Pre-Sterilized Mushroom Substrate | 6-Pack

Pre-Sterilized Mushroom Substrate - 6-Pack of Ready-to-Inoculate Blocks

Skip the pressure cooker and start growing mushrooms today. Each 3.5 lb block of pre-sterilized mushroom substrate arrives fully sterilized and ready for inoculation with your favourite mushroom spawn. No equipment, no prep work, no guesswork. This is the fastest way to go from spawn to fruiting mushrooms, whether you are a beginner starting your first grow or an experienced cultivator looking to save time. Made in our CFIA-licensed facility in Brantford, Ontario.

What Is In the Substrate

Our mushroom substrate Canada formula uses a carefully balanced 80/20 ratio of natural hardwood sawdust and organic wheat bran at 60% moisture content. This blend provides the ideal nutrition and structure for vigorous mycelium growth and abundant fruiting across a wide range of gourmet mushroom species. The hardwood sawdust provides the carbon-rich base, while the organic wheat bran supplies the nitrogen supplement that drives aggressive colonization and heavy yields.

Compatible Mushroom Species

• Oyster mushrooms: pearl, blue, pink, king, and other varieties. Expect 1-1.5 lbs per block.
• Lion's mane: up to 2 lbs per block with vigorous genetics.
• Chestnut mushrooms: 1-1.5 lbs per block.
• Shiitake, maitake, reishi: all hardwood-loving species perform well.
• Turkey tail, black poplar, and more: any species that naturally grows on hardwood.

How to Use

Inoculate

Working in clean conditions (a still air box is ideal), open the bag and add your grain spawn or liquid culture. Break up the spawn and mix it thoroughly through the substrate by kneading the outside of the bag.

Seal and incubate

Seal the bag and store in a clean, dark space at 20-24 C. Colonization takes 2-4 weeks depending on spawn ratio and species. The substrate is ready to fruit when fully covered in white mycelium.

Fruit

Cut an X in the side of the bag or remove the block entirely and place in a fruiting chamber. Maintain 80-90% humidity and provide fresh air exchange. Expect your first harvest in 4-6 weeks from inoculation.

Storage

• Best results: inoculate immediately upon arrival
• Room temperature: up to 2 weeks
• Freezer: up to 3 months

Why Choose Pre-Sterilized Substrate

Sterilization is the most technical and time-consuming step in mushroom cultivation. It requires a pressure cooker or autoclave, hours of processing time, and careful technique to avoid contamination. Our pre-sterilized substrate eliminates all of that. Each bag is steam sterilized in our facility using laboratory-grade standards, then sealed in filter patch grow bags for optimal gas exchange during shipping and storage.

For home growers, this means you can start growing mushrooms without investing in expensive sterilization equipment. For experienced cultivators, it means freeing up your autoclave for grain spawn runs while letting us handle the substrate prep. Each 6-pack provides enough substrate for a serious grow or for testing multiple species simultaneously.

Made in Brantford, Ontario. Ships free across Canada. Nature Lion has served over 50,000 Canadian mushroom growers since 2020.