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, organic is best. Make sure they are clean and free from contaminants. If using organic rye berries they have already been triple rinsed post harvest.
• Rinse the rye berries thoroughly under running water to remove any dust or debris. 
• Soak the rye berries in water (3 parts water to 1 part rye berries) for 12–24 hours, or until they’ve absorbed enough moisture to swell. Once soaked, bring them to a boil in a pot and cook until tender to the tooth—typically 10–25 minutes. Keep a close eye on them as they cook; the first sign they’re nearing readiness is when a few grains begin to burst. Aim for the rye to be about 85% cooked. Typically the rye berries will double in size during the boiling process. Drain them well as soon as they are done. 
• Optionally, you can add a small amount of gypsum (calcium sulfate) in the water to improve the texture and moisture retention of the grain. It also buffers the PH.

2. Load Jars with Rye Berries:

• It's best to use quart mason jars and fill each one up with a pound of rye berries, wipe rim of jar with an alcohol wipe.. Place a spawn jar canning lid with an injection port and gas exchange filter and screw on the jar band tightly.
  

3. Sterilize the Jars:

• Sterilize the jars in a pressure cooker at 15-18 PSI for 90 minutes to 2 hours depending on your altitude. 
  

4. Inoculate the Jars:

• Allow the sterilized jars to cool down to room temperature in the pressure cooker. 
• Flame needle until glowing and let cool 5 seconds and then Inoculate the jars with mushroom spores or liquid culture by injecting a small amount of the inoculum 3cc on average through the injection port that has been sanitized prior with isopropyl alcohol. Use a still air box or a laminar flow hood to maintain sterile conditions.
• Flame the needle for a few seconds prior to each injection. Wipe needle first with isopropyl alcohol prior to flaming needle if needed.

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.
• If no incubation chamber it's best to make a small tent over the top of each jar cap with aluminum foil. This will allow air exchange but maintain the needed grain moisture needed to fully colonized.

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. You can also make liquid culture from the colonized grain.

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.

Typically 1 pound of dry rye berries will weight approximately 1.80 pounds once cooked.