The Complete Guide to Korean Seaweed (Gim): Types, Uses & Benefits

If you’ve ever enjoyed Korean food, you’ve probably encountered gim (김) — those crispy, savory sheets of seaweed that appear in kimbap rolls, as a side dish, or as an addictive snack. But what exactly is gim, and why has this ancient Korean ingredient become a global superfood sensation?

Gim is a generic term for edible seaweeds dried for use in Korean cuisine, consisting of various species in the genera Pyropia and Porphyra. More than just a wrapper for rice rolls, gim represents centuries of Korean coastal culinary tradition and offers remarkable nutritional benefits that modern science continues to validate.

In this comprehensive guide, we’ll explore everything you need to know about Korean seaweed — from its fascinating history and diverse types to its impressive health benefits and countless culinary applications.

Table of Contents

1. What Is Gim? Understanding Korean Seaweed
2. The Rich History of Gim in Korea
3. How Does Gim Differ from Japanese Nori?
4. Types of Korean Seaweed (Gim)
5. Health Benefits of Gim
6. How to Use and Store Gim
7. Where to Buy Quality Gim

What Is Gim? Understanding Korean Seaweed

Gim (pronounced "keem" with a soft ‘g’) is the Korean word for laver, a type of red algae that grows along the rocky coastlines of the Korean peninsula. The earliest mention of edible seaweed in Korea is recorded in the Memorabilia of the Three Kingdoms (1280s), documenting that people of the Silla period would use gim as part of their dowries.

The production process is similar to papermaking: fresh seaweed is harvested, chopped into fine pieces, spread onto screens, and dried into thin, papery sheets. The most commonly cultivated species of laver in Korea is the P. yezoensis followed by the P. tenera, with algae that only grows in the oceans surrounding the southern parts of the Korean peninsula.

What makes gim distinctly Korean is the roasting process. Unlike some other seaweed products, gim is typically roasted to create a crispy texture, and often seasoned with sesame oil or perilla oil and a touch of salt, giving it an irresistible umami flavor with a hint of nuttiness.

The Rich History of Gim in Korea

The story of gim cultivation in Korea is steeped in legend and historical documentation. According to legend, gim was named after Gim Yeoik (1606–1660) — the first person to have cultivated gim after seeing a drifting oak branch covered in it on Taein Island during the reign of King Injo (1623–1649).

Before systematic cultivation, it is conjectured that the gim of the early period was harvested from rocks and driftwood rather than being cultivated. Historical records show gim’s importance in Korean society: the Veritable Records of the Joseon Dynasty describe gim as the representative product of Chungcheong, Gyeongsang, and Jeolla Provinces, and King Seonjo was urged to soothe the hardship of the country’s eastern coastal people who were required to produce and submit gim as a royal offering.

Gim cultivation continued to expand throughout the southern coastlands, with early methods using bamboo or oak sticks eventually replaced by newer methods utilizing nets, developed in the 19th century. Floating rafts have been used for mass production since the 1920s.

Today, gim production is a major industry in Korea. Around 19,500 tonnes of gim are produced in Korea annually, with naturally grown gim insufficient to meet market demand, so much of it is cultivated commercially.

How Does Gim Differ from Japanese Nori?

Is Gim the Same as Nori?

This is one of the most common questions about Korean seaweed. The short answer: gim and nori are similar but not identical.

Both gim and nori refer to laver — nori is the Japanese name for the same type of seaweed, so when shopping, if it comes from Korea, it will likely be labeled "gim" while products from Japan will be labeled as "nori".

However, there are key differences:

Production Method Korean gim begins as raw seaweed carefully cut into fine pieces, then transformed into sheets and dried, resulting in a product with a satisfying crunch. Japanese nori is finely chopped and crushed into a liquid state, then spread thinly and dried through a process called "suko," creating gossamer-thin sheets that practically melt on your tongue.

