You can "clone" some mushrooms pretty easily. Oyster mushrooms and shiitake tend to be ageessive enough to out compete minor contamination (depends on where you live as to what contams are around). Make multiple slides. Pick the clean ones to move to grain spawn. One or two dishes in a quart jar of grain spawn. Don't expand too quickly/far - look for inoculation rates over 10% of the substrate mass when moving to fruiting substrate.

That said, just a dead air box/bag/room with lysol aerosol disinfectant (ethanol) for the trapped air and 70% isopropyl alcohol for surfaces is fairly effective. I'd be careful with fumes. I have a basic respirator like a 3M 5xxx or something.

I also tried a combination flowhood/glove box type thing. It works well if you have a new filter or leave it on. Otherwise, I think contamination just gets blown off of the filter once you do turn it on again.

I didn't mean for it to even go this deep. You don't need to actually culture the mushroom from scratch. You can buy syringes with liquid culture. Then just squirt it through the bag with sterilized grain spawn (pressure cooker can sterilize). Then transfers to the fruiting substrate can be done in a moderately cleaned room without any special devices using the aerosol and wipe alcohol with inoculation 10-20%. This is surprising effective, even for contamination prone stuff like lions mane (which I can never seem to culture from spores myself).

Yep, all of my amateur gourmet mushroom growing attempts have resulted in contamination sooner or later. The good attempts had several flushes before mold set in, the bad attempts created such foul odors they went straight into the compost (or garbage for the most offensive result)

Seems like creating an environment that certain funguses like but others don't is pretty tricky, and mostly relies on giving your chosen fungus a head start unless you can maintain perfect sterility.

> Seems like creating an environment that certain funguses like but others don't is pretty tricky, and mostly relies on giving your chosen fungus a head start unless you can maintain perfect sterility.

Yeah, all fungi like pretty much the same environment, so that's impossible but mushrooms need much more oxygen to grow. So it's important to have a lot of fresh air and a lot of humidity. Mycelium actually produces antifungal substances so it quite literally fights for domination of the substrate with others. The "trick" in any grow is to get as many flushes as possible until the mycelium gets too weak to protect itself. Keep in mind that the substrate is metabolised so it becomes less rich in nutrients over time, and mycelium is sitting in its own "piss" so to speak. So at some point it cannot fight other fungi anymore and substrate gets moldy. Even then, you usually have one type of mold winning over. It's pretty random what type of mold you'll get. I think it might be equally hard to grow one chosen type of mold as one type of mushroom...

Flow hoods for the win! You probably know that, but it should be said in case someone reading does not. If you can't buy one, diy a decent one, then keep the air in your workroom as stagnant as possible and cross your fingers.

The problem with flow hoods is that most people don't want to, or can't, leave them on indefinitely. Once theyre off, the air will carry contaminates to the clean side. That's basically what I realized after a DIY using setup that looks like an open front glovebox with a HEPA filter blowing air through it.

Yeah, I did a janky cardboard box and saran wrap glovebox when I tried to do my own innoculation... was a PITA to use, and contamination from that batch was worse than when I just went into a room with still air and crossed my fingers.

(didnt have HEPA filtered air blowing, that sounds like a good idea)

A big plastic tub with two arm holes cut out would be a much better solution.

And I hope by “glovebox” you mean a still-air box, because gloves attached to the box actually increase the contamination rate due to the box sucking in air when you move your hands.

yep, still air box is the correct term I think. It was a cardboard box with two armholes cut, and saran wrap stretched over the top.

Put all my equipment inside, stuck my arms in to more or less plug the holes, then sprayed a bunch of rubbing alcohol all over the inside, then got to work. The ergonomics were horrible, my back got tired, and I'm pretty sure my arms didn't plug the holes very well and I assume they effectively were pumping air through the system by the end of it as I got sloppier.

Definitely will do something better on any future attempts, haha

The easiest technique is getting a big plastic tub (>90 qts) from Walmart or Target, heating up a coffee can on the stove, and burning the arm holes in the side.

"The good attempts had several flushes before mold set in, "

Many of the commercial kits will grow mold after a few flushes too. Many will only guarantee a first flush. One trick I've heard of is leaving the block in an area with a lot of freash air movement after each flush, even placing them outside.

Commercial shiitake kit got mold on second flush, so I buried it in a raised bed. Nothing happened for a couple weeks, so I stopped checking it regularly, but then found a HUGE (unfortunately old) mushroom (and a few normal sized ones) growing from that spot about a month later. I think burying after first flush might be the best way to go - soil manages moisture and gas exchange needs pretty well already.

Excited to try growing stropharia wine caps soon! PNW is great climate for having a bunch of wood chips on top of garden beds anyways :D

True. If going the outdoor route, shiitake logs can be a good option too. Depends on how much space one has and the options for sourcing the logs.

Careful with invasive species. - also, sounds awesome - if you document your process maybe post a show HN