Locomotoring

After 9 months, I tore down my miniature indoor oyster farm. I have harvested and dried several batches, enough to last me an year or more. Oysters are not my go to cooking mushrooms. They are beginner mushrooms for those who want to explore growing.

While I am far from being a seasoned mushroom grower, I now have the confidence to keep oyster mushrooms alive. Nine months ago, even that had seemed daunting. The growing kits are awfully expensive. And youTube university offers too many diverse options. In the end, I wanted something that would prove to be cost effective while being sustainable. In my wild mushroom foraging experience, cleaning the mushrooms had felt like a chore. So I had wanted a setup where the mushrooms would need minimal cleaning.

I went through a number of thought experiments before getting started. The eventual setup ended up being a steel table, topped by a clear plastic portable greenhouse (3 ft long, 2 ft wide and 3 ft tall), equipped with a 1.7L personal humidifier that turns on and off on a timer. The mushrooms were cultivated in four 2 gallon plastic buckets in straw media.

The only technical part (ie requiring tools) of this setup was to drill holes in plastic buckets. Our local ACE Hardware team equipped us with spade (paddle) drill bits – two different sizes, smaller one for the bottom and larger one for the sides. The spade drill bit doesn’t crack the plastic but often leaves a rough edge behind. Thankfully, mushrooms don’t mind these rough edges. I did try growing mushrooms in orchid growing pots, the clear ones with built in holes. Except these pots have too many holes and the effort of closing the holes with medical tapes became non-sustainable very rapidly.

Procuring straw in the middle of Bay Area proved harder than I had expected. Oyster mushrooms are forgiving, but they like the straw to be short. I eventually ended up buying straw seeding mulch from ACE to avoid the shipping costs on Amazon. It turned out that Oysters give a blind eye to presence of tack in the straw.

For six of the nine months, I pasteurized the straw in hot water. Eventually, the effort of pasteurizing started to feel like a chore. The last batch was prepared in slaked lime (Calcium Hydroxide). While I couldn’t tell the difference in mushroom yield or flavor, I did have a few blades of grass growing out of the straw with the slaked lime preparation.

Managing the humidity over the long cultivation period is perhaps the most common point of failure for all DIYers. I had started by spraying assiduously. But ultimately, a trip abroad came up and I needed an automation strategy. A tiny humidifier came to rescue. It took a day or two to adjust the frequency and timing, but otherwise, the humidifier has done an excellent job.

The steel table that I used for the purpose was originally bought for our kitchen. I wouldn’t have bought it for a mushroom growing exploration. But I was glad I had it. The environment is wet and damp enough that a normal wooden table would have warped and any other metal table would have rusted. The table top, along with the damp exposed portions of the greenhouse and humidifier, needed a through wipedown in between the cycles.

Each cycle would start with washing the buckets, wiping them down with alcohol, layering the bottom with paper towel, filling them up with prepared straw and existing spawn (store bought grain spawn or a small amount of inoculated straw from the previous cycle), compressing the straw and finishing up with a final layer of paper towel. For the longest time, I was putting medical tape on the holes along the sides of the bucket and I eventually stopped this procedure after 6 months. My setup didn’t particularly benefit from the tape.

Are the mushrooms tasty? Frankly, nothing compares to wild foraged mushrooms. Since I have been drying my oyster mushrooms, they have a pronounced smell of straw. It isn’t unpleasant but I would have preferred a forest smell. Harvesting at the right time has been one challenge. When they are growing, they grow so fast that lack of oversight for a day is sufficient to get them past their prime and smelling more straw like. While the greenhouse wasn’t sealed, and I had four stainless steel cooling racks to circulate the air under the buckets, a small fan on a timer can potentially help by adding short bursts of high circulation. Another experiment might be to hack the growing medium itself – perhaps adding wood chips can shift the aroma towards earthier tones.

Was the exploration sustainable? It lasted nine months, and I would give that a pass.

Was the exploration cost effective? Barely. I succeeded in getting two harvests per cycle, each cycle lasting about 8-10 weeks. The winter months were particularly slow – the farm was set up in the garage which has no insulation on two sides. I should have weighed the harvest but I didn’t. My best guess is that I harvested 20 lbs of mushrooms. To cover the total cost of this exploration (spawn = $40, plastic buckets = $20, straw = $25, drill bit = $25, greenhouse = $30, humidifier = $25, four cooling racks = $30, slaked lime = $10), the market price of 20 lbs of mushrooms would need to be $200. My local Whole Foods sells 20 lb at $400. Lets be generous and assume that my mushroom grower joy covered the cost of my labor. There were things I wanted to do but didn’t. One was to measure the temperature and humidity over the entire cycle. Another was to set up a photography kit during the growth phases.

Overall, I am ready to move on. Either to another non-mushroom based exploration or another variety of mushroom.