n Japanese cooking the stock that is the basis for soups, braises, sauces, and dressings is dashi. It can be made with kombu (dried kelp, sometimes spelled as konbu), hoshi-shiitake (dried mushrooms), katsuobushi (dried bonito flakes), or niboshi (dried anchovies, sometimes called sardines). I have seen references to making dashi with clams (asari or shijimi), dried mackerel flakes (sababushi), or dried young “flying fishes.”W
hat to have ready for making dashi:
bowls or covered plastic containers for soaking dried ingredients
measuring cups for water
deep strainer lined with a
fukin (cotton kitchen cloth, or triple layer of cheese cloth. Wet the cloth and squeeze out the water so it’s damp.)
2 pots large enough for the amount of stock
freezer containers, mostly 1 quart size, but it’s useful to freeze some in 1 and 2 cup sizes and even cubes
Kombu is made from various types of kelp. When harvested and dried naturally, kombu acquires a thin layer of white powder which some believe is extremely flavorful. Kelp has a high concentration of free glutamate, which creates the famous umami, or “fifth taste” in Japanese cuisine.
I can usually find only the dried leaves or fronds, cut into rectangles and sold several sheets per package. I’ve never seen fresh kombu—its shelf life is too short to travel all the way to Michigan! Apparently kombu is sometimes sold frozen.
Some kombu I’ve used has been thick and almost black and comes in long ridged strips; this type is imported from Japan and is expensive. Other kombu is less expensive whether imported from Japan, Korea, or China, and is dark green, with fewer ridges; some is very thin and cheap. Dried kombu, stored in a cool dry place, will keep for a long time. Before using a sheet of kombu, wipe it gently with a damp cloth.
When I first started cooking Japanese food, I’d throw the kombu away after making dashi. But it can be used in hot pots, as a base for steaming fish or poultry, or quickly pickled (tsukemono) to eat as part of a whole meal or snack. Try Cauliflower Tsukemono with Citrus and Kombu or Senmaizuke Turnip and Kombu Tsukemono. When cooking beans, I add a piece of kombu because I read that it helps soften the beans, reduces cooking time, and makes them easier to digest.
♥ two 4-inch squares kombu
♥ 2 quarts water
Soak the kombu in cool water for between 30 minutes to over night. With the longer soak, the water takes on a green color and the kelp softens and expands.
Put the kelp into a pot and add the soaking liquid plus cold water to make 2 quarts. Bring the water and kombu almost to a boil over medium heat. It should take 10 to 15 minutes.
Immediately before the water reaches a boil, remove the kombu. (Save it for preparing “second fish stock” below.) If you boil the kombu, the stock will become bitter and cloudy. Strain the liquid throught the sieve lined with damp cloth. Use immediately, refrigerate, or freeze.
♥ 3 to 4 nice-sized good quality dried shiitake, soaked from 3 hours to overnight until soft. Use a weight to keep the mushrooms below the soaking water. You can make dashi with only dried shiitake, or you can add soaked shiitake to the water with the kombu. Heat just to a boil and strain as above.
Good Household Management Tip: If you are soaking shiitake to prepare another dish, don’t toss out the soaking liquid: freeze it until you are making vegetarian dashi and use it as part of the stock liquid.
Sometimes saké, mirin, and shoyu are added to vegetarian dashi for extra flavoring, and also to any kind of dashi used in braises and sauces.
While often thought of as a vegetable and prepared like one, mushrooms are actually a fungus, a special type of living organism that has no roots, leaves, flowers or seeds. Shiitake are native to China, and have been cultivated there and in Japan for centuries. The Japanese syllable ‘Shii’ refers to the original host tree (perhaps oak or ash). ‘Take’ means the fruit of the mushroom. Shiitake do not grow wild in the US, although they are cultivated on logs inoculated with mycelium, and sometimes the spores will spread into firewood, but yield very few mushrooms.
From Mr. Tess:
“Mushrooms produce spores, minute reproductive structures which are dispersed by air currents.Shiitake colonizes logs by permeating and penetrating the wood with small thread-like hyphae (singular hypha). Collectively hyphae are referred to as mycelium (plural mycelia) which appears as a white cottony mass.
All mycelia in a shiitake colony contain the same genetic material, but the genes are reshuffled during spore production. Thus colonies which start from spores are different from their parent mushroom(s), whereas colonies resulting from the transfer of mycelium are genetically identical to the parent mycelium.”
pg. 4 Shiitake Growers Handbook: the Art and Science of Mushroom Cultivation:
Przybylowicz and Donoghue; Kendall Hunt Publishing, Dubuque, Iowa 1990
These mushrooms are sometimes called the medicinal mushrooms where their healing purpose in China dates back to 100 AD. Studies in animals have found cholesterol-lowering, and virus-inhibiting effects in compounds in shiitake mushrooms. However, clinical studies are needed to determine whether these properties can help people with cancer and other diseases. Extracts of shiitake are sold in the U.S. as dietary supplements, which are not required to meet the approval of the FDA for effectiveness, safety, or purity. The mushrooms are delicious at any rate.
Fresh shiitake are chewier than regular white button mushrooms and have more flavor. Fresh shiitake are good for grilling, stir-frying, deep-frying, and simmering. Cooking time should be short or the mushrooms will loose juice and flavor. Dried shiitake have an even more intense flavor and fragrance. They are chewy texture even after cooking. The water in which they are soaked is flavorful and contains water soluble nutrients. This liquid can be used to prepare a vegetarian basic stock for soups.