The Workhorse of Commercial Spawn Production

Step up your production with the SPeS Large Gusseted Spawn Bag. Measuring 13 x 12 x 50cm, this bag is the industry standard for growers moving beyond jars into bulk colonization. It is specifically sized to accommodate 2kg of hydrated grain, ensuring enough headspace for effective shaking and rapid mycelial expansion.

Ideal For:

• Bulk Grain Spawn: Optimized for 2kg batches of rye, wheat, or sorghum.

• Commercial Expansion: Perfect for Generation 2 (G2) and Generation 3 (G3) transfers.

• Large-Scale Inoculation: The high volume makes it easy to inoculate multiple fruiting blocks from a single bag.

Technical Specifications & Features:

• Bacterial-Grade 0.2μm Filter: The high-precision ePTFE patch filters out 99.9% of competitors, including bacteria and mould spores, while allowing the high levels of gas exchange required for bulk grain volumes.

• Industrial Strength (60 Micron): Made from premium, heavy-duty Polypropylene (#5). This thickness is chosen to prevent “pin-holing” during the aggressive shaking required to break up 2kg of colonized grain.

• Autoclavable Reliability: Engineered to withstand sterilization cycles up to 126°C (260°F) without clouding or becoming brittle.

• Pliable & User-Friendly: Our unique production process ensures the bags remain soft and flexible post-sterilization, making them easy to handle in front of a flow hood.

• Gusseted for Stability: The side-gusseted design allows the bag to stand firmly upright. This makes it easier to fill without assistance and maximizes the space inside your pressure cooker or autoclave.

• Hydrophobic Filter Patch: The filter repels moisture, ensuring that steam or condensation does not block the “breathing” pores of the bag during the colonization run.

• Industrial Bottom Seal: Manufactured with a reinforced 4mm wide bottom heat seal. Specifically engineered for high-pressure environments and load-tested to 10kg to prevent blowouts during handling and sterilization.

How to Use Your Gusseted Spawn Bag

A bag is a bag… until you fold it right! To avoid blow-outs, maintain perfect sterility, optimal moisture, and get the best colonization results, check out our detailed step-by-step tutorial:

👉 Sterilizing Commercial Grain Spawn Bags – Full Tutorial

It covers proper folding technique, filter orientation, loading tips, sterilization cycles, and common pitfalls to avoid.

Why Choose the 13 x 12 x 50cm Size?

• Efficiency: One bag holds roughly 6x the volume of a standard spawn jar, drastically reducing your lab labour.

• Ergonomics: At 2kg of grain, the bag remains easy to “break and shake,” promoting faster 100% colonization compared to overstuffed smaller bags.

• Space Saving: The square-bottom footprint allows for tight “brick” packing during incubation, saving valuable shelf space.

Invest in the scale of your operation. The STS-Tested Large Spawn Bag provides the volume and sterile security required for professional-grade results every time.