To get started growing oyster mushrooms, here’s what you’llneed:
- A one-gallon plastic bucket with a lid. They do not cost much, but you may even be able to source them for free; perhaps ask a local restaurant for containers that might have held, for example,pickles.
- A substrate for the mushrooms to grow on such as straw, which is widely available and verycheap.
- Blue oyster mushroom spawn; we recommend grain spawn, which is nice and easy tohandle.
- Some surgical tape and an old pillowcase (to be explainedbelow).
Prepare theBuckets
Let’s start by preparing the buckets. You’ll need to drill holes in the sides of the buckets. Drill one row of holes set fairly close to the top of the bucket and a lower row about two-thirds of the way down. The holes themselves should be between 10 and 12 mm in diameter or exactly half aninch.
Take a moment to sandpaper any sharp edges so they’re nice and smooth. Then, drill some smaller holes across the bottom of the bucket for drainage; this will prevent excess water from pooling, which could create unpleasant conditions for thefungi.
It’s also possible to buy special mushroom growing bags, but by drilling your own bucket like this, you’ll, of course, be able to reuse it time andagain.
You could also scale things up by using, say, a five-gallon or 20-litre bucket. For something this smaller, drill up to 20 holes, spaced about six inches or 15 cm apart in each direction, which in this case would mean four staggered rows along the height of thebucket.
The holes not only ensure good air exchange, but they’ll also be where the fruiting bodies themselves eventually emergefrom.
Prepare theSubstrate
You can find straw in many places. A pet store is a good source as the straw will be clean and, crucially, come sliced up into small pieces. The smaller the pieces of straw, the quicker the ‘roots’ of the mushroom—the mycelium—will colonize it. Any straw will do, and you could even break up a full-sized straw bale, but you’ll need to chop it up into smaller pieces using, for example, a brushcutter.
To ensure trouble-free growth, free of contaminants or weed fungi, you could pasteurize the straw, and this is where that pillowcase comes in. Stuff the straw in a pillowcase and then plunge it into very hot water. Of course, use anything that will hold the straw: a net bag or an onion storage net, forexample.
The water temperature should be between 140 to 175 Fahrenheit or 60 to 80 Celsius. This will kill off most of the microorganisms but leave some of the good guys—the beneficial bacteria—intact, which will help the mushrooms to grow. (To completely sterilize the straw by boiling it up and annihilating every single living thing would, perversely, leave the straw open to infection from contaminants. Pasteurizing in hot—but not boiling—water offers us a sweetspot.)
Tie it off and pop it into this large stock pot or water bath of hot water. Check the temperature so it’s at the upper end of our temperature range, and add little blasts of heat, as needed, to keep it above our lower end. (If you have a jam thermometer, that’s handy for measuring water temperature.) Weigh the straw down so it’s completely submerged. This now stays in here for a fullhour.
After an hour, drain off the straw. Just hang it up and allow all the excess water to drip off and everything to cool down to the touch, which should take half an hour or so. You want it so that when you give it a good squeeze, barely any water drips out. The wet straw will be quite heavy—at least triple the weight of when it wasdry.
InoculationTime
Now for the real magic… inoculation time! But before we do anything else, we need to make sure we’re squeaky clean because any contaminants could compete with our mushrooms and spoileverything.
- Sterilize the bucket and your gloved hands with a solution of isopropyl alcohol or use asterilizer.
- Massage the bag of grain spawn to separate out all thegrains.
- Open the bag and layer up the bucket, starting with a few handfuls of that pasteurized straw… squash it alldown.
- Then, add a small handful of grainspawn.
- Then add more straw—another few handfuls—and morespawn.
- Continue adding until you get to the top. (As a rough rule, aim for between 5 and 105 spawn to 90 to 95% straw. You could use slightly less, but it will take longer and increase the risk of weed fungi takinghold.
- If you have any spawn left over, seal it up and put it in the fridge. It should stay fresh and ready to use for another month orso.
- After reaching the top, it’s on with the lid—also sterilized, ofcourse.
- Now, take the surgical tape. Cut off little squares of it and cover all of the holes on the walls of the bucket. The surgical tape is breathable and will do two things. It will keep the substrate and spawn protected from unwanted contaminants while still allowing free air exchange, and it will retain some moisture, keeping the humidity up, which fungilove.
- Finally, keep this at a comfortable room temperature, away from wild temperature swings. Over the next few weeks, the mycelium will spread out from the grain spawn and throughout the straw, ready for our next stage…
