Shiitake mushrooms are the yummiest variety, in my opinion. They’re also the most expensive in the shops, and it’s virtually impossible to find organic ones, at least where we live. Solution: grow your own.
You’ll be happy to hear that making your own shiitake mushroom log is very easy. It would make a great holiday project for any family, or a great skill-share workshop in your community. Here’s how you do it.
Making a shiitake log:
- one recently cut log – ideally 100–150 mm in diameter, and preferably no less than 600– 750 mm in length
- shiitake spawn (plugs or sawdust)
- hand drill
- beeswax (organic, if you can)
- mallet – preferably with a rubber head
- heat source and saucepan
Photos by Cathy X
The log: A freshly cut log is best, as this means other fungi haven’t yet had a chance to colonise it (and less competition means more shiitake mushrooms for you). ‘Fresh’ means cut in the last week or so.
You can use various woods. We use a thin-barked eucalypt called ‘snappy gum’ (Eucalpytus rossii) which works well. Traditionally, oak logs are used.
The holes: We drill each log with 20 holes, evenly spaced around the log, width 8.5 mm if you’re using standard plug spawn (see below) – the diameter of the dowel plugs increases from swelling in the moist environment.
If you’re using sawdust spawn, the holes can be bigger. For example, you can get a small hand tool that injects a chunk of sawdust spawn snugly into 12 mm holes.
The spawn: The basic idea is to fill the holes in the log with shiitake spawn (mycelium). Plug spawn – shiitake spawn that has colonised a wooden dowel plug – is one way of doing this. Colonising sawdust with shiitake spawn, and putting that in the holes, is another way. We use plug spawn.
Inoculating the log: This is the fun part. You take a spawn plug and tap it into the hole, and repeat until you run out of holes. Ta da! One inoculated log.
Sealing the log: This step is to ensure that you actually get a harvest of shiitakes, and not some other crazy fungi.
To ensure that other fungi spores, which are always floating around in the air, don’t take over your carefully prepared log and out-compete your shiitake spawn, you need to seal all open surfaces on the log.
The best way to seal the log is with beeswax, as it’s the most natural substance for the job. The mushrooms absorb whatever they come into contact with, so obviously you don’t want to use petroleum or artificially based waxes or sealants on your food.
In a perfect world you would use organic beeswax, as beeswax is a bio-accumulator for whatever toxins the bees have encountered (and most conventionally-managed bees encounter quite a bit, both in and out of the hive). If you can’t, just go with whatever beeswax you can get. It’s still the best option for this job.
So melt down some beeswax in a saucepan, and apply it anywhere the log has been penetrated. Don’t forget to seal each end of the log where it’s been cut, as well as each hole.
Siting your log: Hurrah! Your log is prepared. Now for the waiting bit. Take your log and put it somewhere with good airflow in the shade. Keeping it moist is good, but the shiitake mushrooms will fruit even if the log is not constantly moist, as long as it doesn’t completely dry out – it will just take longer.
If you have a tree, put your log up in the branches, or close to the tree somehow. Make sure you keep it out of contact with the ground.
In four to eight months, depending on the weather, you should see the mycelium start to colonise the ends of the wood. Now it’s time to knock and dunk your log.
The knock-on effect: This kind of mushroom grows on dead wood, and dead wood on the ground has fallen. So you can simulate the mycelium to proceed into a state which will result in a ‘flush’ of fruiting mushrooms by giving your log a good thumping. Pretty cool, eh?
Dunk it: While not absolutely necessary, in a dry climate like ours we find that dunking our shiitake logs helps stimulate fruiting. We dunk the logs for 24 hours in an old bathtub.
Harvest: Soon your logs will start ‘pinning’ and you will be able to see the shiitake mushrooms emerging, like little bumps down the log.
At this stage, prop the log up for good airflow so that shiitakes can emerge from all sides. Give it a misting with water daily (if you’re in a dry area) and prepare to harvest!
Kirsten Bradley runs Milkwood Permaculture with her husband Nick Ritar. Milkwood teaches gourmet mushroom cultivation courses in Sydney and beyond, and their blog has lots of mushroom cultivation resources – see www.milkwood.net