Using Rye Berries for Mushroom Spawn

Using rye berries for grain spawn is a common and effective method in mushroom cultivation, especially for species like Psilocybe cubensis. Rye berries are a popular choice due to their nutrient content, which supports healthy mycelial growth. Here's how you can use rye berries for grain spawn:

1. Select and Prepare Rye Berries:

  • Choose whole, untreated rye berries. Make sure they are clean and free from contaminants.
  • Rinse the rye berries thoroughly under running water to remove any dust or debris.
  • Soak the rye berries in water for about 12-24 hours, or until they have absorbed enough moisture to swell up. Drain the excess water.

2. Load Jars with Rye Berries:

  • Sterilize the jars you plan to use. You can do this using a pressure cooker or an autoclave.
  • Fill each jar with the soaked and drained rye berries, leaving some headspace at the top of the jar.
  • Optionally, you can add a small amount of gypsum (calcium sulfate) to improve the texture and moisture retention of the grain.

3. Sterilize the Jars:

  • Seal the jars with a breathable material, such as a layer of polyfill or a filter disc, to allow for gas exchange but prevent contaminants from entering.
  • Sterilize the jars in a pressure cooker or autoclave at 15 PSI for at least 60-90 minutes. This step is crucial to kill off any potential contaminants.

4. Inoculate the Jars:

  • Allow the sterilized jars to cool down to room temperature in a clean and draft-free area.
  • Inoculate the jars with mushroom spores or liquid culture by injecting a small amount of the inoculum through the breathable filter. Use a still air box or a laminar flow hood to maintain sterile conditions.

5. Incubation:

  • Place the inoculated jars in a dark, warm (around 75-80°F or 24-27°C) incubation chamber. Mycelium will begin to grow and colonize the rye berries over the next few weeks. It may take anywhere from 2-4 weeks for the mycelium to fully colonize the grain.

6. Shake or Agitate the Jars:

  • To speed up colonization and ensure an even distribution of mycelium, gently shake or agitate the jars when the mycelium growth is about 30-40%.

7. Colonization Completion:

  • Once the mycelium has fully colonized the rye berries, it's ready for use as grain spawn. You'll see a white, fluffy mycelial mass covering the entire contents of the jar.

8. Use the Grain Spawn:

  • You can use the fully colonized rye berry jars to inoculate your fruiting substrate, such as a bulk substrate or individual fruiting containers.

Remember to maintain good hygiene practices, work in a clean and sterile environment, and follow a reliable mushroom cultivation protocol to maximize your chances of success. Properly prepared and sterilized rye berry grain spawn will provide a strong and healthy mycelium network for your mushroom cultivation project.


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.