Job title: Pasteurisation Executive
Reports to: Chief Executive of Fungus Growing
As the Pasteurisation Executive, your job is to create a safe and uncompetitive environment for the fungal mycelium to grow. Yours is a pivotal role, as unpasteurised straw may contain other organisms that wish to compete with the mycelium for nutrients. You will be using hot water and handling a hot bag, so make sure you adhere to safe practices.
Duties & responsibilities
- Set up the equipment for safe pasteurising: bowl or bucket, plenty of hot water and all the kit contents required.
- Using hot water, pasteurise the straw in the plastic bag provided.
- Tie the bag up and ensure the straw is submerged for as long as it takes for the water to cool down.
- Untie the bag and drain excess water; pass over to the Director of Mycelium Dispersion.
- Take an active and constructive role in the team. This could include: helping to name your fungus once the mushroom starts growing; sharing photos and thoughts online; picking up the slack if any team members need a helping hand.
The science bit
‘Pasteurisation’ describes the process of killing bacteria or other microorganisms, usually in food. It is named after Louis Pasteur, a French scientist who in 1864 discovered that heating beer and wine stopped them from going sour, by killing off most of the bacteria that were causing it.
Pasteurisation is intended to kill off only some microorganisms, unlike sterilisation which kills off all microorganisms. Oyster mushroom mycelium is quite competitive when growing in straw and so it is not necessary to kill off all the other fungi and bacteria that might be present.
In the wild
Fungal mycelia naturally fight each other, and neighbouring bacteria, to defend their territories and keep invaders out. They produce antibiotics (chemical weapons) to fight against their neighbours and clear them out of the way. The winners in these battles can take over more territory and their mycelia are able to get larger. A larger mycelium usually means that more, or larger, mushrooms can be produced later on.
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