Japanese Seasoning Soy Sauce Dashi Shoyu

Why This Recipe Works?

A small amount of sugar mellows out the salty soy sauce. By infusing the soy sauce with konbu and katsuobushi, you’re adding umami to the soy sauce along with the marvelous flavor of dashi. Bringing the soy sauce to a boil with the other ingredients has the upside of eliminating the naturally occurring alcohol in the soy sauce, but it can also extract some undesirable flavors from the katsuobushi and konbu. It’s kind of like the difference between cold brew vs. hot brewed coffee. That’s why I prefer doing a cold infusion.

Ingredients for Dashi Seasoning Soy Sauce

Soy sauce - Any Japanese soy sauce like Kikkoman will work, but a traditionally brewed soy sauce made from soybeans and wheat will taste best. Katsuobushi - Katsuobushi is skipjack tuna (sometimes translated as bonito) that’s been fileted, cooked, and smoked for several weeks until it’s dry and hard. Higher-grade katsuobushi is then inoculated with Aspergillus glaucus, a type of filamentous fungus, and sun-dried. Like anything, you tend to get what you pay for. Cheaper katsuobushi are sometimes blended with mackerel, includes a lot of bloodline, and they don’t undergo the extra drying and fermentation. More premium katsuobushi, such as honkarebushi, has gone through the drying and fermentation process at least three times, which can take months. Konbu - In the same way that the growing conditions of plants can affect their taste, konbu (also sometimes spelled kombu) is affected by the conditions of the water in which it was grown. Hokkaido in the north of Japan is said to produce the best konbu, but it’s a big island, and different regions produce konbu with wildly different flavor profiles. Rishiri in the north produces konbu that is mild and mellow in flavor and produces clear, delicate broths. This is why it’s used in fancy Japanese cuisine. Hidaka on the southern side of Hokkaido tends to produce softer konbu than in other regions. It doesn’t have a ton of umami, though, which is why it’s used more for eating than making dashi. My personal favorite is konbu from Rausu in the east, which makes dashi with TONS of umami and a bold meaty flavor. If you can’t find konbu, you can substitute flavor enhancers such as yeast extract or monosodium glutamate (MSG). Sugar - This is not necessary, but adding a little sugar to the soy sauce balances out the saltiness of the soy sauce. It also makes the dashi soy sauce easier to use because it eliminates the need to add sugar to the dish.

How to Make Japanese Dashi Soy Sauce

The first thing you want to do is dissolve the sugar in the soy sauce. How much sugar you add is up to you, but the added sweetness mellows out the saltiness of the soy sauce, and you can adjust this to taste. Add the konbu and katsuobushi to the soy sauce and then cover and let the soy sauce infuse for at least twenty-four hours. When the dashi shoyu is done, remove the konbu and set it aside. Strain the mixture through a tea strainer to remove the katsuobushi, and press on the solids to get as much soy sauce out of it as possible. The resulting sauce can be stored in the refrigerator for a few months. To upcycle the spent konbu and katsuobushi, slice it up and stir it into hot rice or use it as a filling for onigiri.