A mushroom spawn grow bag is a specialised polypropylene (PP) bag designed for sterile mushroom cultivation.

Key features explained:

• High temperature resistant → safe for pressure cookers/autoclaves (~121–125°C)
• Filter patch (usually 0.2–0.5 micron) → lets air in but blocks contaminants
• Pre-sealable → you heat seal after inoculation to keep it sterile
• Gusseted bottom → stands upright and holds substrate
• Material (polypropylene) → won’t melt under normal sterilisation temps