Flavor and Seasoning Gim is different from nori in that it is seasoned with sesame oil and salt. Korean gim boasts a robust flavor profile, often enhanced with sesame oil, resulting in a crispy texture that provides a satisfying bite. Japanese nori, in contrast, is lightly seasoned to highlight the natural umami of the seaweed, with its paper-thin texture dissolving effortlessly.

Thickness and Texture Korean laver is usually a bit thinner and glossier than nori. For kimbap (Korean rice rolls), gim sheets are typically thicker than traditional sushi nori to provide structural integrity when rolled with various fillings.

Both are nutritious and delicious — the choice between them often comes down to personal preference and the specific dish you’re preparing.

Types of Korean Seaweed (Gim)

Not all gim is created equal. Korea produces several distinct varieties, each with unique characteristics:

1. Jaerae Gim (재래김)

Jaerae Gim, also known as Joseon Gim, is a unique Korean style gim made very thin. When held up against the light, you’ll see hints of light brown and green colors. The size is larger (7.5 in x 10.5 inches) than kimbap gim. This is the most commonly consumed type in Korean households and the variety typically sold as roasted seaweed snacks in international markets.

2. Dol Gim (돌김)

Dol gim literally means "rock seaweed," and as the name suggests, is grown on rocks. Dol gim is rougher and a little thicker, with some saying it has more flavor, though others may not prefer the rougher texture.

3. Parae Gim (파래김)

Parae gim has Ulva intestinalis (sea lettuce) mixed in with laver when dried, giving it a greener tint and the extra flavor of sea lettuce. It has a distinctive herbal flavor and smooth texture.

4. Kimbap Gim (김밥김)

Kimbap gim is gim used for making Korean seaweed rice rolls. This gim is made thicker and smaller (about 7.5 in x 8.5 inches) to fit well with a kimbap mat. When seen against a light, it appears totally black and solid — basically the same dried seaweed as Japanese-style nori used for sushi.

5. Gopchang Gim (곱창김)

Gopchang gim is made from the first harvest of the year, known to have more intense flavor and a thicker, curly shape.

Special Mention: Gamtae Gim

Gamtae gim is a special kind grown under controlled conditions in the clearest waters off the west coast of South Korea. It’s a type of brown algae that almost looks grass-like when dried, with a unique texture like a paper-thin woven grass mat and a unique taste — much more fresh and herbal compared to regular gim. Gamtae gim is used by Michelin-star restaurants in the United States and Belgium.

Health Benefits of Gim: Why Korean Seaweed Is a Superfood

Is Korean Seaweed Healthy?

Absolutely! Gim is considered a nutritional powerhouse, and science backs up its superfood status.

Rich in Essential Nutrients

Gim contains protein, thiamine, riboflavin, and vitamins A, B6, and B12, making it very nutritious. It also has a high content of mineral salts, like iodine and iron, and essential amino acids.

Laver is the best dietary source of iodine, which helps thyroid glands, and is high in iron and protein. It contains vitamins and minerals like vitamin A, vitamin B2, vitamin C, and vitamin D and is high in antioxidants that help to protect cells from damage. Laver also contains 22% of a person’s daily potassium requirement. Seaweed has 67 times more vitamin A than eggs and 1.5 times more vitamin C than oranges.

Thyroid Support

Seaweed contains an amino acid called tyrosine, which is used alongside iodine to make two key hormones that help the thyroid gland function properly. This makes gim particularly valuable for thyroid health, which regulates metabolism, energy levels, and numerous bodily functions.

Low Calorie, High Nutrition

Gim is an ideal snack for those watching their weight. A typical serving provides substantial nutrients while remaining very low in calories — making it a smart choice for health-conscious snackers looking to replace chips or other processed snacks.

Antioxidant Properties

Gim is high in antioxidants that help to protect cells from damage. These compounds combat oxidative stress and may contribute to overall cellular health and longevity.

