3-Grain Mushroom Spawn Bag
3-Grain Mushroom Spawn Bag
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Warranty & Refund Policy
Warranty & Refund Policy
Within the first 30 days of placing your order we guarantee that your substrate product is free from defects or we will replace it and ship the replacement product for free. If the product has been already been used we will issue a store credit only for product purchase price minus a 20% processing fee. Shipping fees and sales tax are non-refundable.
To file a claim please take at least 3 close up photos of the injection port and each bag or jar showing us the issue so we can review your claim. We offer replacement products only on defective or damaged products. No need to return products.
Spawn Bag & Jar Tips
Spawn Bag & Jar Tips
After injecting your bag or jar, give it a gentle shake. For bags, make sure any grains stuck in the upper portion are knocked down so they can colonize properly. There’s no need to break up the spawn during colonization unless you prefer to. If you choose to do so, wait until the bag or jar is roughly 50% colonized before mixing.
User Guide
User Guide
Download our substrate inoculation guide here.
Rewards Program
Rewards Program
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SKU: SKU:3GRAINSB3LB-1
3-Grain Mushroom Substrate Spawn Bag — Sterile, Ready to Inoculate, Chef-Mycologist Crafted
Bring professional mushroom cultivation into your home with our 3-Grain Mushroom Substrate Spawn Bag, a premium sterilized triple-grain grow bag designed for gourmet and medicinal mushroom growers. Each bag blends three carefully balanced grains—organic millet, rye, and wheat—to create a nutrient-rich substrate that promotes rapid colonization and vigorous mycelium growth.
Unlike ordinary single-grain bags, this sterile 3-grain mushroom substrate spawn bag with injection port and filter patch is optimized for superior gas exchange and even moisture distribution. Our unique grain blend provides diverse carbohydrates, proteins, and trace minerals—everything your mushroom culture needs to thrive. Whether you’re inoculating with liquid culture, agar plates, or spore syringes, this bag offers professional-grade performance straight out of the box.
🧑🍳 Crafted by Chef-Mycologist for Perfect Texture & Moisture
As both chefs and mycologists, we approach substrate preparation like fine cuisine. Each grain batch is cooked “to the tooth,” not by timer—ensuring the grains remain firm yet hydrated for maximum mycelium penetration. After sterilization at 15 PSI, every 3-lb 3-grain mushroom substrate spawn bag is vacuum-sealed for freshness and shelf-stability.
Our 3-grain substrate spawn bags for gourmet mushroom cultivation mirror what professional farms use but are sized and priced for home growers. You’ll notice faster colonization, less clumping, and exceptional yield potential in every grow.
🌬️ Premium Design for Clean, Hassle-Free Growing
Each 3-grain mushroom substrate grow bag features a 0.5-micron synthetic filter patch for safe gas exchange and a self-healing injection port for effortless inoculation. Simply sanitize your work area, inject your culture, and let the bag do the rest. The peel-and-seal design maintains sterile conditions while allowing CO₂ release, preventing contamination even during extended incubation.
We hand-inspect each bag for moisture balance and seal integrity before shipping. These sterilized 3-grain mushroom spawn bags made in the USA are trusted by growers who demand consistent, contamination-free results.
🌱 Why Choose a 3-Grain Mix?
A multi-grain substrate offers distinct colonization advantages:
- Millet adds fine texture for dense mycelial growth.
- Rye berries provide strong nutritional density.
- Wheat grain supports moisture retention and structure.
Together, they form a balanced 3-grain substrate for mushrooms that supports diverse species like lion’s mane, oyster, shiitake, and reishi.
✅ Key Features
- Sterile, ready-to-use 3-grain mushroom substrate spawn bag with injection port
- Organic millet, rye, and wheat blend for nutrient diversity
- Vacuum-sealed and sterilized at 15 PSI
- 0.5-micron filter patch for optimal air flow
- Perfect for home or small-batch gourmet mushroom cultivation
- Proudly made in the USA
🛒 Ideal For
- Hobby and professional cultivators
- Gourmet and medicinal mushroom species
- Educational mycology projects
- Shopify Collective stores and resellers
