North Spore Organic Sterilized Grain Bag with Injection Port for Mushroom Cultivation (3 lb)

This best-selling organic sterilized grain spawn bag was formulated by mycologists to maximize the speed and size of your mushroom grow. Each spawn bag contains our proprietary blend featuring hydrated, nutrient-rich, organic millet and wheat berries. Bags also include a self-healing injection port for use with a spore or culture syringe plus a 0.2 micron filter patch to block airborne contaminants while providing even gas exchange. Note: Color of injection port may vary.

Spawn to bulk ratio

We recommended 1 lb of colonized grain spawn for every 5 lbs of manure or hardwood sterile substrate. We also recommend using 2.5-5ccs per 3 lb injection port bag. (See Inoculation and Colonization below for full details.)

Why millet?

Millet has a much lower endospore load than rye and wheat, making it less prone to contamination. And its small size means your spawn will have many more inoculation points for the same volume of grain. By using millet, the mycelium will spread more evenly and abundantly through the substrate. And, as a high-nutrient medium, it also encourages rapid mycelial expansion.

Sterilization

North Spore grain spawn bags are sterilized in a commercial-grade autoclave. Sterility is verified using biological indicators and temperature sensors.

Inoculation

To inoculate the grain bag, simply inject your spore or culture syringe through the port in a sterile location. We always recommend clean hands and latex gloves to reduce the introduction of contaminants.

It is best practice to wait a minimum of 1 week after arrival before injecting grain bags to ensure they were not compromised during transit. Rest assured that your purchase is 100% guaranteed. If your bag was compromised, we will replace it. 

We recommend using 2.5-5ccs per 3lb injection port bag. We do not typically recommend using an entire syringe in one bag. Doing so adds excessive moisture which can create over saturation in the bag. This over-saturation can pool and is prone to being anaerobic and the mycelium will have a hard time colonizing.

Colonization

Allow your bag to colonize in a cool location out of direct sunlight. Temperature for incubation shouldn't exceed 75 degrees F or dip below 55 degrees F. After a couple weeks, you should start to see mycelium growing on the grain. 

You'll notice the white mycelium growing outward from the injection point. When it has grown three to four inches you should, without opening the bag, carefully break up the colonized grain and mix it into the uncolonized grain. This will dramatically speed up the colonization process.

When the bag is completely white with mycelium your spawn is ready to use. This may take a couple weeks to a month or more depending on the species and vigor of your culture.

Storing Grain Bags

Grain bags should be stored at room temperature out of direct sunlight. No refrigeration is necessary. They can also be stored for several months before use.