once you bake it, it is inert and if you bake it before mushrooms grow and spoor then you've basically eliminated the possibility of regrowth. I'm not going to say that there is absolutely no risk, but it's probably safer than having toxic, outgassing foam in your walls!