A Guide to All You Need To Know about Kombu

You might have heard of Kombu, a type of Japanese seaweed otherwise known as the “King of Seaweed”. For many Japanese dishes, Kombu is a key ingredient to give it that authentic Japanese taste. In this article, we are going to discuss everything you must know about this magical ingredient!

What is Kombu?

Kombu (Japanese: 昆布) is an edible sea vegetable belonging to the brown algae family. This ingredient is used extensively in Japanese cuisines, especially in soup stock (dashi) and to make simmered seaweed (tsukudani). It contains a lot of glutamic acids, which act as a flavour enhancer and has many health benefits. Due to its richness in nutrients, kombu is recommended and suitable for vegans and people who follow a plant-based diet.

Where does it come from?

90% of the kombu harvested in Japan is found in the sea around the Hokkaido area, in the north of Japan. This area is rich in minerals, providing an ideal environment that produces high-quality and flavourful kombu.

Flavour profile

There are many layers of Kombu, depending on their age. First-year kombu is quite thin hence the taste is not as rich. Second-year kombu is richer in taste, hence more aromatic and has more depth in flavour. They are often harvested from July to September. To make Japanese soup stock (dashi), second-year kombu is often preferred for the best flavour.

Due to its high concentration of glutamic acid, kombu has a umami flavour. The taste is not fishy at all, but more like a mushroom-like flavour. It is definitely very distinctive!

4 Main Types of Kombu

Ma Kombu

Hidaka Kombu

Rishiri Kombu

Rausu Kombu

Reference:(*) NPO Umami Information Center

How to Distinguish High-Quality from Bad-Quality Kombu?

In order to enjoy all the health benefits and optimal flavour of Kombu, it is important for you to know how to identify high-quality Kombu. The picture above shows an example of what it should look like. We will share with you some of our tips below:

1. Look for minimally processed Kombu

For most types of Kombu, they will be harvested, cleansed gently to remove sand and dried to be packaged. Some Kombu might need to undergo a maturation process (kuragakoi) to remove the heavy seaweed odour but in general, Kombu should not be heavily processed with any harsh chemicals.

2. Have a relatively smooth surface, without excessive holes, spots and bumps

The surface of the Kombu should be fairly smooth and consistent, free of scars like holes, spots and bumps.

3. Free of dirt and excessive amount of sands

High-quality Kombu should be harvested from clean water so it should not have any dirt and excessive sand residues.

4. Still have some white-powdery deposit

The white powdery deposit is known as mannitol, which is responsible for creating that unique umami flavour. High-quality Kombu would have a high amount of this white deposit on the leaves.

5. Should have greenish-brown colour

Although the colours do vary between different Kombu varieties and it is difficult to say exactly what the colour should be, it should generally vary between different shades of green to black.

Ways to Use Kombu

How to Make Kombu Dashi

With Kombu, it is essential we learn how to make dashi. Making dashi is very simple, yet dashi is a key and critical ingredient in many Japanese dishes that cannot be missed! There are 2 ways to make dashi, either by a hot brew or a cold brew. Please refer to the recipe below to learn how to do this!

Warm & Cozy Kombu Chicken Soup

With this broth, you can go ahead and make any dishes ranging from a delicious bowl of ramen to a flavourful hot bowl of soup. Today, let’s make a Kombu Chicken Soup!

Easy & Simple Kombu Tsukudani

If you’re wondering what to do with the leftover Kombu used to make the broth, this next recipe will be just the right recipe for you. Here, we are making a type of seasoning called Tsukudani, which is delightful when eaten with rice. You should totally give this a try.

Apart from some of the recipes mentioned here, you can also make other types of dishes such as tofu and egg soup, ramen, chicken hot pot, and different types of drinks such as kombu tea. Since there are so many delicious recipes specifically made for each type of kombu depending on their texture and flavour, please visit our product page for Hidaka, Rishiri and Rausu kombu to find out more!

Nutritional Values

Kombu kelp is known as the strongest alkaline food. It contains many vital nutrients to help our body be strong and healthy. Kombu specifically contains a high amount of antioxidants, a rich source of vitamins, minerals, and iodine, and a great source of omega-3 fatty acids as well as fibres. For this reason, kombu is one of the most popular seaweed used in a variety of cuisines.

Let’s take the example of Hidaka kombu. For each sheet containing 10g of kombu, it has 15 calories. Due to its extremely low fat and cholesterol nature & high volume of fibre, it is considered to have an anti-obesity effect on the body. Furthermore, there has been research done to show that the fucoxanthin substance in seaweed may help to control your blood sugar.

Reference: Phenolic Compounds from Edible Algae: Bioactivity and Health Benefits

5 Health Benefits of Kombu

Benefit #1: Strong bones and teeth

Benefit #2: Glowing skin and smooth hair

Benefit #3: Easy digestion

Benefit #4: Support cardiovascular health

Benefit #5: Strong eyes and immunity

Is Kombu toxic?

While kombu is not toxic, over-consuming kombu could lead to abnormal thyroid function in the long-term for people, and especially for individuals with underlying thyroid disorders. This is due to its growing method of being in deeper water, making it naturally contain a very high concentration of iodine. Therefore, it is recommended to boil kombu in water for 15-30 minutes to reduce its iodine concentration. This means that processed and cooked seaweed usually do not carry a significant amount of iodine to pose health risks, so you shouldn’t be worried when consuming them! Also, as a safety reminder, please remember to read the instructions on the packaging to know the recommended intake!

Reference: Suppression of Thyroid Function during Ingestion of Seaweed “Kombu” (Laminaria japonoca) in Normal Japanese Adults

Where to Buy Kombu?

You should be able to find kombu in any Japanese or Asian supermarket. Some other supermarkets like Whole Foods and Walmart also carry kombu in the Asian/International food aisle or more specifically, look for the dried seaweed aisle. You could also purchase kombu from here that delivers internationally!

Kombu FAQs

What is the white powder on my Kombu?

That is not mold or dirt, but this powder is known as mannitol that gives the kombu that umami flavour.

How should I clean my Kombu for cooking?

Kombu is generally clean so it is not necessary for you to rinse it in running water at home. This will strip off the white powder and lose the umami flavour. Instead, please use a damped cloth to gently wipe it.

Does Kombu have a fishy smell?

Even though it comes from the sea, it does not have a strong, fishy odour.

What is the difference between Kombu and Nori?

Nori is a red-algae seaweed, whereas kombu belongs to the brown algae family. Nori has a lighter colour and is much more delicate than kombu, therefore it is often used for sushi wrapping. Kombu, on the other hand, has a darker colour and thicker leaves, therefore much more suitable to make dashi.

Please click here to read more about Nori

What is Nori and The Must-Try Nori Recipes   Nori, the delicious dark-green sheets of edible seaweed that often wrapped around your sushi. Nori has rich natural umami flavor from the seaweed, eve...

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