Preparing Shiitake: Cleaning Fresh Ones, Soaking Dried Ones

Fresh or dried: what the difference is

Fresh and dried shiitake are the same mushroom but taste different. Fresh shiitake are mild, slightly earthy and juicy. Drying concentrates the aroma: dried shiitake taste strongly of umami, almost smoky, and give a broth more depth than fresh ones.

For quick stir-fries, ramen toppings and vegetable pans, use fresh mushrooms. For broths, braises, fillings and rice with mushrooms, reach for dried. Many Chinese and Japanese recipes assume dried shiitake, even when the ingredient list does not say so explicitly.

With dried shiitake you see two types at the Asian grocery store. Thick, domed caps with a cracked, pale surface are called donko in Japanese and huagu (flower mushroom) in Chinese. They stay meaty after soaking and suit braising and serving whole. Flat, wide-open caps (koshin) soak faster and work well in broths or sliced into stir-fries.

Preparing fresh shiitake

1. Clean: Rub off dirt and bits of growing medium with a brush or dry paper towel. Do not wash the mushrooms under running water, because they soak it up and then will not brown.
2. Remove the stems: The stems of fresh shiitake are tough and fibrous. Twist them out or cut them off right under the cap. Do not throw them away, but collect them in a freezer bag for the next stock.
3. Cut: Leave small caps whole or halve them, and slice large ones. For ramen and skewers you can score a cross into the top, which looks nice and helps the marinade soak in.
4. Cook: Heat the pan or wok well, use little oil, lay the mushrooms in one layer and turn them only after two to three minutes. Salt and soy sauce go in only at the end, or they draw out water and the mushrooms boil instead of fry.

Do not eat shiitake raw. In some people, raw or barely cooked shiitake cause an itchy, streaky skin rash, so-called shiitake dermatitis. So always cook the mushrooms all the way through.

Soaking dried shiitake

Soaking decides flavor and texture. Cold water and time give the best result.

1. Rinse: Briefly rinse the mushrooms under cold water to remove dust.
2. Soak: Put them in a bowl and cover with cold water. A small plate on top keeps them under, because dry mushrooms float. Let them steep covered in the fridge for 8 to 12 hours, thick donko caps up to a day.
3. Check: Press the middle of the cap. If it is soft with no hard core, the mushrooms are ready.
4. Squeeze: Take the mushrooms out and squeeze them lightly by hand. Catch the liquid in the bowl.
5. Cut off the stems: Even soaked, the stems stay tough. Cut them off and add them to a stock.
6. Filter the soaking liquid: Pour it through a fine sieve or a coffee filter. Grit often settles at the bottom, and you discard the rest.

If you are short on time, use lukewarm water and a pinch of sugar. Thin caps are then soft after about 30 minutes, and thick ones take longer. The aroma ends up a bit flatter than with the cold method, but it is enough for a stir-fry. Boiling water makes the mushrooms rubbery on the outside before the middle softens.

The filtered soaking liquid is a ready-made vegan stock. Use it for soups, sauces or for cooking rice. This shiitake dashi shows how to build a stock from it on purpose. You will find more about dashi and its basic ingredients under dashi and dashi powder.

Using shiitake in recipes

• Soups and broths: Soaked mushrooms and their liquid give miso soup and ramen depth, for example in the miso soup with shiitake and tofu or in shio ramen with mushrooms.
• Rice: In xiang gu fan, mushrooms and rice cook together, and the soaking liquid replaces part of the cooking water.
• Pickled and braised: Braise dried donko caps in soy sauce, sugar and mirin until they shine. You will find a variation in the pickled shiitake mushrooms.
• Fillings: For dumplings and spring rolls, finely chop soaked mushrooms. They add bite and flavor.

Two to three dried caps per person are enough for a broth. Dried shiitake take up many times their weight in water when soaking, so buy a small pack and use it up.

Common mistakes

• Washing fresh mushrooms and frying them right away: They spatter, turn gray and stay soft.
• Eating the stems: Even cooked long, they stay woody. In a stock they give up flavor, on the plate they get in the way.
• Soaking too briefly: A hard core in the middle of the cap does not give way during cooking.
• Pouring away the soaking liquid: That loses most of the aroma.
• Using the soaking liquid unfiltered: Grit crunches in the soup.
• Too much soy sauce: Dried shiitake bring their own umami. Season at the end.

Buying and storage

Many supermarkets carry fresh shiitake in the produce section, including locally grown ones. Look for firm, dry caps with a rolled edge and pale gills. You can buy dried shiitake at Asian grocery stores in many sizes and grades, and also in well-stocked supermarkets and online. Whole caps are more versatile than pre-sliced pieces.

Store fresh mushrooms in a paper bag in the crisper drawer. They keep there for a few days, while in plastic they turn slimy fast. Dried shiitake keep well for many months stored airtight, dry and dark. Use soaked mushrooms within one to two days or freeze them, and the soaking liquid too, for example in portions in an ice cube tray.