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Is it right to grow oyster mushrooms on cotton-seed & use Formalin + water for pasteurization? Answered

Hello Rocketsurgery!
It's my first time growing oyster mushrooms. I am using "cotton-seed" as a growing medium since it's the material I can find in my area. And for pasteurization, I add "Formalin" into water and soak it for 2:30- 3:00 hrs. This is how the instructors in my area told me.  Do you think I'm doing  it the right way OR  Do you have any suggestion on how I  should grow it better???


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3 years ago

OK ..... You want to contact rocketsurgery go to his home page and send him a direct message because he probably does not follow Answers.

If this works for you then you could click on the Best-Answer...

Jack A Lopez
Jack A Lopez

3 years ago

I am guessing that you put the word, "Formalin", in quotes to just to put some emphasis on it, rather than to use the word in a non-literal sense.

I mean, you are not writing about metaphorical formalin, or sarcastic formalin. I am guessing that you are referring to a real chemical mixture, a solution of formaldehyde in water, maybe with some methanol mixed in too. The wiki article linked below has more info. Just use control-f, to jump to the part where the word, "formalin", is mentioned.


Anyway, that stuff is really toxic, also carcinogenic. So to me that seems like a bad idea to include it in the preparation of something that you're going to eat.

Although maybe it is safe at really low concentrations, the way aqueous sodium hypochlorite (also called chlorine bleach) is used in diluted form for sterilizing cutting boards, and swimming pools, and sometimes for sterilizing drinking water.

But carcinogenic? That seems bad. Unless you already have a lot of carcinogen exposure in your life, like a job working with radioactive waste, and smoking cigarettes while you do it. Ha!

I think the usual way to homebrew way to sterilize a growth medium, is using a pressure cooker,


I mean that's for batches of material smaller than the volume of the pressure cooker, like 6 quarts, 8 quarts. A quart is about the same size as a liter.

It kind of looks like this guy, Rocketsurgery, is making rather large batches, in his instructable on this topic, here,


And his method for sterilizing the medium is ambient pressure steam, created by cooking bags of growth medium in a big steel barrel with water in the bottom to make the steam. That is in shown in Step 3, of the previously linked 'ible.

Does instructables have other 'ibles on mycoculture (i.e. growing mushrooms or other fungus)?
I guess there are a few here, according to this let's make search for "grow mushrooms"

Moreover, I know there are other forums out there devoted to nothing but mycology and mycoculture, like shroomery.org, although they seem to be mostly interested in psychoactive fungus.

Maybe your specific question about formalin and growing oyster mushrooms could be answered by asking a search engine about, "formalin and growing oyster mushrooms"?


Yeah. Looks like people are doing that. Maybe you knew that already.

Well, I dunno. I guess I'm back to what I said earlier. My intuition says a pressure cooker, or ambient pressure steam, would be safer, because water and heat are not inherently poisonous, not carcinogenic.


3 years ago

Well, I would never use formaldehyde on or with anything I intent to eat.
The stuff is just too toxic for my liking.
If you need to sterilise things then there are plenty of options that won't including harming your health.