THE INCREDIBLE OYSTER MUSHROOM: A COMPLETE GUIDE

The ubiquitous Oyster mushroom is one of the most common edible mushrooms in the world. There’s 202 known species in the family, all of which are edible. They’re easy to grow, fairly easy to identify, and versatile to cook with.

Oyster mushrooms work to decompose wood rather than feed off of it, which means they return vital elements and nutrients to the ecosystem in a form that other plants can use. Because of their ability to digest whatever surface they grow on, they show great promise for bioremediation – the use of living organisms to remove pollutants from the environment. They’ve successfully cleaned up oil spills in the Amazon and treated contaminated soil in New Zealand.

They’re one of only a few carnivorous mushrooms in existence. The mycelia of Oyster mushrooms release a chemical that attracts nematodes, then paralyzes them with a sticky toxin. By consuming these worms, they’re able to get a boost of nitrogen.

Habitat and identification

Where can you find Oyster mushrooms?

Oyster mushrooms grow on and near trees in subtropical and temperate forests of the world. As wood decomposers, they often grow on logs and dead standing trees. They tend to prefer deciduous trees, especially oak and beech. Open, leafy forests make them happy and they tend to grow in the shade.

How to identify Oyster mushrooms in the wild

Whenever you’re foraging for mushrooms, make sure you’re completely certain about your identification before you consume any. Better to be safe than sorry!

wild oyster mushroom growing on a tree
Image from ForageSF

 

Although they can be identified fairly easily, Oysters do have some toxic look-alikes – most notably the Western Jack o’Lantern (which is bioluminescent!) and the Ivory Funnel. Get to know the differences between these mushrooms before you go out foraging.

Oyster mushrooms are typically a light gray or grayish-brown color in the wild, although they’re now cultivated in many colors. Their spore sprint is white to lilac-gray and best if viewed on a dark background.

These mushrooms tend to grow in clusters or shelf-like formations, with broad, oyster- or fan-shaped caps that are two to ten inches across. Fresh oyster mushrooms should have firm white flesh and white gills. Their gills are decurrent, which means they attach to the stem and run most of the way down it. Most varieties have little to no stipe. 

Luckily for mycophiles, Oysters grow for a long season, spring through fall. They tend to thrive off significant changes in weather, like after the first frost.

Types of Oyster mushrooms

There’s a wide range of Oyster mushrooms, both wild and cultivated. They grow in a variety of gorgeous colors with subtly different flavor profiles. 

varieties of oyster mushrooms
From top left: Golden, King, Blue, and Pink Oyster mushrooms
Wild species include:
  • Pearl Oyster (Pleurotus ostreatus). The most common variety, especially in North America, it’s also widely cultivated.
  • Phoenix Oyster (Pleurotus eryngii). Tends to have smaller, paler caps and a bit longer stem. Grows in late summer as it prefers a bit more heat than other varieties.
  • King Oyster (Pleurotus eryngii) As you might guess, it’s the largest of the Oyster species. With meaty white stems and chestnut-colored caps, they look quite different from the other varieties.
Cultivated varieties include:
  • Blue Oyster (Pleurotus ostreatus var columbinus). Bluish-gray caps with white gills, a striking contrast.
  • Golden Oyster (Pleurotus citrinopileatus). Bright yellow from stipe to caps. Said to have a slightly more complex flavor.
  • Pink Oyster (Pleurotus salmoneo stramineus). Impressively bright pink in color with a slightly ruffled appearance.

Growing and harvesting Oyster mushrooms

P. ostreatus was first grown in Germany for subsistence during the first World War. They’re now widely grown throughout the world for food as well as bioremediation.

Oysters are one of the easiest mushrooms and to grow. They’re not picky about the substrate they’re grown in and can tolerate a variety of growing conditions. They’ll thrive in a warm, humid environment.

With a mushroom growing kit and a spray bottle of dechlorinated water, you can grow Oyster mushrooms in just a couple weeks. Set up a “humidity tent” by placing an aerated tub or plastic bag over the grow kit and remove a few times a day to mist the mushroom block with water.

fresh organic oyster mushrooms grown in bellingham washington

When they’re ready to harvest, they should have a springy texture and bright color. You’ll know they’re ready when the clusters of mushrooms get large and the edges begin to flatten out. To harvest them, you can simply grasp them at the base where they emerge from the bag and gently twist and pull to remove the entire cluster. Pull away any mushroom bits that remain on the kit, and a second flush will form at the same holes.

You can store Oyster mushrooms in the fridge in a paper or plastic bag for about a week.

Health, Nutrition, & Benefits

Nutrition

Oyster mushrooms are a great addition to a healthy diet. They contain about five grams of protein per serving. They’re high in potassium, magnesium, and folate, plus they contain a decent amount of fiber and other essential vitamins and minerals. You can find about 21% of your daily intake of niacin in these mushrooms, and 18% of your riboflavin needs.

They’re also high in antioxidants, helping the body to eradicate high concentrations of free radicals. 

Medicinal potential

Although they’re not among the more famous mushrooms being studied for their medicinal benefits, Oyster mushrooms show some potential for certain ailments. Human studies are limited, but lab experiments have shown that they contain antifungal and antitumor properties. One study found that Pleurotus ostreatus was the most potent mushroom for suppressing cancer cells.

More studies are being done on the potential for oyster mushrooms to treat diabetes, as they may lower blood sugar and increase insulin levels. In addition, oyster mushrooms contain statins and have shown a significant decrease in cholesterol levels in study participants.

How to cook oyster mushrooms

As a delicate mushroom, Oysters are best cooked in a dry saute. Begin by chopping off the “heart” of the Oyster Mushroom cluster (where all the stems come together) and coarsely chop up the caps and stems. Cook them up in a skillet over medium high heat until all their water releases and simmers off, then add your fat of choice and season with salt and pepper, adding fresh garlic cloves if you desire.

Their texture is smooth and they have a slight seafood flavor, though some people find they have a subtle hint of anise. Overall, the flavor is mild and nutty, which makes them very agreeable in a variety of dishes.

 Fresh Oyster mushrooms are great in pasta, stir fry, soup, egg and fish dishes. They’re also delightful as a side dish on their own. For Oyster mushroom recipes, check out our recipe collection.