Most upvoted comment
You can pick your own mushrooms at this grocery store(r/mildlyinteresting)
Actually, in most cases it isn’t, but it is pasteurized. Sterilization would make the medium insanely contamination-ridden, due to the lack of competing microbes. Once mold starts growing, you’ve gotta toss the medium completely. While this is probably a nice hippy-dippy way to sell mushrooms, there’s no way it’s going to maintain healthy flushes for long with a “tame” culture like agaricus bisporus. It just can’t compete with molds like trichoderma, which is possibly the most common mold on earth. That’s not counting the possibly hundreds of people touching the growth medium, throwing their trash in it, discarding unwanted mushrooms into the pile, and the like.
I’ve read a lot about it (I was once an aspiring mushroom farmer) and I believe it has something to do with pressure+heat killing fungal spores, but leaving beneficial bacterial endospores intact. Essentially, the bacteria and other microbes take up real estate until the fungus shows up, and then it moves into their turf and consumes them as well.
The interesting thing is that in commerical mushroom grows, pasteurization temps are reached naturally due to the size of manure piles. The mass of the piles coupled with the immense activity of microbes within them raises the internal temperature to anywhere between 140f-170f.
Source: Paul Stamets, The Mushroom Cultivator and Growing Gourmet and Medicinal Mushrooms.
Edit Here’s some more places to find information about mushrooms, since I’m hardly an expert. I’m just a guy who reads a lot, essentially.
Those are the standard grow manuals, but if anyone has a suggestion for a more comprehensive or up-to-date manual, it’d be welcome. Mycelium Running is a great book if you’re just looking for a fun read about mushrooms.
/r/mycology – The subreddit devoted to mushroom growing and identification. Probably more relevant info here if you’re interested in growing mostly edibles.
Fungi Perfecti is good for equipment (I bought all my HEPA filters there, at the time they were the cheapest around). I think they have a YouTube channel too, and that’s got some interesting stuff on it.
Shroomery.org is a moderately famous mushroom growing forum, with a bit of a bent more toward psychedelics. However, I found tons of great people and information in the edible mushroom forum, and I received a few commerical grade cultures from a very generous member. There can be a bit of a circlejerk surrounding some “celebrities” that post there, but take what they say with a grain of salt, and always fact check against your grow manual. If you see something that looks stupid, it probably is, unless it works. Edit: I don’t think Reddit likes linking to the Shroomery, removed the formatting.
TED Talks: Paul Stamets – Six Ways Mushrooms Can Save The World – This is basically his “standard” speech he gives when he does talks. There have probably been additions and improvements to it, but the message hasn’t really changed. This is “Mycelium Running” in about 5 minutes. Watch this to decide whether you want to read that book.
Let’s Grow Mushrooms! by Roger Rabbit – One of the aforementioned Shroomery celebrities. His videos are helpful, but make sure to fact check why you’re doing stuff, because he tends to leave a lot of that out. This is very nuts and bolts demonstrations of how to prepare substrate, how to provide humidity at a low cost, and several different methods of growing for different species of mushrooms.