Grain Spawn

Grain Spawn is mushroom mycelium grown into certified organic rye or millet grain which is ideal for inoculating sterilized or pasteurized substrates. Grain spawn is also the industry standard for high volume commercial production. We recommend using grain spawn within one to two months of purchase. Most species must be stored refrigerated, with the exception of Pink Oyster, which should NEVER be refrigerated (and should be used within two weeks of receiving).

Grain spawn is used to cultivate mushrooms in substrates, most frequently in an indoor setting. Please note that we do not provide instruction sheets for making mushrooms blocks as each individual grower has different equipment and different mixes. Before purchasing grain spawn, please read our Spawn Use & Terms Policy.

Grain spawn is used for Oyster, Lion's Mane, Chestnut, Shiitake, Pioppini, Reishi, and Maitake mushroom cultivation.

The more you order, the more you save (mix or match): the volume discount pricing below applies to large bags (4 lb.) of any grain spawn variety:

1 bag: $24.00 ea.
2 - 4 bags: $21.00 ea.
5 - 9 bags: $18.00 ea.
10 - 14 bags: $15.00 ea.
15 - 19 bags: $12.00 ea.
20+ bags: $10.50 ea.