Kombu and skipjack flakes

The basic element of Osaka-style flavor is a blend of kombu (dried kelp) and skipjack flakes.Kombu, which is produced in Hokkaido, was transported to Osaka over the Japan Sea via the kitamaebune shipping route, which was begun during the Edo era. Goods ferried to Osaka included seafood such as kombu and herring, while return ships were loaded with items including rice, salt, saké and used clothing. In addition to reaping handsome profits, merchants were also able to cultivate a two-way cultural trade between the two regions. The emergence of dashi—a quintessential element of Japanese cuisine—from Hokkaido kombu may be described as a superb product of this history.Rishiri kombu (Rishiri island in Hokkaido) found popularity in Kyoto. Meanwhile, makombu (“true” kelp) produced in southern Hokkaido was shipped directly in large quantities to Osaka, where its rich umami wasfavored by the local palate over its Rishiri counterpart.Makombu was later paired with flakes from dried skipjack fished in what are now Wakayama, Kochi and Kagoshima prefectures to create awasedashi blended cooking stock. The glutamine acid from the kombu and the inosinic acid from the skipjack flakes worked together synergistically to coax out a beautifully strong umami flavor.High-end restaurants proudly serve their own unique versions of ichiban dashi (“first cooking stock”), which has been crafted from the highest-quality makombu kelp and skipjack flakes.The remains of the strained broth, are also carefully utilized by finely chopping the kombu and incorporating it with the skipjack flakes, which may then be used to create furikake (a seasoned powder for sprinkling) by adding a salty-sweet seasoning, or a dish known as tsukudani by boiling the mixture together with soy sauce and mirin (a sweet cooking saké).Osaka has the highest kombu consumption in all of Japan. The popularity of this northern item in Osaka—to the extent that it even became known there as a local specialty product—owes to the processing technology that exists in the region. Knife technology in Sakai facilitated the processing of tororo kombu (grated kelp) and oboro kombu(dried kelp in thin, wide strips); while the technology for shoyu in Wakayama prefecture resulted in the creation of salted kombu. In addition to dashi, numerous additional products continue to be processed from kombu today.