NORTH SPORE Organic Shiitake Mushroom Grain Spawn

Out of stock
Regular price $30.00

NORTH SPORE Organic Shiitake

Mushroom Grain Spawn

Our USDA-certified organic Shiitake (Lentinula edodes) grain spawn features a popular strain that produces light brown, medium-to-large, umbrella-shaped caps. Shiitake mushrooms are a delicious edible fungus from East Asia and their flavor is described as rich, savory, buttery, and umami.

This strain tends to produce generous flushes, making them a great mushroom for confident beginners. They colonize quickly and are the most reliable producers of any species, which is why they are ideal for commercial cultivation.

Skill level


Grow location


Spawn shelf life

4 months (refrigerated)


USDA certified organic

Bag weight

6 lbs

Fruiting temps


Recommended use:

Shiitake grain spawn can be used for indoor production using sawdust or straw. 

Do not use grain spawn for log inoculation.

This is not a mushroom grow kit. Shiitake grain spawn must be combined with a substrate in order to fruit. 

Upon receiving your spawn:

Remove it from the shipping box as soon as possible. Then, unfold the top of the bag, making room for air space. It's also important to check and confirm that the filter patch is not obstructed. This will help the organism breathe and continue to thrive!


  • Weight: Approximately 6 lbs
  • Hydration: Average of 47%
  • Bags: Gusseted 2.2 mil polypropylene
  • Filter: High efficiency .2 micron
  • Inoculation Rates: 6 lb. bag of grain will inoculate between 120-165 lb. sterilized sawdust, and 100-130 lb. pasteurized straw
  • Sterilization method: Commercial grade autoclave sterilized

Temp, Humidity & CO2 guide:


55-70°F  |  13-21°C

Humidity (Phase 1: Primordia)


Humidity (Phase 2: Fruitbody)


CO2 Sensitivity (Phase 1: Primordia)

500-700 ppm

CO2 Sensitivity (Phase 2: Fruitbody)

<1,000 ppm

  • Primordia -  The earliest recognizable stage of fruitbody development. Also known as “baby mushrooms” or “mushroom pins.”
  • Fruitbody - A fully grown mushroom, the reproductive structure of the organism in which the spores are produced.
  • CO2 sensitivity - When CO2 levels are too high, yields will decrease, stems will become long and stringy, caps will be small, and/or growth will halt.

Indoor cultivation:

Shiitake mushroom grain spawn can be mixed into sterilized hardwood sawdust to create shiitake substrate blocks.

Note: Grain spawn must be mixed with bulk substrate before you can fruit it. If you are new to growing mushrooms, we recommend purchasing a book on mushroom cultivation.


If you don't plan to use immediately, you can refrigerate your spawn for up to 4 months.


Shiitake has a meaty texture when cooked and is good for drying and reconstituting in winter soups. It pairs beautifully with tamari, ginger, and garlic and can bring needed umami to many different dishes. These mushrooms are delicious sauteed and can be used in stir-fries, risottos, ramens, on pizzas, or simply eaten by themselves.


Our grain spawn is USDA certified organic and made using organic cultures from our own culture bank. It contains a blend of locally sourced, organic, and non-GMO ingredients from farms in New England and North America.

Cautions & Considerations:

If you’re going to consume home-grown mushrooms, make sure to cook your fresh mushrooms thoroughly with heat. If it is your first time eating this species, it is best to start with a small amount to check for allergies, even if cooked.

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