For way too long I have been telling people I was going to explain how I grow most of my fungi.
I used to have all kinds of contraptions like glove boxes. This really gave me the shits so don’t bother any more – nowadays I just use good sterile technique and don’t get many contaminations. I accept the occasional contaminations in favour of the ease of production. I also H2O2 in my agar too.
Using COLES budgie seed bring to the boil the desired amount of grain with an excess of water. Once boiling check the grain every few minutes until the largest grains are good through - you can check this by breaking open some of the largest grains. They should be fully hydrated with no starchy centre. Once cooked rinse the grains until the water runs clear. Any broken grains that can make the mass too sticky will be washed away during this process. Drain the grain overnight. The grain should separate individually and not be sticky.
Fill normal jam jars ¾ full with grain and cover the opening with Tyvek. Foil can be used to hold the tyvek on the jars.
Load the filled jars into the pressure cooker. Cook at pressure for approximately one hour.
Once the pressure cooker is finished and returned to normal pressure take out the hot jars and carefully shake to break up the grains. Place them somewhere clean to cool. At the jars cool they will suck air into the jar - placing them in a clean box will minimise the chance of contamination.
Once cool (or at least below 40C) you can add mycelium from agar plates. One, one litre jar I find needs about 4 or 5 little chunks of agar. It doesn’t really matter how big the chunks of agar are. Once you have added the agar the jars should be shaken to mix the agar. With a sort of rolling action you can mix the grain until the agar is mixed throughout the jars. This takes some practice.
Once the jars are mixed remove the foil from the lids and tape the edges of the tyvek onto the jar. I use standard sticky tape. And wrap it around the jar mouth a few times. Excess tyvek is trimmed off. The tyvek lid is then sprayed and wiped with 70% metho. A fresh foil lid is placed on the jar.
The jars are then placed somewhere clean and warm to colonize.
Once the jars are 30% colonized (approximately) they can be shaken again to mix up the grain then placed back into incubation. This speeds up the final time it takes to complete the spawn.
Once the grain is fully colonized it is ready to use.
Preparing the substrate
There are a number of substrates available for growing oysters (wood, straw, paper. Coffee waste) basically any course plant material that can withstand a soak and a pressure cook can be used. The ideal choice of substrate depends on the species grown but to keep this guide generic I provide two examples.
Recycled newspaper finely chopped or paper cat litter : 10 units dry
Wheat bran: 1 unit
Full fat milk powder 0.1 unit
The paper is soaked then squeezed to expel excess water - the substrate should be saturated but not have any excess water pooling. Pour boiling water over the bran, carefully squeeze out the bran and mix with the paper. Add the milk powder and mix well. Stuff the mix into oven bags. Bake at 140 for an hour, turn off the oven and leave to cool over night. When cool in the morning add a good amount of spawn (half large jar, maybe 300mls) while maintaining good sterile technique. Seal up the bags with sticky tape and massage the bags to mix the spawn if you are using oven bags its worth taping down the seams of the bag before you massage, I find they often split at the worst times. Move to a dark warm area to colonize. Wait a week and check how it’s going. If you have areas that don’t want to colonize you can try making some holes in the bag to provide gas exchange. There is some gas exchange through the bag wall but not really enough for healthy growth. (Sterile filter patch bags are a perfect for this) once colonised move to a fruiting area - depending on the species this could be outside under a bush, in a terrarium or hanging in the shed.
I have used this paper recipe for a number of different fungi including oysters, shiitake, Ganoderma, Hericium & Agrocybe. It’s a good one. ;)
Straw. My favourite because it is easy. This is good for oysters and can be done on a huge scale.
Bran : some ?
Get a bale of straw, a couple of mates with eskies (or large drums) and a chainsaw. If you are careful you can slice 1 inch sections off the bale until you get to the strings holding them together. It’s a messy job but it is fast. Hedge trimmer also work pretty well.
Once you have a huge pile of straw, stuff it into the eskies and pour over hot water aiming to get a final stable temperature of 65 - 75 degrees. Leave it for an hour.
After an hour carefully empty out the water and throw the straw onto a table, throwing it in the air helps cool the straw - you need to spread it around to cool. You can do the same on the floor on a tarp depending on how much you have. The soaking also hydrates the straw so it can be heavy. Once its cool to the touch ( I would guess at about <40 degrees you start stuffing it into a fruiting container, I like to use plastic bags but washing baskets & bins are also good. The plastic ones with big holes are good. I find having a bucket to hold the bag helps with the stuffing and stops the bag from tearing. Stuff a layer on the bottom of the container- pack it down, add some bran (soaking in boiling water first) and then some spawn, more straw, bran, spawn etc until the container if full. Once full either tie up the bag or put the rigid container in a bag. You are trying to keep the moisture in the bag but don’t worry if there are some gaps.
Leave somewhere to colonize. It should be obvious when it’s colonised by having a look. Once it has colonized remove the bag from the washing basket or poke some holes in the plastic bag to increase gas exchange and stimulate fruiting. Again they should be moved somewhere where the conditions suit the species. With straw, the mass of the block maintains moisture to the fruit so you can keep them almost out in the open. I hang mine in a shed. As long as the temperature is about right for the species they should fruit in under a week.
Once the blocks slow production I bury them in the garden where they continue to fruit. If you have a mulcher, make some piles of mulch and add the spent blocks. I have piles of mulch that fruit now and then around the garden and plants. It’s a great way of introducing fungi into the garden for soil improvement and a larger harvest.
There are lots of ways of growing fungi - this is just the way I do it. It’s probably not the easiest or cheapest way of doing it butI have found it reliable and it works well for me.
if anyone has any comments or suggestions please add them to this thread.