Once upon a time, in the late 20th century, the only mushroom you could find in a U.S. supermarket was the diminutive button mushroom. After that, portobellos arrived in both macro and microform, and then shiitakes crept in. But by the time the 2000s came around, there was a clear shift: The gourmet mushroom-growing business began to boom as technology to cultivate them evolved and demand grew. Fresh oyster mushrooms (species of Pleurotus), previously a wild-only edible fungus, are now within a curious cook’s reach. They are delicious, nutritious, and readily available at major grocery chains as well as at farmers’ markets. Their smooth clusters look unusual, and their texture is unfamiliar. How are oyster mushrooms cultivated, and what is the best way to use them? What parts of them do you eat, and do they have any health benefits? All good questions, with fascinating answers. Oyster mushrooms are magical (but…not in that way).

In the Wild

In the wild, oyster mushrooms grow in overlapping shelves on logs or living trees. They are saprotrophic, digesting organic matter, and they cause a white rot that kills hardwood trees (which they infect through a wound in the bark). Their stems are often lateral (growing to the side) and are short and stout. White gills extend partially down those stems. They are impervious to seasonal shifts and you may find them on a muggy summer afternoon or in the middle of winter, as long as there has been some rain.

Cultivated Oyster Mushroom

Once cultivated only in East Asia (China still exports more oysters mushrooms than any other country), American production increased earlier this century as interest in oysters grew. Commercially-produced oyster mushrooms are grown from mycelium (interwoven, threadlike matter) that is propagated on a base of cereal grain. This mixture is called spawn and is used to inoculate the substrate (the organic material that the mushrooms feed on). Read more: https://bit.ly/3IiYOBT