Dashi: The Heart of Japanese Cuisine
In layman’s terms, dashi is Japanese stock. In poetic terms, it’s the secret and the heart of Japanese cuisine. For over 1300 years, the umami-rich combination has been used to enhance and harmonize the flavors of Japanese dishes, from delicate kaiseki compositions to robust hot pots and soups. It’s a wildly versatile stock that is just starting to be used in the Western world by savvy chefs who recognize the je ne sais quoi that it can add to a dish, no matter the cuisine.
In traditional Japanese cooking, dashi forms the base of soups and sauces, dresses vegetables, imparts subtle savor to fish…the list goes on. The word most often refers to the combination of a particular seaweed (kombu, a.k.a. kelp), a particular dried fish (katsuobushi, a.k.a. bonito), and water—but that’s not the only version. Shiitake-kombu dashi is used in Buddhist vegetarian cuisine; some dashi is made without kombu, and other is made with small smoked fish instead of bonito. But it’s when kombu and katsuobushi come together that a dashi of superior fragrance and umami is made—a dashi that is said to accentuate the flavor of any savory ingredient it touches.
Its deep, complex taste is the result of relatively little work (on the cook’s part, at least). While Western stocks are made from raw or just-cooked ingredients, dashi starts with highly flavorful, aged ingredients. So, instead of being simmered for long periods of time, they need only be steeped. And like tea leaves, some ingredients can be used again. Leftover bonito shavings can make a second, stronger dashi (called niban, or secondary dashi). Dried shiitakes used to make shiitake stock can be sliced and added to another dish. A last year’s Gourmet Institute, Chef David Chang of Momofuku in New York made a new world dashi by steeping Benton’s smoked bacon in kombu broth as though it was bonito. After straining the broth, he crisped the bacon and incorporated it into the final dish.
It’s said that if 10 chefs prepare dashi, 10 different stocks will be made—and that’s only counting traditional preparations. As much as dashi can be incorporated into myriad dishes to add savory depth, various ingredients (like bacon) can be prepared using the dashi technique. And dashi can be seasoned—Chef Bill Kim of Urban Belly in Chicago adds a bit of mirin, to taste, and Chang seasons his with tare (pronounced ta-day), a reduced mixture of mirin, brown sugar, and dark soy. At Sixteen in Chicago, Frank Brunacci makes a French-Japanese fusion dashi, combining dashi, chicken stock, mirepoix, veal, and Asian aromatics. Purists would be shocked, but the result—poured tableside over a petite portion of nori-crusted hamachi—is a beautifully light, aromatic addition to the dish.
Top Japanese chefs believe that a series of subtle influences shape their dashi, from the type of kombu and katsuobushi used, to the water (preferably soft), the timing, and the weather. Like so many things, it just takes experimentation and bit of practice to make it your own.
Kombu: kelp grown off the northern island of Japan, harvested and dried before use. Drying occurs in a matter of hours, after which the kombu is shaped and shipped. There is a cellar-aged kombu called kuragakoi. Like wine, it’s laid down for anything from one to a few years in a temperature-and humidity-controlled storeroom. The maturation is said to remove the seaweed odor and enhance the levels of umami.
Katsuobushi: bonito that has been simmered, boned, and smoke-dried. Some is then injected with a mold that induces fermentation. The process takes several months, and produces a hard, flavorful block that looks and feels more like a piece of wood than a fillet of fish. The blocks are shaved and it is used in flake form. There are two main types of katsuobushi: arabushi (no mold added), which has a lighter umami taste, and karebushi (mold added), which is harder and more flavorful.
Temperature: if heating kombu in water, the kombu should be removed when bubbles appear in the water, around 140-150°F/60-65°C. If heated to a higher point, the kombu will begin to flavor the water too strongly. A similar temperature, 140-160°F/60-70°C, is ideal for adding the bonito flakes.
Skimming: the scum that rises after the addition of the bonito should be skimmed and discarded. It is composed of oxidized lipids, which have bitter notes to their taste and can add unpleasant astringency to the dashi.
Straining: dashi should be strained and cooled immediately to prevent the evaporation of the elements which give it its good smell.
Storing: dashi can be stored in the fridge or frozen. Refrigerated dashi should be used within two days; dashi frozen in an airtight container should be used within 3 months.