Growing Mycelium Materials at Home

I have made mycelium based composite materials. The mycelium is the binder to the substrate, creating a homogeneous material. The purpose of this project is to bring attention to new developments in sustainable materials and to encourage experimentation from the public.

500g sterilized chopped straw

50g oyster mushroom grain spawn

one 15l container

ten 500ml containers or moulds of your choice

The first step is to prepare the substrate so the mycelium can grow. The mycelium requires water to grow and gets it from the substrate. To do this fill your 15l container two thirds of the way with straw. Then add water until the straw is covered, you may need to push the straw down to do this.

Leave the straw to soak for up to 2 hours. Then drain any water that hasn't been absorbed by the straw.

Roughly break up the grain spawn into small chunks and add it to the container. Mix thoroughly.

Loosely place the lid of the container on so some are can flow through and leave the container in a dark warm and humid place.

Check on the container every few days. Once a thin white mat has grown over the surface it is ready for the next step.

Take chunks of the inoculated substrate and loosely break it up before placing it in your 500ml containers. Lightly compress the substrate in these.

Repeat this for all the containers.

Once all are filled, loosely place all the lids on like we did for the large container and stack them in a warm, humid and dark place where they can grow.

If you'd like to produce samples of different shapes then you can fill moulds in this step instead of containers, just make sure the moulds are sufficiently sized in each dimension so the straw fits easily.

The samples should take 1-3 weeks to grow completely. Check on them every few days. Once they are completely covered in a mycelium felt-like skin they are ready.

There are many options for processing the samples. The goal is to remove all the water content to prevent rot and further growth. The way I chose to do it was by hot pressing each sample at 3kN of pressure, 90 degrees Celsius temperature for 10 minutes. I then placed each sample in an oven set to 50 degrees Celsius for half an hour to remove the remaining water.

If you don't have access to a hot press then going straight to the oven step is fine, you will just end up with a more foam like sample.

Now you have your materials, please use them how you see fit and share in the comments your findings!