Written By Mitchell Yu
Many strains of mushroom can tolerate a wide range of temperatures. It’s possible to successfully fruit them when it’s snowing outside and also in temperatures above 30 degrees Celsius. I’ve had success fruiting mushroom in containers in my house during very hot summers where temperatures reach over 40° C outside. I find that mushroom do well in low temperatures, however, they grow a little slower and often produce less but larger mushrooms. In really hot temperatures the mushrooms grow quickly, but you need to be diligent about contaminants.
The main requirement for fruiting mushroom is they need a high humidity environment. This can be achieved using several low-tech methods described below. Unlike other popular gourmet mushrooms (e.g. oysters), mushroom are fairly tolerant of high CO2 environments, so you don’t need a lot of air-flow in conjunction with the high humidity. Refer to end of document for Detailed Grow Scheme.
Preparing your block for fruiting
Approximately 1 week before you’re ready to eat your mushrooms, give the block a good whack on each side with your hand. You’re aiming to hit it hard, but without breaking it. About the same strength that you’d pat a large dog. This simulates a log falling and shocks the mycelium into reproducing (creating mushrooms).
2. Fruiting in a Bucket
What you’ll need:
· Large bucket
· Brick or anything to elevate the Mushroom Block
· Tea towel
· Hand Mister
Gently cut open the mushroom block, ideally over a sink or outside as there may be residual water may leak. You can either gently rinse the mushroom block exterior or dunk the block in water for 2-5 seconds.
Once the tub is clean, it’s simply a matter of placing your block in the tub and then opening it once per day to give it some air and a few quick squirts with a hand mister. You can take the lid off the container and use it as a fan to help get some get some oxygen in. I find that this method works better when the weather is warmer, as liquid is less likely to pool in the bottom of the container. The main problem you’ll have with this method is bacterial contamination. The block will continue to exude metabolites (brown liquid) that are susceptible to contamination, especially if the block is sitting directly in them. One way to avoid this is to do the same thing as the bucket method and place a brick in the container with water underneath. The liquid metabolites will disperse into the water and you can dump out this dirty water when you are ready to harvest.
Another method that works quite well is to skewer the blocks on spikes in the container. This keeps the blocks off the bottom of the container and prevents them from sliding around or toppling over. It allows you to arrange the blocks to maximize fruiting space.
Raising mushroom reduces contamination
You can place the container inside or outside, as long as it’s not in direct sunlight. It’s fine to get a bit of morning sun, especially at the end of autumn, winter and the start of spring.
Pros:In my experience, this is the easiest way to get high yielding mushroom crops. The clear container also means that the mushrooms will get some sunlight and contain more vitamin D.
Cons:Can contaminate more easily if tub isn’t clean, wrong time of year, or tub not opened periodically to allow in some fresh air. To make these more efficient we can add holes and fill with Polyfill/Filter material to allow Free Air Exchange (FAE).
Checking in on your mushrooms each day
For the first few days, open the fruiting container and give the block a couple of sprays with your hand mister. You want to wet each side of the block if starts to look like it’s drying out. In a few days you’ll see mushroom pins (baby mushrooms). Keep misting the blocks each day for a few more days and then stop misting when the mushroom pins start to look like proper mushrooms. If you mist the block as the mushrooms get larger, they tend to stay wet and have a reduced shelf life after harvesting. Within 7-10 days after placing your block in a container they should be ready for picking. The mushrooms should be doubling in size every day, once they stop growing it’s time to pick them!
Second flushes
Most of the time I don’t bother trying to get a second flush of mushrooms from mushroom. This is because the yield will be fairly low if your first flush is large. If your first flush is small, or you want to maximize yields, do the following:
When you’ve picked the mushrooms from your first harvest, leave the block somewhere to dry out that has good airflow (e.g. on a shelf with a rack). You’re trying to prevent the outside of the block from going moldy. After 3-4 weeks the block should be very dry, submerge it water for approximately 12 hours. One way to do this is to fill a bucket with water, submerge the block in it and place bricks or weights on top to hold it under water. The idea is to hydrate the block so that it gets wet, but not so wet that it falls apart. Take the block out of the water, hit it on each side again (not too hard as this time as it doesn’t have the bag to hold it together) and put it back in your fruiting container. Repeat the misting routine, there’s no need to put it in the fridge this time.
Disposing of the block
Your mushroom log is completely organic, you can compost it, bury it. You may hit the jackpot and have garden mushrooms.
Dealing with problems
The two biggest problems you’re likely to face is that your block will go moldy or you won’t get many mushrooms. If your block is going moldy, it’s too wet and potentially doesn’t have enough airflow. If you’re not getting a good yield, it’s likely the block is too dry and you need to increase humidity by misting it more. It takes a little bit of experience to know what looks right, if you’re unsure it’s better to err on the side of keeping the block a bit drier. It’s better to get less mushrooms than no mushrooms at all.
Mitchell Yu