Collection: Buy Mushroom Grain Spawn

Fungi Ally Mushroom Grain Spawn

is great to use for indoor inoculations including straw, coffee grounds, and supplemented sawdust. The small particle size of millet allows for fast growth onto the inoculated substrate, making it even easier to grow your own tasty mushrooms. Our mushroom grain spawn is second generation so you can further expand the mycelium several times. All Fungi Ally spawn is grown in a sterile lab and produced year-round to ensure you get fresh pure mushroom mycelium of the highest quality. We have grain spawn strains available for growing shiitake mushrooms, blue oyster mushrooms, yellow oyster mushrooms, pink oyster, lion’s mane mushrooms, maitake, reishi, and chestnut mushrooms. *Please note that shipping may take around 2-3 weeks due to high order volume.

Interested in bulk mushroom grow kits? For custom orders of other species or large quantities email

To inoculate coffee grounds with oyster mushroom grain spawn:

Coffee grounds are a great substrate to use to grow oyster mushrooms. Most people brew coffee daily and just by adding sawdust and mushroom spawn you can grow some beautiful oyster mushrooms! 

  1. Start with a small plastic container like a yogurt container, 1 gallon bucket, or food take out container. You will also need oyster mushroom grain spawn and FRESH HARDWOOD sawdust. It is important that the sawdust is both fresh and hardwood. 
  2. Brew your morning cup of coffee or pot of coffee. Place a handful of sawdust at the bottom of the container and a handful of spawn on top of that.
  3. After allowing the coffee to drip dry add the filter and grounds to the container, cover with another handful of spawn and finally a handful of sawdust, replace the top of the container.
  4. Roll the mushroom spawn bag tight and place in the fridge until the next use. 
  5. Repeat these steps whenever you brew a cup until the container is full. 
  6. Once the container is full allow it to sit for 2 weeks, when you open it you should see white fluffy mycelium that smells sweet. 
  7. After 2 weeks, poke 4 holes in the sides of the container for the mushrooms to fruit out of. Mist the outside of the container 2X daily to encourage the mushrooms to fruit 
  8. Harvest and enjoy your mushrooms! The container should fruit multiple times. 

If you gather coffee grounds from a coffee shop or have a lot at once you can freeze them until you inoculate or inoculate an entire 5 gallon bucket using the same steps as above all at once. It is best to use grounds the same day they are brewed to decrease contamination. The sawdust helps to increase aeration and keep the container from going anaerobic. 

Toilet Paper inoculation:

Growing Oyster or chestnut mushrooms on straw: 

Oyster mushroom cultivation on straw can be broken into four parts, treatment of the straw, inoculation, incubation, and fruiting. Each step is crucial to the next and affects the overall yield. The step-by-step process of growing oyster mushrooms on straw is outlined below. 

1) CHOP STRAW By chopping the straw the cell walls of the straw are broken making it easier for the oyster mycelium to access the nutrients in the straw. Chopping the straw makes the particle size smaller allowing a more compact substrate. A relatively small gap of 1-2 inches between pieces of straw is like the Grand Canyon for mycelium to grow over. It takes wasted energy and time for the mycelium to try and grow over these sorts of gaps. By chopping the straw and firmly packing the bags air pockets can be minimized and yield increased. 

2) TREAT STRAW Using the method which best meets the needs of the grower the straw is prepared for the oyster mycelium. By treating the straw microorganisms are killed and competition for the available nutrients is limited. The two best ways we have found to treat straw is by pasteurization, heating the straw to 145 degrees for 2 hours or our favorite the Lime Technique: With this technique use hi-yield brand of hydrated lime to raise the pH to 13, about 1 cup lime per 5 gallon bucket of straw and water. Place the straw in the bucket and add lime and water until the straw is fully submerged. Allow the straw to soak for 16 hours. Pull the straw out allowing it to drip dry and then inoculate. 

 3) INOCULATE Add spawn into the treated straw. This is the material used to introduce the mushroom mycelium to the new substrate. This can be done in buckets or bags, place holes at the bottom to allow any excess water to drain out. 

4) INCUBATE Incubation should ideally occur at 75 degrees for about 3 weeks depending on the inoculation rate. Bags should be placed with at least a palm distance between them to limit overheating. 

5) FRUIT There are 4 parameters to be aware of when fruiting. They are light, humidity, temperature, and CO2 level. For most oyster mushrooms a well-lit room at 85-90% humidity, 65 degrees, and CO2 below 800 PPM is ideal. 

6) HARVEST Harvesting typically occurs about 5-10 days after the substrate is moved into fruiting conditions. Mushrooms should be harvested before the caps completely flatten out.