White powder around your oyster kit
A thin, dry white powder around or under an almost mature oyster mushroom is spores, not mould. It is a sign that you can harvest. If you want fewer spores in your home, harvest a little earlier.
GroCycle (VK) · BS-43Spore drop is part of ripening, especially in oyster-type mushrooms. It only appears once the caps are well developed.
GroCycle (VK) · BS-43Spores or mould?
Spores lie as a thin, dry powder under a mature cap and no longer change shape or colour. Mould usually starts earlier, on the substrate itself, and spreads or changes colour.
GroCycle (VK) · BS-43What do you do?
Throw nothing away. Harvest soon, while the cap edges still curl slightly. Harvesting too late gives curled-up caps and more spore dust.
GroCycle (VK) · BS-43Spores and your lungs
An allergic lung reaction to inhaled spores has been described in professional oyster mushroom growers. No risk measure is known for a single hobby kit. Harvest on time, do not grow in a bedroom and ventilate. If you repeatedly get a fever, a cough or shortness of breath, remove the culture and see your doctor.
PubMed PMID 3169217 · BS-61PubMed PMID 10024747 · BS-62NCBI Bookshelf · BS-60Source
- How to harvest mushrooms — GroCycle (VK)
- Hypersensitivity Pneumonitis (StatPearls, Chandra & Cherian, bijgewerkt 10-07-2023) — NCBI Bookshelf
- Extrinsic allergic alveolitis in oyster mushroom growers (Eur Respir J 1988) — PubMed PMID 3169217
- Hypersensitivity pneumonitis outbreak in oyster mushroom indoor cultivation (Occup Med 1998) — PubMed PMID 10024747
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This is general growing information from the sources listed. Always follow the instructions of your kit or supplier. Only eat what demonstrably grows from your own culture of the bought, named species; if in doubt about colour, smell or shape, do not eat it.
This is not medical advice. If you repeatedly get a fever, a cough or shortness of breath while growing indoors, remove the culture and see your doctor.
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