How to Make an Incubation Chamber for Grain Spawn: DIY Mushroom Incubator
One of the biggest hassles for new mushroom growers is maintaining ideal temperatures during the colonization phase. This crucial phase takes place just after inoculation of grain spawn and is important not only for the mycelium to rapidly gain a foothold on the nutrient-rich spawn material but will also significantly cut down your total colonization time. So in this article, we will be building a DIY Mushroom Incubator, similar to the MycoBROODER™ Mushroom Incubator. If you would rather save your time and purchase this awesome incubator, you can support his business by buying directly from them here.
UPDATE: We ended up swapping the heat mat for a full-size heat mat due to the amount of time it was taking to heat up the chamber. See the end for the steps we took to modify the full-size mat.
Materials Needed:
- 19-quart plastic storage container with a gasket lid (19.5 x 11.75 x 7.75 inches)
- 8-watt heat mat
- Digital LTL heat mat controller
- Custom-cut grill or wire rack or cooking rack
- Ziptie and Sticky Squares
- Rubber Grommets – We used the 1.5 in Jandorf grommet from Ace Hardware, and a 5/16″ grommet for the temperature probe.
Note: you will also need various tools such as a 1 1/4 hole saw or adjustable hole bit and a hand drill.
Prepare the Container:
Choose a plastic storage container with a gasket lid. MycoBROODER uses a 19qt opaque bin, however, we prefer transparent so that we can see the progress without needing to open the container. The container should have outside dimensions of approximately 19.5 x 11.75 x 7.75 inches. Ensure that the container is clean and free of any debris.
Drill holes for the heat mat and temperature regulator:
For our build, we drilled a 1.25-inch hole in the bottom left of one side of the container for the heat mat power cable and a 5/16-inch hole in the top right of the same side for the heat probe.
Once both holes are drilled, insert the top grommet.
Install the Heat Pad
If your heat pad has a power regulator like ours does, you have two options. The first is to roll the heat pad tightly and cram it through the hole we drilled. This is by far the easiest, but definitely not the prettiest as you will have a large bundle of cable and the regulator dial messily ziptied to the front of the incubator. The second option is to splice the wire and reconnect it, which we will not cover and is not recommended unless you are familiar with working with cutting and reconnecting electric cables.
Once the heat pad is inside the tub we will cut the grommet which holds the cable in place. Carefully cut the grommet, open it to insert cable, then secure it in the hole. See the gallery below for these steps.
Place the custom-cut grill or wire rack inside the container, above the heat mat. The grill or rack should be elevated to allow proper air circulation around the jars or bags. This helps maintain an even temperature throughout the incubation chamber.
Integration and Setup:
Next, we will insert the temperature probe through the hole we drilled in the top of the container. I mounted the probe near the top using a zip-tie and a sticky square.
At this point, we are technically done, but having loose cables is a real eyesore. So we will fold up the excess cable and mount it to the outside of the box using sticky squares and zip-ties. Not the prettiest thing, but it does the job. See the gallery below.
Finishing up:
Set the desired temperature range on the heat mat controller between 74°F and 82°F. This temperature range is ideal for colonizing PF Tek, Grain Spawn jars, bags, or culture plates.
Place the grain spawn jars or bags on the custom-cut grill or wire rack. The 19-quart chamber can hold up to 11x – 1 quart Wide Mouth Ball canning jars or bulk substrates of up to 10 pounds.
Secure the gasket lid onto the container, ensuring a tight seal. This will help maintain consistent temperature and humidity levels inside the incubation chamber.
And that’s it. Let us know if you build this out. We would love to see your build.
UPDATE: The smaller reptile mat was taking longer than we would like to heat the chamber. So we ended up using a standard heat mat. In order to use the larger mat we had to splice the cable because the temperature adjustment dial was too large to fit in the 1.5-inch hole we drilled. Below is the process we took to modify the mat.
