Seaweed – a tasty treat beloved around the world

Goat Rock Beach

If I took one of those psychological word pairing tests and the first word was seaweed, hands down my response as a match would be sushi.  I suspect I am not alone that since my first introduction to eating seaweed involved this wonderful finger food, it would be a life long association.  However I’ve come to realize through my travels, meeting people and general nosiness of what is on the other person’s dish that seaweed is found well beyond the confines of sushi restaurants and  I’ve been selling the versatility of this wonderful foodstuff short, for example, in England – laver, in Ireland – dulse, in Latin America – carola, and karengo in New Zealand.  In fact, its uses like so many ingredients, are limited only by the imagination of the cook, and I felt the need to expand my wings a bit.

A bit about seaweed

If your idea of seaweed is similar to mine was, that dried sheet that tasted briny, and if you were not careful could stick to the roof of your mouth like glue.  Well there’s more, many more, to the tune of 7,000 varieties although only 160 are commonly used as food – with about 25 varieties being green, 81 are of the red-seaweed persuasion and the remaining 54 fall under the brown seaweed category.

Seaweeds are a food staple for many countries. For some, conventional land farming failed to address the needs of people, so they turn to sea-farming.  India for example, has a long coast line, stretching some 7,000 km with more than 624 species of seaweeds found in its coastal waters.  Research on increasing consumption of seaweed is underway.

Japanese beach - photo courtesy of R-G

For centuries, folks from China, Japan and Korea have smartly incorporated seaweed into their cuisine, and as  these people migrate around the world, this custom has spread with them.  Recently, France is attempting to introduce seaweed into the European cuisine, with some success, although it is still regarded as an exotic component of the menu. It has gained more acceptance in regions like California and Hawaii, with large Japanese communities creating a built- in demand, and inquisitive food lovers, that either find the stuff on grocery shelves or in restaurants and give it a try.  In addition to their versatility and umami flavor, they are incredible nutritious.

On the east coast of United States of America and Canada, around Maine, New Brunswick and Nova Scotia, companies are cultivating seaweeds onshore, in tanks, specifically for human consumption, and their markets are growing, both in those two countries and with exports to Japan.  Ireland and Northern Ireland are showing a renewed interest in seaweeds that were once part of the traditional diet.

Seaweed or sea vegetables fall into three basic categories, or color coding:

  • Green – These sea veggies most resemble their surface dwelling kin, so for the beginner seaweed eater, this group might be a good place to start.
  • Red – These fair weather beauties do not fare as well in the colder climate so they are found in the tropical and subtropical water.  According to Harold McGee, in his book, On Food and Cooking, they owe their color to special pigment, protein complexes that are sensitive to heat.  Consequently, when cooked their colors can change dramatically from red to green.  Because of the way they store their energy in the form of starch, this group provides gelling properties found in Agar-agar and carrageen.
  • Brown – These fellas like the temperate waters and can be pretty aggressive in staking their claim (wakame)

Types of Sea Veggies

Nori or laver (Porphyra)

This is the purplish-black seaweed often seen disappearing into  sushi connoisseurs mouth comes mostly from Japan, Korea and China.  In Japan’s list of products from marine culture, ranks nori the highest, followed by oysters, yellowtails and wakame.  Nori grows as a very thin, flat, reddish blade, and is found in most temperate zones around the world.

nori doing its thing

While Porphyra can be collected from natural sources, most are now cultivated.  Porphyra has an unusual life cycle that was not understood until the early 1950s. Until then no one knew where the spores came from, so there was little control over the cultivation process.  The seaweed, as we know it, sheds spores that settled on neighboring mollusk shells.  In the controlled cultivation these spores are deliberately placed beneath the blades of the seaweed.

Processing of wet Porphyra into dried sheets of nori is highly mechanized, rather like the paper-making process. The wet Porphyra is rinsed, chopped into small pieces and stirred in a slurry. It is then poured onto mats or frames, most of the water drained off, and the mats ran through a dryer. The sheets are peeled from the mats and packed for sale.  This product is called hoshi-nori, as opposed to yaki-nori, which is toasted to bring out the flavor.

