What do you do with the leftover kombu from making Japanese soup stock (dashi)? Make Kombu Tsukudani (Simmered Kombu) cooked in a sweet and savory sauce. It’s a great dish to accompany your ordinary steamed rice!
Once you start making Japanese dishes, you will realize you are left with used kombu from making homemade dashi (Japanese soup stock), Mentsuyu (noodle soup base) or Ponzu Sauce. Don’t throw these leftover kombu pieces away! We’ll make them into delicious Simmered Kombu called Kombu Tsukudani.
What’s Kombu Tsukudani?
Tsukudani (佃煮) is seafood/fish, shellfish, meat, seaweed, or vegetable that has been simmered in sweet and savory sauce (typically with soy sauce, sugar, mirin) for a long time. It usually has an intensely sweet and savory flavor, which helps preserve the ingredients.
Because of the strong flavor, Tsukudani has been served as a side dish to accompany plain steamed rice since the Edo period (1600s-1800s). We call it the Gohan no Okazu (ご飯のおかず), or rice side dish, as it’s eaten with steamed rice as a flavoring agent.
Tsukudani is always served and eaten chilled from the refrigerator and will not be cooked again prior to eating.
Kombu Tsukudani (昆布の佃煮) is one of the most common tsukudani, and I think it’s the best way to use up all your used kombu.
Did You Know Kombu has Varieties?
Do you know which type of kombu are you using? If you are new to Kombu, check out my Kombu post which I discuss different types of kombu.
For the best texture of Kombu Tsukudani, I think Hidaka Kombu (日高昆布) is the most suitable choice. It achieves tenderness a lot faster than the other types of kombu.
If you are like me who use different types of kombu in your cooking, I highly recommend freezing the used kombu separately based on the variety. Then you can cook the same type of kombu at the same time for a consistent result.
3 Tips on Tenderizing Kombu
Before you start cooking, it’s good to know that some kombu can be hard to eat as it takes a long time to get tender. Here are my tips for making delicious, tender Kombu Tsukudani.
1. Choose the right type of kombu
If you plan to make kombu Tsukudani, it might be a good idea to pick the tender variety of kombu such as Hidaka Kombu. But sometimes you just have to use whatever kombu you have. Then try my next tip #2.
2. Add rice vinegar while simmering
In Japan, kombu is often cooked with a little bit of rice vinegar, which tenderizes the kombu. Don’t add too much though. You don’t want the Tsukudani to taste vinegary.
3. Refill water and cook until tender
If the kombu hasn’t turned tender after simmering for 20-25 minutes, add some water and continue to simmer until it gets to the right texture.
- Freeze Used Kombu: We don’t have to make Kombu Tsukudani right after you have used kombu. Freeze those used kombu pieces in a glass container and put away in the freezer until you have time or you have enough kombu to make Tsukudani.
- Great Meal Prep Dish: Tsukudani is a wonderful side dish to add to your meal prep dish collection. It lasts for 2 weeks in the fridge and it’s perfect to go with simple steamed rice!
- Add Some Kick: I recommend adding some chopped dried red chili pepper (赤唐辛子) to this dish. If you like it spicy, you can add two pieces, but one is good for our family, just enough to add some kick.
Japanese Ingredient Substitution: If you want to look for substitutes for Japanese condiments and ingredients, click here.
Kombu Tsukudani (Simmered Kombu)
- 2 oz used kombu (kelp) (I used Hidaka Kombu from making dashi; Hidaka Kombu is tender and easy to cook while Ma Kombu and Rishiri Kombu are thick and hard to cook. Check out the different types of kombu.)
- ½ tsp sesame seeds
- Gather all the ingredients.
- Cut the kombu into thin strips.
- Remove the seeds from the dried red chili pepper and cut the pepper into thin rounds.
- Transfer the kombu into a medium saucepan. Add water, mirin, and sake.
- Add rice vinegar, soy sauce, sugar, and katsuobushi.
- Add the red chili pepper and bring the liquid to a boil over medium heat.
- Once boiling, reduce heat to low and simmer until the liquid is almost evaporated, about 20-25 minutes. If kombu is still not tender, add water and continue to cook.
- Sprinkle sesame seeds and ready to serve.
- Keep the Tsukudani in the refrigerate and consume within 2 weeks.