Fermented mushrooms make a great salad addition or side condiment. You can balance any sourness by adding some maple syrup or seasoned rice vinegar.

Fermenting mushrooms can be a bit controversial. If you do some research, you’ll find recipes for raw, dehydrated, and cooked mushrooms. Some health experts such as Dr. Andrew Weil suggest that mushrooms are indigestible if eaten raw because of their tough cell walls and advise people to cook them to release their nutrients. We also need to be aware that some mushrooms can be toxic if not cooked properly.

As a wildcrafter, the rule I learned from my elders is to avoid eating wild mushrooms raw, and I follow that rule for fermentation. I usually slice the mushrooms, but if they are small enough, like baby bella or shimeji, I use them whole.

So far I have fermented shiitake, baby bella, shimeji, portobello, enoki, button, and oyster mushrooms (commercial and foraged). Before using any wild mushrooms, exercise caution and do some research on edibility and cooking time. Because the mushrooms are cooked, I assume there are no live bacteria and I use a lacto bacteria starter in my ferments.

Some Russian recipes ask you to boil the mushrooms, cool the solution, then add a brine of water, salt, and spices with the addition of a leaf on top to keep everything under the brine. Whey is usually used as a starter, and it’s common to add sugar to kick the fermentation into high gear. I haven’t used this method, but it seems valid as long as the mushrooms are properly cooked. I also add maple syrup or another source of sugar in my mushroom ferments.

A Note on Mushrooms

If you use button or cremini mushrooms, purchase “babies” or young ones. You want them small. The larger ones will tend to become too mushy once aged, unless you like that sort of thing; or, they could be used to make a fermented paste.

I like to steam the mushrooms instead of cooking them in a pan; even small ones keep their shape when steamed. There’s nothing complicated about it: Just use a steamer basket or pot, the same one you steam vegetables with. Place your mushrooms in the steamer basket over water and turn the heat to high. Steam, covered, until quite tender, about 10 to 15 minutes for small or delicate mushrooms and up to 20 minutes (baby bella) or more depending on the size. My simple rule is to make sure they are thoroughly cooked. Remove and place the mushrooms in a colander. Let them cool off for 20 minutes, and you’re ready to ferment them.

KIMSHROOM (OR SHROOMCHI)

I’m not sure what to call this, so you can pick the name you prefer. It’s simply mushrooms fermented in brine with chili flakes and garlic, akin to some kimchis, though you may argue that anything that has garlic and chili flakes/powder will have a similar flavor profile. It’s a delicious, tangy, sour, and spicy ferment with regular (baby) button mushrooms, but it also works well with shimeji (beech) or oyster mushrooms.

Ingredients for a 1-quart jar

(946 ml) (around 80 percent full)

Around 14 ounces (397 g) mushrooms

3 tablespoons (22 g) Korean chili flakes (quite mild); you can add some spicy chili powder or flakes as well

½ teaspoon (1.5 g) smoked jalapeño chili powder (optional)

2 teaspoons (11 g) salt

5 garlic cloves, chopped

1 cup (236 ml) water

1 teaspoon (2.5 g) freshly grated ginger root

3 tablespoons (44 ml) Culture Starter

2 teaspoons (10 ml) maple syrup (you can also use sugar or honey)

Procedure

1. Steam the mushrooms for 20 minutes, then place them in a colander to cool off for 20 minutes or transfer them to a bowl and add the remaining ingredients. Mix everything thoroughly, then pack it into a quart jar. The jar should end up around 80 percent full. 

2. Use fermentation method 3 (page 28), as for the Fermented (Baby) Cremini Mushrooms. The only difference is that I like this ferment aged.

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