Nori is often a sushi wrap, or after a short baking or toasting, cut into pieces and sprinkled over rice or noodles. In China it is mostly used in soups and for seasoning fried foods.

Hijiki or Hiziki (Sargassum fusiforme)

This brown sea vegetable growing wild on rocky coastlines around Japan, Korea, and China. It is a traditional food and part of the Japanese diet for centuries.

Hijiki is green to brown in colour when found in the wild.  The seaweed is processed by first boiling and then drying which turns hijiki black.  Dried hijiki is prepared for cooking by first soaking it in water then cooked with ingredients like soy sauce and sugar to make a dish.  Hijiki is normally eaten with other foods such as vegetables or fish.

Cooking idea:  Sweet Potato Gnocchi with Nori Butter via 5 Star Foodie.

Aonori or green laver (Monostroma and Enteromorpha)

These two green seaweed genera are cultivated in Japan. Enteromorpha cultivation has also been attempted in the Republic of Korea but with limited success.

Monostroma latissimum occurs naturally in southern Japan where it is cultivated in shallow, calm waters, such as are found in bays and estuaries.

It can then either be processed into sheets and dried, as described for Porphyra, for sale, or dried and boiled with sugar, soy sauce and other ingredients to make “nori-jam”.

Sea Lettuce (Ulva lactuca)

photo from

“Sea lettuce” describes a thin green seaweed, collected from the wild and often added to the above two seaweeds as part of aonori.  Several species are considered food in Scandinavia, Great Britain, Ireland, China, and Japan (where it is known as “aosa”).

Kombu or haidai (Laminaria japonica)

Kombu is the Japanese name for the dried brown algae derived from a mix of Laminaria species harvested mainly on Hokkaido.  The Japanese have eaten kombu for several centuries.  The naturally growing plants are biennial and are harvested after 20 months.  As demand grew in the 1960s, attempts were made to develop artificial cultivation methods, but the two-year cycle meant the costs were too high. In the 1970s, forced cultivation was introduced, reducing the cultivation period to one year, similar to the system developed in China in the early 1950s. Today, about one-third of Japan’s requirements come from cultivation.

Haidai is the Chinese name for Laminaria japonica, that was accidentally introduced to China by the Japanese in the late 1920s.  Prior to that time, China had imported it from Japan and Korea.  China had no natural sources of Laminaria but it magically appeared in the northern city of Dalian in 1927 with the importation of logs from Hokkaido.  The Japanese, who then occupied that part of China, tried to increase the growth.  In China, haidai is regarded as a health vegetable because of its mineral and vitamin content, especially in the north, where green vegetables are scarce in winter months. It is usually cooked in soups with other ingredients. In Japan, it is used in daily with fish. Kombu tea is like green kombu but shaved a second time so the shavings are like tea leaves. Other variations are used to produce different kombu types. In cooking, green kombu is boiled with meat, fish and soups. Powdered kombu is added to sauces and soups, and to rice. Green kombu and tea kombu are used to make a tea-like beverage.

Wakame, quandai-cai (Undaria pinnatifida)

wakame and agar salad - photo courtesy of R-G

Undaria pinnatifida, a brown seaweed, occurs on rocky shores and bays in the temperate zones of Japan, Korea and China. It has been spread, probably via ship ballast water, to France, New Zealand and Australia.  Korea is the largest producer of wakame.  It is both loved and reviled at the same time.  Loved – it is widely used in miso soup – hated as it has been nominated as one of the top 100 most invasive species, according to the Global Invasive Species Database.  In 2009, it was found in the San Francisco Bay and agressive efforts are underway to remove it before it spreads.

Hiziki (Hizikia fusiforme)

Hizikia fusiforme is a brown seaweed with a finer frond (leaf) than wakame and kombu. It is collected from the wild in Japan and cultivated in Korea, and is on the southern shore of Hokkaido. About 90% of Korean production is exported to Japan.

