Dashi - the treasure
Water 'source' of Osaka flavor
How can we talk about the food culture of Osaka without knowing about the "dashi culture"? The most important ingredient for making dashi is water. Fortunately, the water in Osaka is soft water which has sweetness and the capability of educing savory from ingredients. And because of the soft water, konbu became an important member of the flavors of Osaka. The soft water allows us to benefit from the konbu for its glutamic acid and other savory features which makes the soup stock filled with aroma. When the glutamic acid combines with hard water, the soup becomes bitter and not appropriate for soup stock. It is said that konbu soup stock was not popular in the Kanto area because many water sources supplied hard water. In fact, it is a rare situation even if you compare with other places around the world to be able to enjoy food made from plant-derived soup stock. Even French and Chinese cuisines use animal or fish based flavors. Although they have recipes that add vegetables, it is for adding a nice aroma. It is a unique feature of Osaka food to have konbu soup stock as the basis of their dishes.
A treasure box of ingredients
It's not just konbu that makes the flavor of Osaka special. After all, it is not called 'Tenka no daidokoro (the country's kitchen)' for nothing. The combination of konbu with bonito flakes from Wakayama, Kyushu and Shikoku and niboshi (dried sardine) from the Seto Inland Sea are fabulous. Of course each ingredient alone can make good soup stock but when they are combined with konbu soup, it deepens the flavor. It is a masterpiece made from the combination of glutamic sodium of konbu and inosinic acid from the bonito flakes and niboshi.
The history of katsuo-bushi (bonito flakes) go all the way back to the 4th to 5th Century during the early Yamato dynasty. It is believed that in those days "Hoshi-gatsuo (dried bonito)" and "Katsuo no Irori (bonito soup)" was eaten. During the Muromachi Period (1336 - 1573) bonito was placed in a basket and hung over the irori fireplace while food was cooked beneath it. Eventually the bonito was smoke-dried from the heat and smoke from beneath it. In the Kishyu area "Baikan-goya (small house for smoke-drying bonito)" were built and it became popular among the big merchants of Sakai and the upper class society of Kyoto to be used for making soups. Later, people in Shikoku and Kyushu learned the skill from Kishyu and made their own products that were sold to Osaka.
For instance the dashi for Udon. "Mimyu", a famous "Udon-suki" restaurant uses Souda-bushi bonito flakes from Tosa and Yakushima and Rishiri-konbu from Hokkaido to make their soup stock. The reason why they use Souda-bushi bonito flakes is for the flavor, color, aroma and deep richness. The flavor of konbu alone is too modest, and katsuo-bushi alone lacks deepness. So the combination of the two is necessary. Along with the two, usukuchi soy sauce is added. They believe that the flavor changes and looses its nice aroma if the soup is cooked and kept for a long time. That is why they don't keep soup stock for a long time. The savory golden-colored dashi, home-made udon noodles, fresh vegetables, clams, shrimp, anago (conger) and other ingredients are cooked together to make Udon-suki. It is like jewelry of excellent ingredients in a box of golden soup.
Another popular dish is iwashi (sardine). It can be fished in the sea around Osaka; 6,000 tons of Katakuchi-iwashi (anchoa) and 100 tons of sardines per year. Sardines loose their freshness quickly so as soon as they are brought to the port, the traders go around town selling them. They call out "Watch out! Here come sardines that are fresh enough to bite your fingers". The large amount of Katakuchi-iwashi that were caught in Seto Inland Seas and other nearby waters where boiled in salt water for preservation, then dried in the sun to make niboshi that was used to make soup. The merchants of Osaka bought them from the fishermen by the Seto Inland Sea at a cheap price. It became popular among the general public for its superb taste at a low cost.
*Take a break - Usukuchi Soy Sauce
The flavor of dashi is known to be light in Osaka and the whole Kansai area. It is because this area uses Usukuchi Soy Sauce. This typical soy sauce has a light color and has 18 to 19% salt content; higher than that of Koikuchi Soy Sauce which has 16 to 18% of salt content. Especially Usukuchi Soy Sauce is used in Osaka and Kyoto. The light color doesn't interfere with the original color of the ingredients, and has a great balance in flavor. Usukuchi Soy Sauce was first made in Tatsuno-shi, Hyogo in 1666. The soy sauce made in Tatsuno-shi is used for Shoujin-ryouri (vegetarian meal) and Kaiseki-ryouri (light meal served before a tea ceremony) in Kyoto and Osaka and has become an ordinary ingredient used for cooking.
