Mycelium spawn is colonised substrate which can easily be transferred and re-distributed. Usually it comes in the form of colonised grains such as rye, millet and wheat but can also include wooden dowels and other natural materials. These seeds, once colonised can be used to grow mushrooms on many different substrates and in many different ways.
At Mediamatic we have the most experience making spawn of the following mushrooms -
Various Oyster Strains
On the following grains and seeds -
Assorted Grains - Bird food.
-- We have had little success with Rye. This is because it tends to develop a foul sweet smell after a few days of colonisation. We believe this is due to fermentation or resistant bacteria. We performed tests between different grain, and found that Millet and Bulghur tend to perform best, colonising faster and smelling far far less than Rye. --
Mycelium spawn takes a little while to make.
Firstly the grain has to be soaked, to allow it to be colonized quickly by the mycelium. The length of time needed to soak is dependent upon the grain, and whether the grain still contains husks or chaff.
For Buck Wheat, Bulghur and Millet, which soak up water quickly, it is possible to simply place the dry grains in a filter bag approximately 2 parts grain to one part water Eg. 250 Grams Millet with 125ml (As 1 gram of water is equal to 1 ml)
Bird Seed style - Bird seed is a fairly quick to soak grain, taking around 20 minutes of soaking and 5 minutes of boiling.
The soaked grain should then be put into jars or filter bags and then sterilised. Depending on the volume of grain this can take between 15 minutes to 1 hour 30 minutes of 120 degrees at 1.5 bars of pressure.
Inoculation can be done in different ways
Grain Transfer - This method uses existing spawn which is mixed with the sterilised spawn to colonise the new grain.
Spore solution injection. - This method requires using a syringe using spores which have been dissolved into distilled water. This can be injected directly into the spawn through the air filter.
Agar Transfer - Using slices of colonised agar, which can be dropped into the bag.
Spawn usually takes 1-2 weeks before it can be used to colonise other jars etc. The bags of spawn should be shaken once every two days to move the mycelium and ensure that the entire bag is evenly colonised.