Making Sawdust Substrate

While most commercial farms rely on supplemented, sterilized sawdust blocks for the cultivation of their wood-loving mushrooms, the process of producing and inoculating them requires the use of a HEPA flow hood, and can be a little daunting for the hobby cultivator.

Luckily, there is a way to prepare a suitable substrate for most wood-loving species utilizing commercially available hardwood sawdust pellets. These are generally marketed for use in woodstoves and can often be found at your local hardware or farm supply store. You can also buy them from us, here!

You will need:

1 Large gusseted spawn bag, with filter patch

6 cups hardwood sawdust pellets

7 cups boiling water

6” length of twine or yarn

2 plastic zip-ties

Add the sawdust pellets to the spawn bag, and CAREFULLY pour boiling water over pellets.

Tie the bag tightly closed with a length of twine or yarn.

Carefully shake bag to mix up contents and evenly distribute moisture.

Allow to cool entirely.

Once cool, cut off twine and inoculate with 1-2 quarts of fully colonized grain spawn. This may be done in the open air without a flow hood or glove box, but work quickly to minimize the amount of time the substrate and spawn are exposed.

Zip-tie the top of the bag closed, fold over and zip-tie again.

Mix up the substrate and spawn very well, and incubate at 65°-75° until fully colonized.