What You Should Know
These edible mushrooms can be easily mistaken for Reishi or other types of medicinal mushrooms, but they can be distinguished by their texture, which is very soft and rubbery.
They grow from dead wood, are reddish on top, and the edges and undersides are white but bruise brown. The flesh is white but gets darker with age, and they have a white spore print.
Ischnoderma resinosum has a very meaty, beef-like flavor, especially if you let them caramelize in some oil or butter.
The flesh of young specimens is soft and juicy at first. The mature fungus is very tough and leathery.
Other names: Late Fall Polypore, Resinous Polypore, Benzoin Bracket, Smolokorka buková (Czech Republic), Løv-tjæreporesvamp (Danish), Polypore fuligineux (French), Laubholzharzporling (German), Gyantás kérgestapló (Hungarian), Sørlig tjærekjuke (Norwegian), Smolucha bukowa (Polish), Ишнодерма смолистая/смолисто-пахучая/Трутовик смолистый (Russian), Smolokôrovka buková (Slovak), Sydlig sotticka (Swedish).
Ischnoderma resinosum Mushroom Identification
Saprobic on the deadwood of hardwoods; annual; causing a white rot that separates the annual rings in the wood and often smells of anise; appearing on recently fallen wood and on wood that has been down for several years, but not typically on well-rotted wood; growing alone, gregariously, or in overlapping clusters; usually appearing in fall; widely distributed in North America but more common in the Midwest and the eastern United States.
Usually presenting a well-developed cap, but sometimes appearing effused-reflexed or even resupinate.
5–19 cm across; 3–9 cm deep; irregularly bracket-shaped, kidney-shaped, or nearly semicircular; broadly convex; when young quite thick and fleshy, with a finely velvety surface with zones of pinkish brown and brown, and a thick whitish margin; in maturity dark brown, sometimes with zones of blackish brown, fairly bald, dry, and tough.
When young whitish, soft, promptly bruising brown; in maturity pale brown and hard; with 4–6 angular or round pores per mm; tubes 2–8 mm deep.
Whitish to dull pinkish-brown and soft at first; darkening to brown and becoming tougher with maturity.
Spore Print: White.
Ischnoderma resinosum Bioactive Compounds
A considerable amount of work has been done to elucidate the properties of the lectin from I. resinosum. The lectin (a dimer of two identical 16 kDa subunits) is inhibited by the monosaccharide β-galactoside, and to a lesser extent by fucose and l-arabinose (Kawagishi and Mizuno, 1988). Later chemical modification and NMR studies showed that a tyrosine residue is in the carbohydrate-binding site of the lectin (Kawagishi and Mori, 1991).
Ischnoderma resinosum Medicinal Properties
Polysaccharides extracted from the mycelial culture of I. resinosum and administered intraperitoneally into white mice at a dosage of 300 mg/kg inhibited the growth of Sarcoma 180 and Ehrlich solid cancers by 70% and 80%, respectively (Ohtsuka et al., 1973).
Recipe: Herb Marinated Resin Polypore
Yield: about 1 pint
1 lb Ischnoderma resinous, very young and tender pieces only
1/3 cup canola oil
1/4 cup white wine vinegar
1 clove garlic
2 teaspoon fresh rosemary, minced
1 tablespoon thyme, dry
1 tablespoon fresh mugwort leaf, minced (substitute with sage if needed)
4 ea wild bayberry leaves (substitute with a bay leaf if needed)
2 tablespoon kosher salt
1 tablespoon sugar
How to cook
Cut mushrooms into 1/4 inch strips and lightly oil. Season with salt and roast for 30-40 minutes at 375F or until mushrooms are browned and slightly crispy. Stir several times during the cooking process, and don’t overload the pan. You want a little space between mushroom pieces.
Meanwhile, mince garlic and mix with white wine vinegar. Allow garlic to marinate for 30 minutes, then whisk in all other ingredients.
When mushrooms are thoroughly cooked (they will be firm and browned), mix while still warm with the marinade.
Allow to cool to room temperature, then pack into a glass jar and refrigerate. Will keep for several weeks under refrigeration.
Recipe: Ischnoderma resinosum Broth
4 cups chopped cleaned ischnoderma mushrooms, roughly 1 inch or smaller pieces
1 fresh bay leaf
a few sprigs of fresh thyme
1 garlic clove whole
1/4 of one small onion skin on
A couple slices of carrot
8 cups filtered water
Kosher salt to taste
1 tablespoon flavorless oil
How to cook
Sweat the garlic carrot and onion in the oil, add the ischnoderma, and sweat for 2 minutes more. Add the water and bouquet and bring the mixture to a simmer, then turn the heat down to low, cover, and cook for 1 hour.
Strain the stock, then cool, transfer to a labeled, dated container and refrigerate until needed. The stock will keep for at least a week.
Recipe: Ischnoderma Mushroom Conserve
3 lbs small young Ischnoderma resinosum, tender ends only, cleaned and rinsed if needed.
3 large cloves of garlic sliced thin
1/4 cup flavorless oil for sauteeing such as grapeseed or canola
1/4 cup flavorful oil such as extra virgin olive oil, virgin sunflower oil, or a tasty nut-based oil, such as hazelnut
Roughly 1/2 tablespoon of kosher salt
1 qts water or vegetable stock
1/4 cup champagne vinegar or white vinegar.
Large sprig of a hard herb like thyme, or rosemary. (You could also finely chop some of either and add it too, which will give it a stronger flavor.)
2 fresh bay leaves
Tiny pinch of cayenne or red pepper flakes
How to cook
In a wide pan with high sides, or even a soup pot, gently heat the oil and the sliced garlic until the garlic begins to turn golden.
Add the mushrooms, salt and herbs, and allow the mushrooms to give up their juice and stop the garlic from getting too brown. Stir the mushrooms to coat them with the garlic, herbs and oil, and season them with a pinch of the salt.
Continue mushrooms until most of their liquid has evaporated, about 10 minutes, then remove and discard the herbs. Add the court bouillon or water.
Add the vinegar and flavored oil of your choice. Simmer the mixture for a few minutes, then taste the liquid, and adjust with salt if needed.
Finally, put the conserve into a container and refrigerate. If you will be keeping the conserve for more than a few weeks, make sure to put plastic wrap on top of the conserve to keep the mushrooms under the liquid, to ward off bacteria. Under the liquid though they will keep for a few months. You could also freeze the mushrooms in a container or freezer bag, with their liquid.
Recipe: Ischnoderma resinosum Jerky
1 lb Ischnoderma resinosum (resinous polypore) soft parts
½ cup Water
½ cup Soy Sauce
2 tbsp Worcestershire Sauce
1 tsp Onion Powder
1 tsp Garlic Powder
½ tbsp Black Pepper
1 pinch Cayenne Pepper
How to cook
Slice the Ischnoderma resinosum into strips and mix in the marinade for half an hour.
Place mushrooms and marinade in a saucepan and bring to a boil. Boil for 5 minutes then turn down to a simmer and simmer for 5 minutes.
Strain the mushroom from the marinade and place in a dehydrator at 120-130°F for 6-12 hours, until dried and leathery. The time will vary based on the thickness and sizes of the pieces, so check it often.
Store in an airtight jar or vacuum pack.
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