Mycelium Stool (prototype)

Hi! I wanted to share with the community my first attempt at making mycelium furniture. This first prototype is a scaled version of a stool* with wooden legs made with a laser cutter machine. The idea is to scale this up and create a custom mold for the base and also build more robust legs using a CNC machine, that will create a nicer looking stool.

*In this prototype just a box with 4 short legs

Welcome to comment if you've done this before and have some tips or just wanna share some ideas , would love to improve on this!

• Saw dust
• Oyster mushroom mycelium (from a grow kit)
• Big metal pot
• Strainer
• Rubber gloves
• Alcohol 95%
• Plastic container
• Plastic bag

The substrate I am using in this experiment is a mixture of wood dust and chips from a planer. The first step here is to sterilize the substrate as best a possible to avoid contaminants and undesirable spores. To do so, simply rinse using boiling water inside a big pot. After this, remove the excess water by using a strainer. No need to fully remove all the water, just keep a little damp since this will be ideal for the mycelium growth.

Besides sterilizing your substrate, it is really important to also sterilize the container using 95% alcohol which will be used as the base of the stool. It is also recommended to sterilize your gloves as well as any other utensils that might enter in contact with your mycelium mixture. In other words, keep your environment as clean as possible.

In this step I brake down half of the mushroom grow kit (oyster mushroom) and put it inside the metal pot. Next I mixed with the wood dust substrate. The wood substrate should be ideally comprised of relatively large chunks to allow for air to flow within the gaps. The mixing ratio in this experiment was 1:1, however not sure if this is the ideal, more experimentation needed.

Ready to out the mixture in a mold, in this case a used a small plastic box. Just pour it in and do not compress it. For larger molds or customized shapes it is possible to use a vacuum forming machine as seen in videos from Ecovative.

It is also at this stage that I placed the legs for my stool, they are made with 5mm plywood with a laser cutting machine. I place it on top of a 2 cm initial layer of the mixture and then cover it with another 2 cm, as to make a sandwich.

Next step is to put inside a dark bag (we want to avoid light) and keep warm, around 28-29 °C. To keep warm I used one of these small heating floor mat. The highest preset of my mat is 28 °C which seemed ideal for this situation.

Over the next 7 days, the bags needs to be opened daily in order to ventilate and oxygenate the mycelium. It's important here to be careful to not contaminate the mixture by touching it with you bare hands.

I also have one bottle mister with water that I use to keep the mixture humid. I spray a little every day.

On the pictures you can see the progress of the 3rd day. Everything going all right, although the bottom seems to be growing slower than the top surface.

Here is the state of growth during the 7th day. The bottom of the box seems to be less dense than the surface, I decide to remove from the box in order to let air access that area.

After removing from the box I left 2 more days in this state, hoping it will grow more evenly on all faces. However I am a bit impatient and proceeded with the last step which is to bake in the oven for 30 min at 100 °C.

Some of the bits on the top of the stool (from this picture view) are not well attached to the rest of the stool since the mycelium didn't grow as much there, however the bottom is very secure. The overall piece is very lightweight.