Get answers to 5 most frequently asked questions about mushrooms. In this post, I will focus on one of the five questions that you’ll commonly find either on a home gardening blog or mushroom lovers Q & A forum page – How long do spawns last? The 4 other key questions will form the major themes to spark of discussions right here at mushroom source in my subsequent posts this month.
- Can you help me Identify a wild mushroom?
- What is the difference between a toadstool and a mushroom?
- Can mushrooms grow in a room with an AC?
- What do you do when your mushrooms aren’t growing
Let’s get Started: Spawn is a living product!
Your spawn or what I literally call the mushroom seed can last for
as long as you decide. It all depends on
- the strain
- the storage temperature
- and more importantly,the way it is stored
1. The strain:
Strains – could be sorghum, millet, barley etc. but strains with slowly growing mycelium have the longest shelf-life. Based on appearance, the signs of the ageing process in order are:
- mycelium becoming more compact
- formation of skins, crusts and lumps
- production of colored fluid with an unpleasant odor
autolysisor self destruction of the mycelium and disintegration of the spawn.
In the first two stages, the mycelium is perfectly useable, although it is less crumbly than totally fresh spawn. Since the autolysis (=self-destruction) of the cells begins at the end of stage (3), it is recommended to use the mycelium before that time. In stage (4) the mycelium is dying and should be eliminated.
2. The storage temperature:
The ideal storage temperature for most strains of spawn is 0 to 2°C. At this temperature the spawn can be kept for 2 to 4 months. There are a few exceptions though:
- Pleurotus salmoneo-stramineus and
- Agaricus “blazei” which can both store at ± 10°C without any grave consequences.
3. Storage method:
Another exception are spawn plugs (dowels): they keep much longer, at the same temperature of 0 to 2°C. Depending on the strain, plugs can be kept for 8 months to 1 year.
To prevent overheating, never store complete pallets in the cold storage unit. Place the boxes on shelves, or stack them in an alternating manner like bricks, always being sure to leave ± 10 cm space for air flow between the boxes. For Oyster Mushrooms or other exothermic species spawns that will be stored for longer periods, should be taken out of the boxes or spawn kits and put separately on shelves in the cold storage unit.
Since good air circulation is very important for uniform refrigeration and spawn survival, the cold units should be opened daily for ventilation.
Truth is: most mushroom growers at home pre order for ready made spawn because of technicalities involved in producing it.
Extra Helpful Tips for When your Spawn Arrives!
- At Mycelia’s ( or spawn labs.), the bags of spawn are individually refrigerated at 0°C and packaged for shipment at the last moment and the temperature of the spawn on the pallets is usually taken just before shipment and indicated on the shipping bill.
- In order be sure that the shipping was correctly carried out, and to have evidence in case of dispute, the temperature should be taken again upon arrival, and indicated on the same bill.
- If your Spawn is to be stored months before use then it is advisable to hod on till you’re ready. The extra shipping costs will be largely compensated by the extra yield and/or the lower production risk.
- Each package of spawn carries an identification label on which strain number, line and inoculation data are specified. Please keep these references in your production records to allow traceability whenever necessary.
Read more on the growing mushrooms page