What Rausu kombu is: how to choose the dashi kombu called the king of kombu

Go to buy kombu for dashi and you are met with names, "Rausu," "Rishiri," "ma-kombu," with no obvious way to choose. They look like the same kombu, but the dashi they give is quite different.

The one spoken of as the "king of kombu" is Rausu kombu, grown off Rausu in Hokkaido. How does it differ from the rest, and how should you use it? As a way into choosing dashi kombu, let us look at this one sheet.

Thick kombu raised by the rough seas of Shiretoko

Rausu kombu grows in the waters off the town of Rausu, on the eastern shore of Shiretoko, a World Natural Heritage site. Tossed by nutrient-rich rough waves, it comes up thick and firm.

Rausu kombu ranks as a top-grade product alongside ma-kombu and Rishiri kombu only because of that fortunate setting. The strength of the sea it comes from becomes the strength of the dashi.

Its character: a rich "golden dashi"

What Rausu kombu has to offer is a dashi that is high in aroma and rich in taste. What you draw is a clear, golden liquid. Body and sweetness stand out, and the savor is refined and forceful at once.

Dashi kombu changes its expression with its growing region. Rishiri kombu has long been the choice when you want a clean, clear dashi, ma-kombu when you want something with no quirks that works anywhere. Among them, Rausu kombu is the one to lean on in dishes that need real depth and body. That presence is why ryotei kitchens favor it.

Rausu kombu: from first-run dashi to tsukudani

Handle a single sheet with care and nothing about Rausu kombu goes to waste. Start with a first-run dashi. Use it in hot pots, clear soups, or rice cooked with other ingredients, and a rich savor rises up like something from a ryotei.

The kombu left after drawing the dashi can be sliced and simmered into tsukudani. Using the gift of the northern sea down to the last piece: that is how you get along with kombu.

Drawing the dashi, and choosing the kombu

• Soak in water for at least 30 minutes, then heat slowly over a low flame
• Lift it out just before the water boils and off-notes stay away
• Reach for Rausu when a dish needs a rich dashi, Rishiri when you want it clean
• Slice the spent kombu and simmer it into tsukudani

Swap your usual dashi for Rausu kombu and the depth of your soups changes. Take one sip of the first-run dashi and see how rich it runs.

Frequently asked questions

How does Rausu kombu differ from other kombu?

Rausu kombu is a top-grade dashi kombu spoken of as the "king of kombu" alongside ma-kombu and Rishiri kombu. It grows thick in the rough waters off Rausu, on the eastern shore of Shiretoko, a World Natural Heritage site. It yields a clear, golden dashi, and is known for a rich savor in which body and sweetness stand out.

How should I choose dashi kombu by growing region?

Kombu takes on a different character depending on where it grows. Rausu kombu is at its best in a rich golden dashi with real body. If you prefer a clean, clear dashi, look to Rishiri kombu; for something refined and all-purpose, ma-kombu. Choose to suit the dish and your own taste.

Any tips for drawing a good dashi from Rausu kombu?

Soak the kombu in water for at least 30 minutes, then heat it slowly over a low flame. Lifting it out just before the water boils is the trick for keeping off-notes out. Rushing it to a boil tends to cost you the aroma, so take your time and draw the savor out slowly.