Kelp may still seem like a specialty ingredient to many people in North America, but in China, Japan, Korea, and other parts of Asia, it has been eaten for generations.
It is commonly used in soups, cold appetizers, hot pot, braised dishes, and broths. You can usually find it in Chinese, Korean, or Japanese supermarkets in dried, salted, shredded, or knotted form.
Kelp is also becoming more popular in Western diets because it is low in calories and naturally contains iodine, fiber, potassium, magnesium, calcium, and other minerals.
What Is Kelp?
Kelp is a type of large brown seaweed that grows in cool ocean water.
In Chinese cooking, kelp is often called haidai and may be sold as long sheets, strips, shredded kelp, or kelp knots. Japanese kombu is also a type of kelp. It is especially well known for making dashi, the savory broth used in many Japanese dishes. Wakame is different. It is thinner and softer than kombu and is commonly used in miso soup and seaweed salad.
In simple terms:
Kombu is usually used for broth.
Wakame is soft and works well in soups and salads.
Chinese-style kelp is often eaten directly as a vegetable.
What Does Kelp Taste Like?
Kelp has a mild salty and savory flavor with plenty of natural umami. It is not usually strongly fishy. Depending on how it is cooked, the texture can be slightly crunchy or very soft. This makes it useful in many dishes, from refreshing cold salads to rich soups and hot pot.
Is Kelp Healthy?
Kelp is nutrient-dense while being relatively low in calories. It contains dietary fiber and minerals such as potassium, magnesium, calcium, and iodine. Iodine is especially important because the body needs it to produce thyroid hormones.
However, kelp can contain very large amounts of iodine, and the amount varies by type. More is not always better. Eating kelp as part of a balanced diet is very different from consuming large amounts as a supplement. People with thyroid conditions should be particularly careful with very high-iodine foods.
Kelp and Digestion
Kelp contains soluble fibers such as alginate. These fibers absorb water and can help support normal digestion and bowel movements. This is one reason seaweed fits naturally into a diet that already includes vegetables, grains, beans, and other fiber-rich foods. Rather than treating kelp as a cure for digestive problems, it is better to think of it as another useful source of dietary fiber.
What About Heart Health?
Kelp contains potassium, fiber, and several naturally occurring compounds that are being studied for their possible role in cardiovascular and metabolic health. That does not mean kelp alone can prevent high blood pressure or heart disease. The bigger benefit is how it fits into a balanced meal. For example, a soup made with kelp, tofu, mushrooms, and vegetables can be filling and nutritious without being especially high in calories. One thing to watch is sodium. Salted kelp can be very salty, so it should be soaked and rinsed well before cooking.
Can Kelp Prevent Cancer?
You may see claims online that kelp prevents cancer. Current research does not support using kelp as a cancer-prevention or cancer-treatment food. Seaweed does contain interesting compounds such as fucoidan and other polysaccharides, and researchers continue to study them, but that is very different from proving that eating kelp prevents cancer. Kelp is best appreciated as a nutritious food rather than a medicine.
Where Can You Buy Kelp?
Kelp is easy to find in most Asian supermarkets.
Common options include:
- Dried kelp sheets
- Shredded kelp
- Kelp strips
- Kelp knots
- Salted kelp
- Kombu
- Dried wakame
The best type depends on what you want to make. Kombu is ideal for broth. Shredded kelp works well in cold salads. Kelp knots are good for soup, hot pot, and braised dishes. Wakame is best for quick soups such as miso soup.
How to Prepare Dried Kelp
Dried kelp expands a lot after soaking, so start with a small amount.
For Chinese-style dried kelp, soak it in water until it becomes soft and flexible. Thick kelp may take longer.
Rinse it thoroughly after soaking. If you are using salted kelp, change the water and rinse several times to remove excess salt.
Kombu used for Japanese broth is prepared differently. It is usually soaked or gently heated in water to extract flavor. If you see a white coating on dried kombu, do not worry. It is normal and contributes to its savory flavor.
Chinese Spicy and Sour Kelp Salad
One of the easiest ways to eat kelp is Chinese cold shredded kelp salad. It is sour, spicy, garlicky, and refreshing.
Ingredients
- Rehydrated shredded kelp
- 5 cloves garlic, minced
- 1 tablespoon light soy sauce
- 2 tablespoons Chinese black vinegar or rice vinegar
- 1/2 tablespoon oyster sauce
- A small pinch of sugar
- Chili oil to taste
- A few drops of Sichuan pepper oil
- Cilantro
- Scallions
Instructions
- Soak and rinse the kelp thoroughly. If necessary, cut it into thin strips.
- Bring a pot of water to a boil and cook the kelp for about 3 to 5 minutes. Cook a little longer if you prefer a softer texture.
- Drain and rinse under cold water.
- Mix the garlic, soy sauce, vinegar, oyster sauce, sugar, chili oil, and Sichuan pepper oil.
- Pour the dressing over the kelp and toss well.
- Finish with cilantro and scallions.
- The salad can be eaten right away, but it often tastes even better after chilling in the refrigerator.
Simple Kelp Soup
Kelp also works very well in clear soups.
- A simple broth can be made with dried anchovies, kombu, scallions, and water.
- Simmer gently until the broth becomes flavorful, then strain it.
- Add soaked seaweed, tofu, mushrooms, egg, or thin slices of meat.
- Finish with scallions and a few drops of sesame oil.
This type of light seaweed soup is common across many Asian home kitchens and is easy to adjust based on whatever ingredients you already have.
Easy Miso Soup with Wakame
For miso soup, wakame is usually a better choice than thick kelp.
You only need a few ingredients:
- Dashi or water
- Dried wakame
- Tofu
- Miso paste
- Scallions
Soak the wakame briefly in water. It expands quickly, so you only need a small amount. Heat the broth and add the tofu. Lower the heat, dissolve the miso into the broth, then add the wakame and scallions. Avoid boiling the soup aggressively after adding the miso. This is one of the easiest ways to start cooking with seaweed at home.
Kelp vs. Wakame
Kelp and wakame are both brown seaweeds, but they are not exactly the same. Kombu is thick and firm and is often used to make broth. Wakame is thinner and becomes soft after soaking. Chinese kelp is often prepared as a vegetable and can be cut into strips, tied into knots, or added directly to soup.
If you are shopping in an Asian supermarket, checking the product name and intended use is more useful than simply looking for the word “seaweed.”
Can You Eat Kelp Every Day?
Kelp can be part of a healthy diet, but eating large amounts every day is not necessary. Because some kelp contains very high levels of iodine, regular large servings may provide more iodine than the body needs. It is better to enjoy kelp in moderate portions and rotate it with other vegetables and seaweeds such as wakame and nori. Also keep an eye on sodium if you regularly eat salted or heavily seasoned seaweed products.
Final Thoughts
Kelp is not a new health trend in Asia. It has been an everyday ingredient for generations. It is affordable, easy to store, rich in umami, and works in everything from cold salads to soups and hot pot. For anyone new to kelp, start with something simple. Try a Chinese spicy kelp salad, add wakame to miso soup, or use kombu to make a homemade broth. Once you learn how to soak and prepare it properly, kelp is one of those ingredients that is surprisingly easy to keep in your kitchen.
