What is a mushroom fruiting chamber and how do I build one?

A mushroom fruiting chamber is an environment designed to facilitate the fruiting or reproductive stage of mushroom growth, where the mushroom develops and produces fruiting bodies (such as mushrooms) that can be harvested for consumption. It provides the ideal conditions for mushroom growth, including temperature, humidity, and fresh air exchange. Fruiting chambers are commonly used in mushroom cultivation to create a controlled and suitable environment for different mushroom species.

Here's a basic guide on how to build a simple mushroom fruiting chamber:

Materials you will need:

  1. Plastic storage container with a lid: The size of the container depends on the scale of your mushroom cultivation.
  2. Perlite or vermiculite: These materials help maintain humidity in the chamber.
  3. Hygrometer: A tool to measure and monitor humidity levels.

  4. Temperature and humidity controller (optional but recommended): This helps maintain stable environmental conditions.
  5. Light source: Mushrooms often require light for proper development, so you may need to provide some indirect light
  6. Fan (optional): A fan can aid in air circulation and help prevent the buildup of carbon dioxide.

Steps to build a mushroom fruiting chamber:

  1. Drill Holes: Use a drill to make several small holes in the sides of the plastic container to allow for air exchange. You can also add a few larger holes and cover them with breathable filter material to maintain cleanliness.
  2. Add Perlite or Vermiculite: Place a layer of moistened perlite or vermiculite at the bottom of the container. This layer will help create a humid microenvironment within the chamber.
  3. Place Hygrometer: Put a hygrometer inside the chamber so that you can easily monitor the humidity levels through the side holes.
  4. Install Temperature and Humidity Controller (optional): If you have a temperature and humidity controller, set it up according to the specific requirements of the mushroom species you are cultivating. This will help maintain the desired environmental conditions.
  5. Provide Light: Some mushroom species require light for pinning (the initial stage of fruiting). You can use natural indirect light or install a light source inside the chamber if needed.
  6. Consider Air Exchange: Periodically open the lid or use a fan to exchange air, especially if your chamber is airtight. Mushrooms need fresh air to grow properly.
  7. Monitor and Adjust: Regularly monitor the temperature and humidity levels in the chamber and make adjustments as necessary to ensure the optimal conditions for your specific mushroom species.

Remember that the requirements for mushroom fruiting can vary depending on the species you're growing, so it's essential to research and tailor your fruiting chamber setup accordingly.


We have an assortment of All-In-One Mushroom Grow Bags aka "Fun Bags' for your growing pleasure. Fun bags are literally a window into how mother nature produces mushrooms right inside the bag. 

Our fun bags are a great family or school project. Teach kids how to grow their own mushrooms and they will never go hungry. No yard needed. Grow right indoors from beginning until harvest. Bags can also be grown outdoors. 

These bags to not contain spores or liquid culture. Inoculate with your favorite mushroom spores or liquid culture. 

If you have any questions or need advice please contact us.