I’m trying my hand at growing oyster mushrooms scratch for the first time. I’ve only ever grown stropharia in the yard and only experience with oysters was using the premade grow kits. I wanted to try spawning my own substrate this time. I pasteurized straw and innoculated it with sawdust spawn from Mushroom Mountain. It put them in small plastic bins, kind of like a mini laundry basket and then into plastic bags with holes poked all around. It’s been a few weeks and I’ve yet to see any signs of growth so I peeled back the plastic and saw this fuzz all around. Being a novice with oysters, I’m not quite sure if I’m looking at mold or is this what it should look like. There’s two bins in the pictures below. Any help would be awesome. Thanks!
hard to be sure from your photos, you might want to use two forks and open a fissure in the substrate to see if you do indeed have the white threads of mycelium growing.
You didn't mention anything about how you sterilized those bins (you did do that didn't you?).
When you are starting from a prepared spawn, everything needs to be sterile to prevent cross contamination. [this is standard procedure for any time you are trying to grow fungi, bacteria, etc.]
Most folks do their inoculations inside a laminar flow hood which prevents accidental contamination.
To test if that is mold, take a sample with a sterile loop and rub it on a piece of slightly moist bread, if it is a mold, it will grow quickly and take over the bread if just a day or two at 74 f.
Grow bags are easier. You can sterilize the straw instead.
You should be almost ready to fruit.
posted 11 months ago
Thanks for the feedback everyone! I took two forks as suggested (dipped them into a pot of boiling water for a few minutes first) and dug around. No mycelium to be found. I has pasteurized the straw by boiling for an hour but temps were unknown though, no thermometer handy. As for tools from latex gloves, to scissors, to the bin, all were wiped down with rubbing alcohol before it touched anything.
I think I’ll wait about another two weeks and dig again just to be sure as to not waste a good slice of bread. Deep down I’m thinking it’s mold too to be honest. I guess I’ll stick to the stropharia in the yard this spring. Just thought and heard that oysters were supposed to be very easy as well.
I second what Wayne says. Bag it next time.
The holes are so big! Water will evaporate, unwanted spores will move in. I've used bin bags and poked holes in them with a knife.
Maybe shove the whole thing in a big bag and water it quite a bit and poke holes? But don't take it out of the basket it's in. You might disturb the growth process. Just wait a bit longer.
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Proper sterilization for mushroom growing is done with steam and pressure, think of the sterilizing of surgical instruments.
Wiping down with rubbing alcohol doesn't actually kill any spores or even bacteria unless you let the alcohol linger on the instrument(s) for at least 30 seconds.
Since I doubt you have an autoclave (and why would you unless you're into microbiology), the best substitute is a pressure cooker fitted with a pierced plate to keep the implements out of the water in the bottom, 15 minutes at 10 psi kills everything.