Blue Oyster Mushrooms (Pleurotus ostreatus var. columbinus): the First Harvest

If you’re in the market for immediate gratification, consider an oyster mushroom kit.  I’m harvesting mushrooms twelve days after I started growing them.

Oyster mushrooms (there are several varieties and subspecies) are some of the most nutritious around. According to R.H. Kurtzman, PhD., they are rich sources of high-quality proteins and amino acids, B vitamins, and pro-vitamin D (the vitamin a lot of people are missing these days, as indoor jobs means little sun exposture).  Minerals such as iron and potassium are also present. And oyster mushrooms are high in chitin; he recommends them as a cleaner source for chitin than shellfish.

Medical studies show  benefits of oyster mushrooms. They’re  a good source of glucosamine, which often helps people and animals with joint problems. (Glucosamine works very well for some, but not others ) Several studies are now showing that oyster mushrooms lower cholesterol.

Besides these benefits, blue oyster mushrooms were my choice because they can grow at temperatures cooler than other oyster mushrooms: from 45F (a little over 7 degrees C)  to 65 degrees F (about 18 degrees C), and aren’t hurt by freezing. In my uncentrally-heated house, with a trip coming up, this sounded good to me. The mushrooms fruit at 65 degrees, which sounded about right for a cool place in my house this time of year. The final appealing aspect of this type of mushroom is that they looked like some of the easiest, quickest mushrooms to grow.

I reported earlier that I’d done some studying of Paul Stamets’s Fungi Perfecti catalogue, and ordered some mushroom plugs and a kit. A kit’s the easiest possible way to grow mushrooms, as the grower has done all the work in getting the mycelium in their right growing medium and ready to go. You just activate it by keeping it moist in dim light.

It was only a couple of days before I started to see the primordia poking through the microscopic holes in the growing bag (some professional mushroom growers use floor-to-ceiling-long versions of these bags, making little forests of them in their growing rooms).

In a day or two, the forming clusters looked like this, close up:

As they got bigger, my blue oyster mushrooms weren’t particularly blue; maybe this is because I let them dry out too much (apparently that can turn mushrooms brown), or get too much light (mushroom colors are darker in dim light, paler in sun).

Keeping the mushrooms moist enough has been hard; I’m starting to understand why there are special mushroom growing rooms. Mushroom kits need to be in a place prominent enough that I will notice and water them every day - but if that place is too light, I run into problems. If  it’s dark, it’s a lot easier for me to forget. While my wood stove leaves some nice cool spaces in my house where I can put plants that don’t like heat, it also dries out the air, as all heating systems do. If you had a house with a basement, that might be ideal: I could keep my mushrooms outside, where they’d get all the natural humidity, but I’m not sure whether they’d fruit, since the temperature needs to be at 65 F for that.

We had a good rain, so I did put the mushrooms out for a day or two to catch rain water, on the theory they’d like it as much as plants do. I’m not experienced enough to know if this slowed down the fruiting, or helped it, but it did mean they were as moist as they like to be for a couple of days.

Some mushrooms, like morels, are temperamental; you could wait two years to harvest those. But I got my first blue oyster mushrooms eight days after I started spraying it with water and cloaking it in its humidity tent. In fact, I might should have harvested them a little earlier; the information-packed pamphlet that comes with the kit shows a picture of ripe mushrooms as being still a little convex (I always have to remember: concave is caved in; convex is the one that bulges out, like those old bull’s eye mirrors, or a bulldog’s eyes).

Some of my mushrooms had definitely lifted their caps up and started to make cups, like this:

That’s when the mushrooms have apparently gone past their prime. Still, they didn’t look so bad, so I harvested them, too, with my little pointy flower shears; I got about a double handful in all, leaving many small and tiny ones still growing and popping up. Commercial harvesters gather oyster mushrooms by the bunch, but I have the time to be a little more conservative; I hope to grow all my mushrooms to their full extent.

I think some of the reason I let my mushrooms go was that I had an inner picture of the caps opening out from the closed cups to a flat spread; I see now that I was basically transferring the image of an opening bud to the mushroom world. Note to self: mushrooms don’t act like chlorophyll-bearing plants. You knew this.

The Fungi Perfecti pamphlet recommends cooking oyster mushrooms a lot longer than I have in the past. They cook down quite a bit, to half their fresh volume, or maybe less.  That’s okay: now they have nearly 20% protein and .1% niacin, among other vitamins.  While the pamphlet sugggests sauteeing in olive oil for 10 to 15 minutes, then adding butter, tamari, chopped scallions and wine, I’m taking a simpler course for now.  For reasons I’m too polite to mention in a blog, I can’t eat olive oil, so I sauteed the mushrooms in walnut oil (my standby oil for cooking and baking: it always tastes great, and has those healthy omega-3s). The rest of the recipe sounds great, but I didn’t feel like rushing out to get the missing ingredients.

So, using what I had, I sauteed the chopped mushrooms with chopped onions in walnut oil, until the mushrooms were golden brown. A great sauce on white fish, and it made rice and beans taste like a gourmet treat.