The use of plastic bags in mycology is pretty common and, understandably, commercial operations want to ensure they are using the best methods to maximize growing yields as this will maximize profits, as a result, single-use plastic bag use is rife within the mushroom farming industry.
Plastic is a pretty versatile product, cheap, flexible and it can withstand a pressure cooker without breaking down.
However, these benefits also make plastic very bad for the environment and with the large drive-in environmental friendliness across the world this is one area where commercial mycology is falling short.
If like me you are just a home hobbyist OR just beginning your journey into mycology the use of plastic bags can probably be avoided.
This will benefit the environment and your wallet! Just like everything in mycology, all it takes is a little bit of trial and error, imagination, and persistence.
Growing mushrooms without plastic bags can be accomplished using a few different techniques, many common gourmet species can be grown inside jars, buckets and other reusable containers. The famous Monotub setup is a popular example which is regularly used by hobbyists. In parts of Asia Jars are used as one of the primary methods for growing gourmet mushrooms; however, this is often species-dependent.
To add to this I have done a bit of research on the topic and created a simple table outlining ideas for the cultivation of different popular gourmet species which do not require plastic bags.
|Reishi||Monotub, Jars, reusable containers|
|Lions Mane||Jars, reusable containers|
|Oysters||Jars, Buckets, Monotub (King oyster)|
|Shitake||Jars, Buckets, reusable containers|
|Enoki||Jars, reusable containers|
|Maitake||Jars, reusable containers|
|Cordyceps||Jars, reusable containers|
Each species will likely need a different technique based on their requirements.
Sometimes I will grow inside self-contained jars, sometimes I will inoculate grain spawn and expand into bulk substrates, really, it all depends on; the species, my free time and my goals.
Once you understand the general growing technique you can experiment on how to produce fruits from different species based on their growing requirements.
Always take into consideration how you are going to inoculate your substrates. Try to keep it simple if you are just starting out.
The larger the better, fill a jar with an appropriate substrate and inoculate with your chosen liquid culture or grain spawn.
The whole process can be self-sustaining and is probably the best for beginners as its easier to avoid contamination.
This method is common in parts of asia with the following species commercially grown: shiitake, maitake, nameko,shimeji, enoki and king oyster, however some of these strains are hard to come in the west.
For ideas fruiting the mushrooms in jars you can:
- Allow the mushroom to fruit out the top jar when 100% colonization is achieved by removing the lid. This technique is popular for Oysters, Reishi, Enoki, Maitake.
- Allowing the mushroom to fruit inside the jar as described here with the Lion’s Mane strain. This is also popular with Cordyceps.
- Remove the fully colonized cake from the jar and allow it to fruit in the open air (this technique is popular with shiitake) or a shotgun fruiting chamber (SGFC).
|Reusable.||Glass Jars can break.|
|Easy to clean.||The substrate can shrink causing some fruiting down the edges of the jar.|
|Easy to fill.||Not pliable (substrate cake make get stuck).|
|Easy to sterilize in PC.||Smaller Yields.|
|Set and forget.|
|Easy to innoculate|
Growing in buckets is a common method used to grow various oyster mushrooms. Substrate (normally straw) is pasteurized and placed into buckets containing several holes in the perimeter. Checkout How to grow mushrooms in buckets for a full breakdown on this method.
The mycelium will colonize the substrate and fruit out of the holes after several weeks. Yields have been shown to only reduce by 1/10th whilst reducing polyethene bag use exponentially.
|Stackable||Risk of contamination with some species.|
|Reusable.||Can take up a lot of space depending on size.|
|Commercial Yields Possible||Requires more growing steps.|
A Monotub is basically a storage tub which has been modified to produce proper fresh air exchange (FAE). It is filled with an appropriate bulk substrate and then inoculated with grain spawn. There is plenty of information online on how to set up and use a Monotub.
Reishi and King Oyster mushrooms are popular species which can be grown using a Monotub.
Reishi in particular will fruit inside the Monotub in an antler-like fashion and grow upwards from the base substrate like a forest.
Monotubs which are set up correctly can be relatively hassle-free and produce decent yields.
|Reusable||Can take up a lot of space depending on size.|
|Tons of instructions online for setups and use.||Not suitable for all species.|
|Set and forget if you get the airflow dialled in.||Requires more growing steps.|
It is possible to use reusable plastic containers of all shapes and sizes (which can fit in your pressure cooker). I will often find myself recycling takeout containers specifically because I like the shape and believe it could be a vessel for cultivation!
Look out for the 5PP symbol on the bottom which usually means the item can be used inside the pressure cooker.
I have used is this cylindrical soup container which I kept from my Korean takeout. This is now being used to grow Lion's Mane.
I have about 4 of these I can stack them on top of each other making a mushroom tower which doesn’t take up mush-room (sorry not sorry) in my growing space.
|Reusable||Can become misshapen in pressure cooker if holes are not made in container.|
|Free (if you recycled).||Requires more growing steps.|
|Stackable.||The substrate can shrink causing some fruiting down the edges of the jar.|
|Small or Large.|
|Easy to fill.|
|Higher Yield (size dependant).|
Do I need to wash the growing vessels with every use?
This is really up to you, but cleanliness is always the key when growing mushrooms. However, if your pressure cooking your vessels then this is less of a concern, always keep in mind which methods/strains are being used.
I like to keep my jars and containers clean, normally I will rub them down with soapy water and then alcohol just to be sure.
I always make sure to remove any mycelium which may have stuck to the inside or outside to help reduce the chances of contamination when reused.
I’ve seen trich grow on the tiniest piece of substrate on the outside of a lid which should have been removed.
What materials can be used in a pressure cooker?
Normally I look for containers which can fit in the pressure cooker (multiple at one time) and provide space to make inoculation simple.
Any plastic container which is made for storing food and labelled oven-safe or contains the 5pp symbol or higher can be placed into a pressure cooker.
Ensure a hole is made in the container or the pressure will misshapen the container.
Glass Canning Jars and other food-grade glass objects can also be pressure cooked, just make sure the items are room temperature before sterilizing inside to avoid thermal shock.
Something to consider when you find a container you want to use…
Make sure it is possible to create a hole in the container or the lid which can be patched up with micropore tape or polyfill to allow fresh air exchange (during the incubation/colonization phase the mycelium will require this).
How can I reduce the risk of contamination to my mycelium?
- Follow sterile technique during inoculation.
- Keep your growing spaces clean, this includes all your growing vessels and your growing space itself.
- Don’t keep checking on your mycelium constantly, YOU are likely to be the biggest spreader of spores and bacteria in the growing space. Wear a face mask and keep your hand clean while handling you grows.
- Follow instructions to a tee when sterilizing/pasteurizing different grains or substrates.
- Remove contaminated substrate from growing spaces carefully.
Personally, I enjoy using jars the most as I can inoculate straight from the syringe into the sterilized substrate without much hassle and very few contaminating. The mycelium usually takes over the substrate and fruits without much handling (however this is species dependent and will take a lot longer than usual).
For a home growing hobbyist it is perfect, but for a commercial setup, it could be lacking.
As I keep saying, experiment!!!!!!!!!