Shiitake mushrooms are delicious but really expensive. However, with just a little effort and some patience you can easily grow your own at home. Growing shiitake mushrooms needs little in the way of materials and work, and then you simply sit back and…wait. It takes time for the ‘mycelium’ (similar to the roots which support the growth of a tree) to develop, but once it does you should be rewarded with the first crop of many, eventually getting back between 1/4 and 1/3 the weight of the original logs in the form of mushrooms.
What you’ll need
Three (or more) fresh oak logs around 50cms long by 10-15cms diameter.
An electric drill and a 9mm drill bit.
A bag of inoculated wooden plugs.
A stick of beeswax, a safe way to heat it to ‘sizzling’ hot, and an ‘applicator’ to apply it to the dowel-filled holes in the log – basically a cotton ball held firmly with tweezers.
The logs are the most difficult thing to source, especially if you live in a city. Lumber mills mostly deal with softwoods, and finding fresh oak logs can be tricky. If you know anyone who works with forestry you’re in luck, otherwise rural lumber yards are a good bet. Or, you can buy them pre-inoculated from on-line mushroom dealers – but this is the most expensive option.
If you do find a source, the exact dimensions of the logs can vary. The important thing is that they are fresh (i.e. they haven’t had time to dry out since being cut), and undamaged, meaning the bark should be intact on the outer surfaces except for the cut ends. Check for discolouration in the exposed wood as this could indicate the presence of other fungi. If you find any, don’t use the logs.
Oak is considered the best, but many hardwoods will do so long as the bark does not crack or flake off over time, as this could allow the logs to become contaminated.
Inoculated plugs can be bought from Suttons Seeds. When they arrive, put them in the fridge until the logs are ready. The plugs will be somewhat white and fluffy, as if they’ve been packed with bits of cotton wool. This is the mycelium which will colonise the log and eventually produce mushrooms.
What to do
The idea is to drill a pattern of holes in the log, each approximately 1.5x the length of the dowels. This is somewhat more difficult than you might expect, as there is a tendency for the drill to suddenly bite and drill much further than you want. A drill stop will help this, if you can find one. If you can’t find a drill stop, find a piece of wood (50mm square is ideal) that’s about 50cms long, and drill a 9mm hole in one end. You then need to fasten the bit into place in the drill so that the amount of bit showing is 1.5 x the plug length, plus 50mm.
The log should be firmly held in place for the actual drilling process – and not by hand!
Place the 50mm section on the log so that the hole is positioned directly above where you want to place the first plug. Put the drill bit into the hole, and drill down into the log. The bit will only penetrate the desired amount. Then move to the next spot, and so on.
Don’t let go of the wood as you’re drilling, or it will be spun round, fast, and may damage you or the log. Use eye and ear protection, and…go…slowly. Don’t rush this. Drill holes roughly 10cms apart.
Sealing the plugs
Heat the beeswax so that it sizzles slightly on contact with a plug, then push a plug into one of the holes in the log and use the applicator to seal it shut with beeswax. Be very careful: heating wax is potentially dangerous and is best done without using a naked flame! Make sure all the holes are filled, and sealed – or you will be inviting contamination.
Harvesting shiitake mushrooms
Once the logs are done, it’s time to wait. Keep them somewhere cool and shady, and spray them with water every day or so to prevent them drying out. After a while – and it might be a long while – you’ll start to get mushrooms. From buying the spawn to getting the first mushrooms can easily take a year.
Clip the mushroom off using secateurs, as the stems are quite woody and not usually eaten. And then, it’s up to you. Shiitake mushrooms add a wonderful depth to stir frys, stews and soups, or just as a side dish. They can also be dried for storage.
If you don’t have access to oak logs you can buy a complete shiitake kit instead. These contain everything you need for a ‘windowsill’ crop and are an excellent way of starting to grow your own mushrooms at home.