Seasoning Part 3

They say that dashi (stock) is the key to Japanese cuisine. It is a stock made by extracting goodness and flavor from kombu seaweed, dried bonito fish, small dried fish, dried shiitake mushrooms or the like. Dashi brings out the taste of the ingredients and is at the heart of the light flavor of Japanese food. These pages give a taste of two of the most important stock bases, kombu seaweed and bonito fish.

When heated in water, this variety of kombu seaweed, ma-kombu, makes a fine, light, clear stock ideal for suimono soup and other recipes calling for a see-through liquid. Kombu has a delectable flavor all its own and is used mainly to make a broth for clear soups or simmered dishes. The seaweed is harvested along the coast of Hokkaido and the Sanriku district of Tohoku (northern Honshu), then dried, often in the sun. The most common way to make kombu dashi is to cut the kombu into convenient lengths, place it in water in a pot, heat until the water is about to boil, then take it out right away. The wholesaler Fushitaka in Tokyo's Tsukiji Market caters to professional chefs who want high-quality kombu, bonito and other marine dashi products with an authentic, traditional flavor. Fushitaka also reaches out to a wider eating public, selling over the Internet as well. The company president, Nakano Katsuhiko, says “The flavor you get from kombu depends on where it comes from. But all production centers have one thing in common—they are near mountains. You see, kombu needs nutrients washed from a rich humus of decayed deciduous tree leaves. Rainwater washes those nutrients into streams, then out to the sea and the waiting seaweed.”

Above Left: Rausu-kombu is grouped among the oni-kombu type of seaweed. It grows to almost 3 meters long, 25 cm wide. Above Right: Kombu harvested offshore is brought by boat and unloaded on a beach to be sun-dried. Rausu-kombu is quite thick, so it is dried for two or three days.

Top: Blocks of authentic hon-bushi bonito, with the desired coating of mold. The fish is preserved through drying and a fermentation process that cleverly uses microorganisms. Above: Flakes of hon-bushi. The other common base for dashi is dried bonito fish (katsuo-bushi). When you see it you might not believe it is seafood, and this is even harder to believe when you bang two pieces together—they make a clear, high-pitched sound like wooden clappers. Katsuo-bushi is known as the world's hardest food. To make the dashi, first shave off thin flakes with a plane specially made for the job. Drop the shavings in boiling water, turn off the heat right away, let the flakes sit in the water for a while, and then remove them. Or you could drop them in the water just before it boils, and take them out as soon as it does. In either case, the result is a stock called ichi-ban dashi (“number-one stock”). This dashi is great for clear soups. The wet shavings can be reheated in water to extract more nutrients and flavor. This ni-ban dashi (“number-two stock”) is used for stews, miso soup and many other dishes. Chefs prefer to shave off flakes just before using them, but today it is common to buy packaged shavings. The wholesaler Nakano frowns on the easy way: “To get the best taste and fragrance you should shave off the flakes yourself from a bonito block. And the bonito should be prepared properly. That's how to get the authentic taste.” Nakano Katsuhiko's wholesale business is called Fushitaka. His outlet in the Tsukiji Market in Tokyo has a nice, freshly shaven katsuo-bushi fragrance. Japanese-language website: http://www.fushitaka.com Nakano's demand for authenticity is met by the katsuo-bushi maker Kubo Norihide in Makurazaki, Kagoshima Prefecture. The city produces more katsuo-bushi than anywhere else in Japan. Kubo's company has about 10 employees, and they are on the job soon after 6 a.m. The first step is to clean the fish and cut it into large pieces. The pieces are arranged neatly in sieves, then lowered into water that is kept at the right temperature—about 90°C—to prevent the fish from developing cracks. After simmering for some time, the fish comes out of the water, any remaining bones are removed, and the pieces are trimmed to form blocks. Next, the blocks are smoked over a smoldering wood fire, allowed to cool at air temperature, then smoked and cooled again several more times. At this stage the product is called ara-bushi. Most ara-bushi is flaked, packaged and sold as ready-to-use flakes, but to make authentic dashi a few more steps are needed. The ara-bushi should be dried in the sun, the natural tars shaved off the surface, and the blocks reshaped nicely. At this stage the blocks are called hadaka-bushi. Now it is time to cure the blocks with a mold. The dried hadaka-bushi is placed in a room with temperature and humidity controls until aspergillus mold develops on it. Next comes another bout of sun drying. Then the mold is scraped off, the fish goes back into the curing room, and then it is sun-dried again. This process is repeated about four times. The final result is authentic hon-bushi. The smoked bonito fillets, with their coating of mold, are dried in the sun. The sun and mold reduce the water content and enhance the flavor. The mold draws moisture slowly but surely from the fish, giving it the dry, hard finish it is famous for. The mold also breaks down fatty substances in the fish and builds up amino acids to give the final product extra flavor. This hon-bushi manufacturing process is complicated and repetitive, and takes about six months. For someone who puts productivity first the process makes little financial sense. But Kubo would disagree: “They sell cheap katsuo-bushi, but we would rather keep making it the traditional way—after all, the real thing tastes better.”

Above right: Freshly caught bonito fish are filleted. Knives are used to cut out and remove the blood-colored flesh, and this leaves upper and lower fillets to work with. Top: The fish has been simmered in hot water, and now it is being thoroughly smoked. The pieces will be cooled and then smoked again a few more times. The temperature and timing will determine the final taste and flavor. Above left: Kubo Norihide says there are about 70 katsuo-bushi makers in his city, Makurazaki, and about 20 of them still make authentic hon-bushi.