Simeon Goodwin


Nutritious & Delicious food for Mushrooms!

Substrate is the surface from which mycelium and mushrooms can grow.


Inflated Clean Room - Rob van der Burg is cooking the straw substrate for the 3D printed canal house.

Substrate is the technical term for the base on which one can grow flowers, mushrooms and algaes.

At Mediamatic the most common substrates we use are

Straw (Hay)
Coffee Grounds & Waste
Seeds & Grain (For Making Spawn)
Husks (Chaff)

The type of substrate you should use depends mainly on the type of mushroom you intend to grow.

For example

Shiitake and Schizophyllum like to grow on fallen trees in the wild, so they prefer to grow on wood based substrates such as sawdust and wooden dowels which contain all the nutrients they would find in the wild.

Oyster mushrooms also grow well on wood in the wild, but we have a lot of success growing the mushrooms on coffee waste.

Reishi in the wild prefers to live on dark, damp forest floors. Coffee grounds are also quite a good substrate for reishi.

Making a good substrate is like making a good dinner! In order to make the best meal for mushrooms, the best ingredients need to be added.

Additional Ingredients include

Vermicculite - This absorbs water and nutrients like a sponge , and slowly releases it, like weetabix!

Chalk - Kalk - This reduces the acidity of the substrate and is useful in coffee ground / grain substrates.

Once you have mixed a delicious substrate, you should place it in jars or filter bag. This must be sterilised to ensure any bacteria inside the substrate is killed.

When growing oyster mushrooms, this is not always necessary. Fresh coffee is usually sterile enough to grow oyster mushrooms. Straw / Hay need only be pastuerised. This means cooking at 70 degrees Celsius and kills only the bad bacteria.