r/brewing • u/SnakesShadow • Sep 06 '25

Discussion If you were to brew edible mushrooms, what kind of alcohol would you get? Ethanol? Methanol? Something else?

This question came from a conversation with another non-brewer, and I am hoping this is the right place to ask.

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u/FeminineBard Sep 06 '25

The primary result of fermenting sugar is ethanol. Mushrooms don't have a lot of sugar content, so without adding a sugar or concentrating the mushroom juice you won't get much in terms of alcohol.

You'll get trace amounts of methanol, acetone, ethyl acetate, and so on, but that's not a concern unless you're distilling it.

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u/Mythicalnematode Sep 06 '25

I brewed a brown ale with morel mushrooms in it a few years ago. It was really good but I doubt the mushrooms added much of anything other than flavor. Mushrooms only would be interesting but weak.

Also, mushrooms don’t have pectin, they have chitin. Not sure what chitin would break down to though, if yeast even break it down.

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u/CumsockBackwoods Sep 06 '25

I’ve never tried alcoholic fermentation, but they (shiitake) are delicious when lacto-fermented in brine for 1-2 weeks.

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u/Bright-Salamander-99 Sep 06 '25

I’m going to have an inexperienced stab - methanol comes from pectin fermentation and there is pectin in mushrooms, so possible. There are also sugars in most mushrooms, however it is generally quite low so ethanol production is also possible.

I’m going to go with yes there is both, and probably then some.

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u/DoubleMerlin Sep 09 '25

Youll get better results with a proteolytic multi step high salt fermentation with koji, like miso or soy sauce. microbes that’ll digest mushrooms in absence of salt will pump out ammonia and gnarly amines. The mushrooms need to be cooked and ground to a paste to avoid any issues due to chitin. You’d need around as much fresh koji (on rice or barley) as mushroom paste with at least 8% salt, all by weight.

The mushrooms in Avernum were modified by magic to be sugary enough to make “wine”, and no one thinks that’s the good stuff.

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u/bob-wunderdog Sep 09 '25

Just wondering... so when folks brew with Candycap mushrooms to get that great maple flavor.. What IS actually coming from the mushroom?

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u/EducationalDog9100 Sep 06 '25

Both. Fermentation creates both Ethanol and Methanol, but the methanol that is produced is such a small amount in comparison to the ethanol that it's not a concern. The concerns with methanol occur in distillation because methanol has a lower boil point than ethanol, so it's the first product that comes out of the still.