How to Spawn to Bulk for Beginners


Introduction: ‘Spawning to bulk’ is the process of transferring your colonized grain (spawn) to a larger substrate to initiate the fruiting stage of mushroom growth. This guide is tailored for beginners, providing detailed steps to ensure a successful transition.

Materials Needed:

  1. Fully colonized grain spawn.
  2. Bulk substrate (e.g., coco coir, vermiculite, gypsum mix).
  3. Large mixing container.
  4. Sterile gloves.
  5. Alcohol wipes.
  6. Large tub or monotub for fruiting.
  7. Spray bottle with water.
  8. A clean, still-air environment.

Steps:

  1. Preparation:
    • Clean and disinfect your workspace.
    • Wash your hands thoroughly and put on sterile gloves.
    • Ensure your bulk substrate is prepared and pasteurized as needed.
  2. Hydrating the Substrate:
    • Make sure your bulk substrate is at field capacity, meaning it’s moist but not dripping water.
  3. Layering Spawn and Substrate:
    • In your large tub, create a layer of the bulk substrate about 2 inches deep.
    • Break up your colonized grain spawn and sprinkle a layer over the substrate.
    • Repeat these layers, ending with a layer of the substrate on top.
  4. Mixing (Optional):
    • Some growers prefer to mix the spawn and substrate together for more even colonization. If you choose to mix, do so gently to avoid damaging the mycelium.
  5. Incubation:
    • Cover the tub with its lid. If it’s a monotub, make sure the air exchange holes are covered with micropore tape.
    • Place the tub in a warm, dark place (around 75°F).
    • Check daily for moisture levels, ensuring the substrate doesn’t dry out.
  6. Monitoring Colonization:
    • After a few days, you should see mycelium starting to colonize the bulk substrate. This process can take 1-2 weeks.
    • Once fully colonized, the surface will be covered in a white, web-like mycelium.
  7. Initiating Fruiting:
    • Once fully colonized, move the tub to a place with indirect natural light.
    • Adjust the temperature to around 70°F.
    • Begin misting the surface with water and fanning for fresh air exchange several times a day.

Conclusion: Spawning to bulk is a crucial step in mushroom cultivation that requires patience and care. By following these steps, beginners can successfully transition their colonized grain to a bulk substrate, paving the way for mushroom fruiting. Remember, cleanliness and monitoring environmental conditions are key for a successful spawn to bulk process.