Ischnoderma resinosum is a great all-around mushroom, and I managed to snag a few at the end of the season before it got too cold. I'd made a note to ferment some up to see how I liked them.
Sure, There's plenty of mushrooms you could ferment like this, but some are better than others. Kimchi to me, means fermenting things with some other strong, spicy, stinky flavors, which means lots of delicately flavored mushrooms (local chanterelles and porcini for example), would probably be a waste fermented with chilis, garlic and ginger, unless you have the desire, and/or a comically large haul and you're running out of ideas. Ischnoderma will happily become a flavor vehicle for funky aromas-their texture is what shines here.
Besides choosing a mushroom with a flavor (or lack of one in the case of say wood ears) there's a few rules to take into account with fermenting wild mushrooms that you won't be cooking before ingesting. Basically, it's good to have some kind of benign, tame mushroom, or one you could eat raw if you want to consume the end product without cooking it. Personally I don't care either way, I just want whatever tastes the best.
Polypores are pretty tame from an edibility perspective, and have shapes that are easy to cut into slices and strips, so they're what I used, but black trumpets would be good too. Cultivated mushrooms, especially strips of portobello, quartered shiitake, or the pleasantly bland wood ear would be good too.
Vacuum Sealed Mushroom Fermentation
Another difference from typical kimchi that I used for peace of mind/ease, and safety, was a vacuum sealer instead of a vessel. Fermenting wild mushrooms is not for amateurs, but vacuum sealing removes air-borne bacteria, the arch-nemesis of ferments, which takes a lot of guesswork out of the equation.
Even if you've never fermented a thing in your life, you, yes you, can safely ferment using a vacuum sealer. It may not look as cool as the currently fashionable, handmade ceramic fermentation vessels someone made while living in a yurt, but it won't fail you.
I still have plenty of crocks and things around made for kraut and the like, but kimchi is stinky. If you have a partner or loved one that doesn't like the exciting game I used to play in college called "find the smell", vacuumed, odorless ferments can be a god sent.
On Safety and Raw Mushrooms
Some people think eating raw wild mushrooms is heresy, and it definitely isn't advisable for some species. 14 day fermented mushrooms are essentially cold pickled, due to the lactic acid created from salty lacto-fermentation, so they're not technically raw, but as no heat has been applied, certain species shouldn't be eaten like that.
You can cook this before fermenting
To be crystal clear, you can absolutely cook your mushrooms before you ferment them, and you can probably get slightly different flavors if you lightly color them. To be clear on another point, in order to ferment mushroom species known to cause issues with some people, such as morels, honey mushrooms, or Leccinum, you must cook them either before or after fermenting.
To precook mushrooms for fermenting, steam them for a few minutes, or sweat them in oil, covered, without browning until completely cooked. You could also cook them after they've fermented, but splattering chili paste can be messy. Cooking the mushrooms in the vacuum bag (sous-vide), although convenient, will not reach proper temperatures some mushrooms need to denature problematic compounds that could give you a tummy-ache.
This is a really good condiment for a bowl of steamed rice, or other bland starches since it's highly seasoned, as it should be. Use wherever you would kimchi.
Wild Mushroom Kimchi, with Ischnoderma resinosum
- Vacuum sealer (optional)
- 7-8 oz 2 heaping cups thinly sliced, tender Ischnoderma resinosum or similar wild mushrooms
- 10 grams 1 Tablespoon finely chopped fresh garlic
- 5 grams 2 teaspoons minced or grated fresh ginger
- 10 grams 2 teaspoons kosher salt
- 20 grams scant ¼ cup mild korean chili flakes (gochugaru)
- 1 Tablespoon white rice flour or finely grind white rice in a coffee grinder
- 80 grams yellow onion ¼ cup chopped
- 12 grams 1 Tablespoon maple syrup
- 2 Tablespoons good fish sauce Red Boat brand is the standard
- Process the salt, fish sauce, garlic, ginger, maple, chili flakes and onion in a food processor until a paste is formed, then taste the paste, and if adjust the heat level if needed. Mix the paste with the mushrooms, then quickly pack into a vacuum bag using the moist setting, seal, label and date.
- If you don't want to use a vacuum bag, or a sealer is unavailable, you can press everything down in a mason jar and putting a weight on top of it, making sure to keep everything underneath a layer of liquid. If you're vacuum sealer has difficulty sealing liquids, put the mixture in a ziploc bag, then put the zip loc in a vacuum bag and seal.
- Put the mixture in a cool, dark place for two weeks inside of another container that can catch liquid if the bag leaks, which is rare, but possible.
- After two weeks, slice open the bag like a Christmas present and eat hot or cool with some steamed rice, eggs, or other bland foods that can welcome aggressive flavors.
- The kimchi will last for at least a month and probably longer in the fridge, stored in a container with a tight fitting lid, such as a mason jar, etc.
- For you fermenters out there, the proportions below start with about 5% salt by weight of mushrooms, but you could sure cut it down to 3% and add some extra soy or fish sauce for funk. Typical kimchi recipes start with a brine of 7%, and add extra salt by way of fish sauce from there, but I wanted their natural water to stay in the mix. Either way will be fine.
- The recipe here is basic, if you want, add some garnishes like scallions or spring onions, shredded carrot, etc.
- Look for Korean chili flakes at your local Asian market or online. Look for a brand like this one.
- I add rice flour to bind the liquids and make it saucy, if you grind your own rice flour, you might want to add a tablespoon or two of water and simmer the mushroom kimchi after it ferments to make sure there aren't hard rice pieces.
- I use medium Korean chili flakes (gochugaru) but they come in mild, medium or hot, if you want a nuclear hot kimchi, purchase accordingly.