WHAT IS GRAIN SPAWN?
Grain spawn can be thought of like “seeds” in mushroom cultivation. It is made by starting from either spores or a mushroom culture, which is then transferred to sterilised grain.
The mushroom mycelium then grows throughout the grain, feeding off the starchy goodness.
Eventually, the mushroom culture will fully colonise the grain, covering it in white mycelium.
From there, it can be broken up into individual grain kernels and mixed into a bulk substrate.
The mycelium will continue to grow from there- eventually producing mushrooms.
WHY DOES IT HAVE TO BE STERILISED?
Grain is highly nutritious- full of starch and sugars. When properly hydrated, it serves as an ideal food source for hungry mushroom mycelium.
Unfortunately, this also an ideal growing environment for mould and bacteria- which in most cases can grow much faster and stronger than mushroom mycelium. For that reason, the grain has to first be completely sterilised in order to kill off any mould spores or bacteria.
This is most often accomplished in a pressure cooker or autoclave by processing at 15PSI for 1.5 – 2.5 hours.
Pure mushroom mycelium added to sterilised grain has no competition, which allows it to grow and proliferate throughout the grain.
