Kombu Onigiri (Kelp "Tsukudani" Rice Ball)
Have you ever wondered if you can use your leftover kombu after making dashi? Well, the answer is you can! You won't believe how delicious kombu itself can be until you try this recipe. This umami-packed simmered kelp called "Tsukudani" is one of Japan's most popular onigiri fillings!
- Prep time
- 10 min
- Cook time
- 40 min
- Yield
- 6 servings
- Difficulty
- MEDIUM
Ingredients
Quantities are shown as originally provided.
- 50 g rehydrated kombu ((kelp))
- 500 ml water
- 2 tbsp sake
- 1 tsp rice vinegar
- 1 tbsp light brown sugar
- 1 tbsp mirin
- 2 tbsp Japanese soy sauce (koikuchi shoyu)
- ½ tbsp toasted white sesame seeds
- 600 g cooked Japanese short-grain rice
- 2 tsp salt
- 6 pieces roasted seaweed for sushi (nori) (cut to rice ball size, 1 sheet of sushi nori will be enough for approx 4 onigiri)
Instructions
- 1
Before starting, make sure your kombu is already rehydrated. It needs to soak for at least 1 hour before making tsukudani, and the leftover liquid can be used as kombu dashi.
- 2
You can cook the rice while the tsukudani is simmering. Use Japanese short grain white rice or sushi rice. The rice needs to be sticky so that it holds it shape. Use a rice cooker or check out my how to cook Japanese rice on the stove recipe.
- 3
Cut 50 g rehydrated kombu into thin strips. (About 3mm or 1/10 inch thick)
- 4
Add the sliced kombu to a pan with 500 ml water, 2 tbsp sake and 1 tsp rice vinegar. Bring to a rolling boil over a medium heat, then lower the heat and simmer until the water has reduced to a little less than half. This should take approximately 20 minutes.
- 5
Add 1 tbsp light brown sugar, 1 tbsp mirin and 2 tbsp Japanese soy sauce (koikuchi shoyu). Mix well and increase the heat back to medium.
- 6
Continue to boil until the liquid is completely reduced, mix often to prevent burning. Once thick, sticky and dark, sprinkle in ½ tbsp toasted white sesame seeds and mix well.
- 7
Sprinkle salt over your rice ball mold (or slightly dampened hands) and shape your rice. Place 1-2 tsp of the kombu tsukudani in the center and encase.
- 8
For more details on how to shape onigiri by hand, check out my 3 ways to shape perfect onigiri post.
- 9
Wrap the onigiri with a sheet of nori and enjoy! You can also place the kombu tsukudani on top of the rice ball for decoration.