Use Cellulose Filter Discs

How to use Forest Fungi reusable cellulose filter discs to make grain spawn, reducing plastic and your footprint, growing gourmet mushrooms sustainably. Reusable Cellulose Filter discs are great for use with Ball Mason jars for making grain spawn. Ball Mason jars come with a two piece lid.    


Drill between one and three holes in the lid. Hole sizes can be between 2 - 10mm. The holes are drilled into the lids to allow air exchange but prevent moisture loss.

Filter disc and lid

Place your Reusable Cellulose Filter disc in the screw top lid, any side up.

Filter Disc into lidFilter Disc in lid

Then place the lid which you have drilled the holes in on top of the filter disc. The lid can be placed in either way however some say it can go rusty if placed with the rubber seal facing the filter disc. For this reason we place the rubber seal down towards the glass jar as shown in the picture below.  

 Place in drilled lid

You can also use Cellulose Filter Discs on other jars however you might have to cut them to size and use silicone to glue them on. Forest Fungi Filter discs are reusable and are a great way to reduce plastic usage in growing mushrooms.

Screw lid on top 86mm Filter Disc on jar