Grain Spawn Bag (3lb) - Mushroom Grain Bag - Sterile

3lb Sterilized Milo Grain Spawn Bag – Injection Port Included

Get started with mushroom cultivation using our sterilized Milo grain spawn bag. Designed for consistency and reliability, each bag provides a clean, nutrient-rich medium for mycelium to colonize. All you need is a spore syringe or liquid culture to begin.

Each bag features:

• 3 lbs of premium Milo (sorghum) grain, carefully hydrated and sterilized

• Self-healing injection port for simple and contamination-free inoculation

• 0.2 micron filter patch to allow gas exchange while keeping the substrate protected

Why Milo for Mushroom Spawn Bags?

Milo, also known as sorghum, is a small, hardy grain commonly used in animal feed and human foods. It’s a favorite in mushroom cultivation for its uniform size, nutrient-rich composition, and reliable moisture retention, making it an excellent medium for mycelial growth.

Lower contamination risk

Milo grains naturally contain fewer endospores and surface microbes than wheat or rye, making them less prone to contamination during colonization. This gives your mycelium a cleaner environment to grow and reduces the likelihood of failed bags.

Efficient colonization

The small, uniform size of Milo grains allows mycelium to access more points per bag, leading to faster and more even colonization. Each grain acts as a miniature hub for growth, so your spawn establishes itself more quickly and consistently than larger, irregular grains.

Nutrient-dense medium

Milo is rich in carbohydrates and essential nutrients, providing steady fuel for healthy mycelial expansion. This nutrient profile helps develop strong, resilient mycelium that can support vigorous growth when transferred to substrate.

Moisture retention and texture

Milo grains hold moisture effectively without becoming soggy, helping maintain the right balance for colonization. Their firm texture prevents clumping, allowing for easy mixing and uniform distribution of mycelium throughout the bag.

Versatile and reliable

Milo works well with spores, liquid cultures, or grain-to-grain transfers, making it a flexible choice for a variety of mushroom cultivation projects. Its consistent performance makes it a favorite among both beginners and experienced growers.

Sterilization Process

Our grain spawn bags are sterilized under controlled high-pressure conditions to provide a reliable starting point for mushroom cultivation. Each bag is sealed in professional-grade bags with a filter patch to maintain sterility until use.

Tips for Colonization

• Inoculate in a clean environment, using gloves to minimize contamination

• Store the grain bag in a stable, shaded area between 55–75°F

• Once the mycelium begins to spread, gently mix inside the sealed bag to encourage uniform colonization

• Full colonization typically occurs in 2–4 weeks, depending on species and culture vigor

Frequently Asked Questions

Do I need special tools to use this bag?

A spore syringe or liquid culture is all that’s required to start. Gloves and a clean workspace are recommended to reduce contamination, but no specialized equipment is needed.

How should I store the grain spawn bag?

Store at room temperature, away from direct sunlight. Refrigeration is not required. When stored properly, the bag can remain viable for several months before use.

What makes Milo better for grain spawn?

Milo is a nutritious, small-sized grain that spreads mycelium quickly and resists clumping, making it ideal for mushroom inoculation bags.

Can I grow mushrooms directly in this spawn bag?

Yes, you can fruit mushrooms directly in the bag, but these mushroom grain spawn bags are designed for expanding into bulk substrate. Fruiting inside the bag works, but mixing your colonized grain into a bulk substrate usually produces larger harvests.

How much spore syringe do I use for a 3lb grain spawn bag?

We recommend 3-5 cc of spore solution or liquid culture for best results. Too little slows colonization, while too much risks excess moisture.

Are these sterile mushroom grow bags reusable?

No. Once used, sterilized grain bags should not be reused. For consistent results, always start with a fresh sterile grain bag.

Do these spawn bags work with liquid culture as well as spores?

Yes. Our injection port bags are compatible with both spore syringes and liquid cultures.

Is this product legal to use?

Yes. These Milo grain spawn bags are intended for lawful mushroom cultivation. They are not designed for illegal mushroom species and should only be used in compliance with local laws.

Can I reuse the bag after colonization?

No. Once colonized, the bag should not be reused. For consistent results, always start with a fresh, sterilized grain bag.

Notice

This product is intended for legal mushroom cultivation only. 

• Arrival Times: See item in cart checkout for accurate arrival times.
• Processing Times: Most orders can be processed within 0-2 days. Small orders will be processed same day if ordered before 1pm.
• International Orders: Buyers are responsible for any customs and import taxes that may apply. Seller is not responsible for delays due to customs.

• Returns accepted on equipment & supplies.
• Product must be unopened in original manufacturers packaging.
• Returns accepted for 7 days.
• Customer provides return shipping.
• No restocking fees to buyer.
• Final sale items: Perishable products (grain, substrate, all in ones, agar, liquid culture, cultures) are not returnable.

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