Important Considerations

While gim is incredibly nutritious, moderation is key. It’s important to eat gim in moderation due to its high levels of sodium and iodine. Excessive iodine intake can harm thyroid health, with 1,100 mcg being the tolerable upper limit for adults.

Additionally, seaweed can contain toxic heavy metals such as cadmium, mercury, and lead. To minimize risk, purchase organic gim from reputable sources and consume it as part of a varied diet.

How to Use and Store Gim

How Do Koreans Eat Gim?

The versatility of gim makes it a staple in Korean cuisine:

As a Side Dish (Banchan) When eaten as a banchan, dried sheets of gim are toasted with sesame oil or perilla oil, sprinkled with fine salt and cut into squares. It’s served alongside rice and other dishes at virtually every Korean meal.

In Kimbap For use in gimbap, the sheets are not toasted, but are instead used in their original dried state. The sheets wrap around seasoned rice, vegetables, and sometimes meat or fish to create portable, delicious rice rolls. For more information on how gim is used in traditional Korean cooking, check out our detailed guide on Korean laver.

As a Snack Gim is a common side dish, or banchan, on Korean restaurant tables and sometimes takes the place of potato chips. It’s a bit crispy, tastes good, and is actually healthy.

As a Garnish Torn or shredded gim adds visual appeal, texture, and umami flavor to soups, stews, rice bowls, and noodle dishes.

In Special Dishes Gim may be deep-fried to make coated fritters called bugak.

How Should I Store Gim to Keep It Crispy?

You don’t want to expose laver to air for too long. Take out however much you’ll consume at the time and keep the rest in a resealable container that can be kept in a cool, dry place away from sunlight. If keeping it for a longer time, place it in the freezer.

Pro tip: Include a silica gel packet (often found in packaged gim) in your storage container to maintain maximum crispness.

Can I Toast Gim at Home?

Yes! Heat a large pan over medium-high to high heat until you see smoke. Place a sheet of gim with the coated side facing the hot pan — it will instantly shrink as it roasts. The color will turn slightly green. After 3 seconds, flip and roast the other side. This entire process should take about 10 seconds total per sheet.

What Should I Look for When Buying Gim?

When buying gim, look for ones that don’t look reddish, as that is a sign that it was either not stored properly or is too old. Kimbap gim should look black and jaerae gim should look brownish in general but have specks of green — it should not have any tint of red.

Popular Brands:

1. Daechun seaweed, Wang Korean Roasted Seaweed, and NongHyup Roasted Sesame Oil Laver Seaweed are good options.
2. Kwangcheongim was founded in 1970 and has since exclusively focused on creating the most delicious gim, with the largest and most advanced gim production facility.

Where to Purchase:

1. Korean grocery stores
2. Asian supermarkets
3. Online retailers (Amazon, Weee!, Korean specialty food websites)
4. Specialty health food stores

When purchasing online, check expiration dates and read reviews to ensure freshness and quality.

Final Thoughts: Why Gim Deserves a Place in Your Kitchen

From its humble origins harvested from coastal rocks to its current status as a globally recognized superfood, gim represents the best of Korean culinary tradition — simple, nutritious, and absolutely delicious. Whether you’re making kimbap at home, looking for a healthier snack alternative, or simply want to add more nutrients to your meals, Korean seaweed is an excellent choice.

Korean gim, or laver, is one of those superfoods that is not only healthy but is so delicious too. Whether eating it wrapped around rice, as a garnish, or as a snack, this is a must-eat Korean food.

Next time you’re exploring Korean cuisine, pay attention to those crispy, savory sheets — they’re more than just a wrapper or garnish. They’re a connection to centuries of coastal Korean culture and a powerhouse of nutrition that modern science continues to celebrate.

Ready to experience the delicious world of Korean seaweed? Start with a simple roasted gim snack pack, and you’ll soon discover why Koreans have treasured this ocean vegetable for over a millennium. Have you tried gim before? What’s your favorite way to enjoy Korean seaweed? Share your experiences in the comments below!