When growing mushrooms, the mycelium first needs to be grown on a sterilized grain substrate, like rice, oats, or rye. You can think of mycelium as the “root structure” of the mushrooms and myceliated grain like the “seeds” in the mushroom growing process.
To grow whole fruiting body mushrooms, this myceliated grain (also known as grain spawn) needs to be added to another substrate like hardwood sawdust or logs. Only then can full mushrooms be grown.
You can tell products that use myceliated grain because they will have something like “myceliated rice” or “mycelium biomass powder” on the ingredient list. In our opinion, these products should be avoided if you want to get the benefits from mushrooms.