Oyster mushrooms, which get their unique name because they look very similar to freshly shucked oysters, are some of the most functional mushrooms in the world. They are mainly found under the ideal conditions of rain and moderate temperatures and tend to grow on decaying hardwood or conifer trees. They stack themselves in layers and clusters to maximize their space and availability.
Traditionally fruiting in the spring and fall, oyster mushrooms are easy to grow and require very little maintenance, making them one of the most cultivated edible mushrooms on the planet, following button mushrooms and shiitake mushrooms. While commercial cultivation of oyster mushrooms is relatively new (only about 100 years old), it’s quickly becoming the norm for the harvesting and distribution of oyster mushrooms commercially worldwide, with China currently producing 85% of the world’s oyster mushrooms.
Oyster mushrooms have deep historical roots in both cuisine and medicinal uses. It’s believed that they also help to break down toxic chemicals in the environment naturally. That’s a fun fact worth exploring!
Fun Facts About Oyster Mushrooms
The oyster mushroom is a saprotroph, which means it feeds on dead or decaying organic material (usually wood).
The caps of the oyster mushroom can range in size from 5 to 25 centimeters (or 2-10 inches) in diameter and are shaped like an oyster or a fan. When the mushroom is young, it will have more of a rolled convex shape. As it matures, this will flatten and turn up. Oyster mushrooms can be many different colors, including white, yellow, brown, and pink!
The mycelia (which is the intricate system of compound cells that make a vegetable, a vegetable) of the oyster mushroom kill and eat nematodes (which are small roundworms) and other bacteria. This makes them one of the very few carnivorous mushrooms.
Oyster mushrooms are also involved in mycorestoration, which is the process of using mushrooms to reduce pollution levels in a specific area. The oyster mycelium will eat through wood, paper, coffee grounds, and at times, even some petroleum products.
Oyster mushrooms can do this due to the enzymes that are released as they grow, breaking down bonds in organic material such as wood into smaller molecules. The carbon-hydrogen bonds found in wood are surprisingly similar to some of the bonds found in oil and pesticides. Oyster mushrooms are miraculously nature’s ultimate recycle factory.
Oyster mushrooms can also absorb and process mercury. They suck the mercury from the ground. After the mushroom is picked and destroyed (do not eat oyster mushrooms that have consumed mercury), the mercury is then successfully removed from that particular environment.
Types of Oyster Mushrooms
Oysters mushrooms vary by type, with three common pleurotus species following the taxonomy: Pleurotus populinus, Pleurotus pulmonarius, and Pleurotus ostreatus. The main difference between the three is primarily the season in which they grow. Otherwise, it’s pretty difficult to tell them apart, until we get into the different colors and sizes.
Here’s a quick guide for popular oyster mushrooms for you fungi enthusiasts out there.
- King oyster (Pleurotus eryngii): The largest of all the oyster mushrooms, king oysters don’t grow individually but in clusters, and have thick, meaty stems and beige caps.
- Pink oyster (Pleurotus salmoneo stramineus): Don’t expect to be eating pink mushrooms (they lose their fabulous hue when cooked) but do expect a chewy texture and pungent taste.
- Pearl oyster (P. ostreatus): If you live in North America and eat oyster mushrooms a lot, this is probably the kind. More mild than shiitake, you’re still getting that notorious woodsy taste.
- Blue oyster (Pleurotus ostreatus var. columbinus): As tasty as pearl oysters, blue oyster mushrooms are less blue and more grey-blue, prettily topped with dark caps and pale gills.
- Golden oyster (Pleurotus citrinopileatus): Bust out of your comfort zone with these bright yellow, aromatic golden oyster mushrooms. Goldens work great as sautéed oyster mushrooms or even crispy fried oyster mushrooms.
Health Benefits of Oyster Mushrooms
Some of the same environmental benefits that oyster mushrooms provide can be utilized in humans. Most notably, oyster mushrooms have shown benefit for reducing inflammation, lowering cholesterol levels, and helping to prevent cancer.
- Cholesterol reduction: An article featured in Mycobiology notes that oyster mushrooms produce compounds known as statins. Statins reduce “bad cholesterol” (LDL) by stimulating receptors to process and clear LDL cholesterol from the body.
- Anti-cancer effects: The anti-tumor effectiveness of oyster mushrooms has also been researched. In a study published in Bioresearch Technology, scientists discovered that polysaccharides similar to those found in oyster mushrooms are believed to stimulate the immune system to fight cancer in laboratory animals.
- Vitamin D rich: Wild mushrooms are also a natural food source of vitamin D. One cup of oyster mushrooms contains about 4% of the recommended daily requirement for vitamin D. The cap provides the most nutrients.
- Heart helper: Mushrooms, including the oyster mushroom, contain a powerful antioxidant called ergothioneine, which has been shown to reduce instances of cardiovascular disease by helping to prevent dangerous plaque from building up in the arteries.
- Nutrient dense: Oyster mushrooms, like many other mushrooms, are also rich in protein, dietary fiber, potassium, vitamin B6, and folate.
The Delicious Edible Oyster Mushroom
Oyster mushrooms have a subtle nutty flavor that complements many soups, stews, stir-fries, and sauces. They are typically available at your local grocery store, although it’s also possible to grow your own or to forage for them in the woods. (However, it is not recommended to pick wild mushrooms. Many dangerous lookalikes can throw off a novice mushroom harvester. Please consult with at least two field guides and someone who is familiar with picking wild mushrooms before consuming any mushrooms that you find in the wild.)
Wild oyster mushrooms smell sweetly like licorice or anise. Cultivated oyster mushrooms have a slightly more seafood-like aroma and taste.
Cooking with Oyster Mushrooms
Some people have a sensitivity to oyster mushrooms. In fact, it’s believed about 10% of the population may have an allergic reaction of some kind to eating any fungus. If you are new to oyster mushrooms, introduce them slowly and over time.
Oysters (even those purchased at a grocery store) can be home to beetles and other bugs, so clean them thoroughly before cooking. The stem and other tougher parts of the oyster mushroom aren’t as edible and are a bit chewy (although they can be eaten). You can use them in a vegetable stock and they will add a sweet, rich flavor.
Oyster mushrooms cook quickly, so if your recipe requires oyster mushrooms, cook them last if possible. While oyster mushrooms indeed complement many dishes, they are most commonly sautéed or stir-fried in olive oil with herbs or spices or soy sauce. Toss them with some freshly minced garlic cloves or butter as another option.