I was out for a walk in the woods with my buddies last week when I spied with my mushroom vision some perfect wild white oyster mushrooms growing on some trees. I harvested them gleefully with my knife, put them in a large paper bag, and proudly presented them to Sarah when I returned from my foraging adventure. While she pondered the culinary possibilities and set to work making oyster mushroom tempura, I turned to my tomes of mushroom knowledge and harvested the wild spores for cultivation using two methods: suspending the spores in water to store for later use and taking samples from the less pretty ones to add to sterilized coffee grounds and rye grain. The Mushrooms in the rye grain are already full of the white fuzzy mycelium and it won't be long until they are ready to fruit and sell at the Killaloe Farmers' Market this summer.
Pleurotus ostreatus, also known as the oyster mushroom, is one of the mushroom world’s most versatile, healthy, tasty, and prolific mushrooms. Often fruiting in the cool spring and fall after a bout of rain, oyster mushrooms vary in colour and habitat, always growing on dead wood. The most common oyster colours are pure white, grey, or blue, and they grow wild through much of North America easily withstanding temperatures that approach freezing, often not fruiting at all after temperatures break 30°C. If you are lucky, in North America you can find variants that have escaped which are pink or “pinkish” in colour of an Asian variety (or hybrid) that is frequently cultivated, but requires higher temperatures to fruit and much less tolerance to freezing.
After hearing about escaped oyster mushroom cultivars its hard not to think:
“How did they let that escape?”
Well one of the key characteristics of Oyster mushrooms is their prolific spore production, and when I say prolific I mean: forget a bunch of oyster mushrooms on a table and the next day you will have a table covered in insidious spores.
Then you might think:
“Hey cool spores!”
While this thought is partially correct (mushroom spores ARE cool), we learned from an unpleasant first-hand experience that oyster mushroom spores are well known to cause airway irritation when inhaled, as well as contact dermatitis if large areas of skin are exposed. Which means, because spores are microscopic, they get on your clothes, in the air, under your nails, etc... it can quickly make an environmental nightmare for those who are allergic to mushrooms and moulds, and easily allows for cultivated strains to get loose. Keep them contained in a paper bag in the fridge until you are ready to cook with them or dry them.
Speaking of allergies, it is important to mention that with any mushroom, wild, or farmed, the first time you try it, try only a small amount simply prepared. Take a small amount of mushroom (refrigerate the rest) and sautée in a little butter and garlic, and don’t mix different types together. If you react badly to a mushroom you won’t have eaten a whole heap, and you will know the specific mushroom you ate. Some caution also needs to be taken not drink any alcohol if you eat inky caps... but that’s another story.
Allergic reactions aside, the oyster mushroom has long been used as a medicinal edible in asian cuisine and culture. Recent studies indicate that oyster mushrooms are beneficial in reducing cholesterol and boosting immune response. Oyster mushrooms are full of amino acids, and vitamins making it an all round good for you food.
As a culinary item oyster mushrooms are a beautiful treat. They have a very light, fruity smell and taste and their delicate buttery texture lends itself well to many dishes. Add oyster mushrooms to soups and stews and the trimmings to a simmering pot of vegetable stock. They are beautiful with chicken or pork and are lovely incorporated into your stuffing recipe or mushroom gravy. As they are a common ingredient in Asian cuisine, add them to any Chinese or Japanese dish requiring mushrooms such as yakisoba noodles, fried rice, stir fry, or batter them as they are for a tasty tempura treat like we did this week.
Tempura Wild Oyster Mushrooms
Tempura is so simple, but the cooking method is temperature and time sensitive so make sure all of your ingredients are ready to go and your pan is hot before you mix the batter! If you can't find wild oysters, try looking for cultivated greys at a local Asian grocer.
1 cup flour (wheat, rice, or cornstarch)
1 large egg
1 cup cold water
1/2 pound of wild oyster mushrooms
Heat your wok or pot on medium heat and add 2-3 inches of vegetable oil for frying. Clean and pick over your mushrooms and check for worms and beetles, discard any wormy bits and woody stems. Test your oil to make sure it's hot enough to fry in and adjust the temperature if needed.
Mix the batter with a fork or chopsticks rather than a whisk to avoid incorporating too much air into it. Ice cold water is the best to use. I used my already freezing well water coming from deep underground and put the batter in the fridge for a few minutes between frying batches of oysters.
Dip the oyster mushroom pieces in the batter and quickly drop them into the hot oil. Fry until golden brown and flip them over if needed for even cooking. When ready, remove them from the oil and quickly toss them with sea salt before serving. Serve with a tempura dip or just lemon wedges to squeeze over them.
2 Tbsp soy sauce
2 Tbsp rice vinegar
1 tsp honey
1/2 tsp sesame oil