On January 20 of this year I announced my intention to start growing oyster mushrooms using a new non-sterile technique I read about in Fungi Magazine. The technique, perfected by Milton R. Tam of the Puget Sound Mycological Society of Seattle, WA, uses newspaper-based kitty litter and guinea pig chow in which to grow the fungal mycelium of the oyster mushroom. My first batch, started on that date is now doing great and is just a few days away from harvest. I will stretch this blog out a few days so I can give a full report including pictures, yield and cost per lb..
For the first few weeks not much was going on besides the relentless growth of the mycelium through the medium. Think of how soybeans are transformed into tempeh and you get the picture. Gradually the kitty litter turns white with fuzzy growth until almost no more is visible. This happened in a dark closet at less than 70 degrees F. After two weeks I brought the bag out and placed it on the kitchen counter. I waited a week and nothing happened. I looked up pictures on the web of “oyster mushroom primordium” to see if I was missing something. As it turned out, what I was missing was a little more light. The mushrooms need the light to trigger the fruiting process. I switched on a kitchen grow-light and set the timer for 12 hours/day, and that did the trick. Within a few days little white domes appeared in the bags near the holes I had cut. In a matter of hours the domes differentiated into pincushions and each “pin” then grew a cap and started to resemble a tiny mushroom. Each grouping now contains 50 or more individual mushrooms and each bag has about 4 of these groups. They are growing so fast I can almost hear them grow!
Milton Tam’s article said that the primordia would form “5-10 days” after the two week mark, and I was about to give up on day 23, exactly two weeks and 9 days after the start, when the buds first appeared. I have been mixing up bags once a week since the beginning, and I will mix more today. The goal is to have a steady supply; the next week’s bag will start to produce as soon as the previous is done. My big unknown at this point is how long the spawn will last. So far it has lasted almost a month in the fridge. I have attempted to inoculate more grain (wheat), hoping it will outlast the original.
Overall the project is worth doing. With less effort than making a loaf of bread I get a pound of premium mushrooms, although it takes 3-4 weeks. Once you get to the one month mark however, the reward is already sitting on the counter.
Oyster mushrooms are not only tasty, they’re suspected of containing anti-tumor chemicals. One study found they “inhibit growth of colon and breast cancer cells without significant effect on normal cells, and have a potential therapeutic/preventive effect on breast and colon cancer.” (International Journal of Oncology). Oyster mushrooms are rich in protein (up to 30 percent by dry weight), plentiful in B vitamins, have no cholesterol, and have significant levels of the cholesterol-lowering molecule lovastatin — up to 2.8 percent by dry weight (Stamets, 2005, Alarcon, 2003). If that’s not enough they’re anti-bacterial too! The first mushroom-derived antibiotic, pleuromutilin was extracted in the 1950s. This info on health benefits were taken from an article by mushroom guru Paul Stamets here. Paul also stresses that all mushrooms, including oysters, should be thoroughly cooked before eating. I couldn’t agree more; fungi are the chemical factories of the natural world and need to be respected for their niche; their nutritional and medicinal value is unlocked by cooking.
From mixing up the first bag until harvest took 30 days and yielded one pound. Since each bag took $3.92 in materials, that’s $3.92/lb. I fried up some this morning and had them in an omlet, it was great. Oysters are “al dente” mushrooms, similar to shiitake, not soft and supple like button mushrooms. There is a possibility that the bags will produce a second flush, so I’m leaving them around for a while. I harvested the second bag too but got only 10 ounces. I think this second bag was a little dry, so I’m planning on adding water to all future bags before they bud.
We just had another several inches of snow and spring seems far off, but the kitchen garden is going strong!