Em offers these wonderful tofu hijiki squares recipe.  If you have not checked out Kitchen M, I strongly encourage you – wonderfully inventive food from a Bay Area dietician coupled with incredible photography.

Mozuku or Makusa (Cladosiphon okamuranus)

Mozuku is a brown seaweed harvested from natural populations in the tropical climate of Japan’s southern islands – mainly around Okinawa.  After washing to remove the salt, it is used as a fresh vegetable, eaten with soy sauce and in seaweed salads.

Sea grapes or green caviar (Caulerpa lentillifera, Caulerpa racemos)

photo courtesy of Robert-Gilles

There are many species of the genus Caulerpa, but Caulerpa lentillifera and C. racemosa are the most popular edible ones. Both have a grape-like appearance and are used in fresh salads. They are commonly found on sandy or muddy sea bottoms in shallow protected areas.

Dulse (Palmaria palmata)

Dulse, a red algae with leathery fronds (leaves) also goes by the names sea parsley, dilsk, creathnach and söl (Iceland). It is collected by hand by harvesters plucking it from the rocks at low tide. It is perennial and when either plucked or cut, new growth appears from the edge of the previous season’s leaf. It is harvested mainly in Ireland and the shores of the Bay of Fundy in eastern Canada. Inferior dulse, usually because of poor drying, is broken into flakes or ground into powder for use as a seasoning; sometimes it is added to corn chips. In Nova Scotia and Maine, dried dulse is often served as a salty cocktail snack by bar owners as makes the bar patrons thirsty – sneaky devils.

In Ireland, it is sold in packages and looks like dark-red bundles of flat leaves. It is eaten raw, like chewing tobacco, or is cooked with potatoes, in soups and fish dishes. Fresh dulse can be eaten directly off the rocks before sun drying.  It can be panfried into chips, baked in an oven covered with cheese or salsa.  Finely diced it can act as a flavor enhancing substitute for MSG.   Dulse has been harvested for over 1,400 years

Irish moss or carrageenan moss (Chondrus crispus)

Irish Moss has a long history of use in foods in Ireland and parts of Europe. It is not eaten on its own, but used as a thickening agent when boiled in water.  Blancmange, a traditional vanilla-flavored pudding, is a happy consequence of this chemistry.  It is used in seaweed salads, sashimi garnishes and as a soup ingredient.

Winged kelp (Alaria esculenta)

This large brown kelp grows in areas such as Ireland, Scotland (United Kingdom), Iceland, Brittany (France), Norway, Nova Scotia (Canada), Sakhalin (Russia) and northern Hokkaido (Japan).  Eaten in Ireland, Scotland and Iceland either fresh or cooked, it is said to have the best protein among the kelps and is also rich in trace metals and vitamins, especially niacin. It is usually collected from the wild and eaten by local people, and while it has been successfully cultivated, this has not been extended to a commercial scale.

Ogo, ogonori or sea moss (Gracilaria)

ice cream toppers made with Agar-Agar

Fresh Gracilaria has been popular in Hawaii for several decades. The mixture of ethnic groups in Hawaii (Hawaiians, Filipinos, Koreans, Japanese, Chinese) creates an unusual demand and supply has at times been limited by the stocks available from natural sources.  Limu manauea and limu ogo are sold as fresh vegetables, the latter usually mixed with raw fish. In Indonesia, Malaysia, the Philippines and Vietnam, species of Gracilaria are collected by coastal people for food. People used the extracted agar to make jellies.  A wonderful example of its use can be seen here.   In the West Indies, Gracilaria is sold as “sea moss”, and is reputed to have aphrodisiac properties.  It is also a base for a non-alcoholic drink, and has been successfully cultivated for this purpose in St Lucia and adjacent islands.

Persephone’s Tears – wonderfully inventive use of agar – again thanks to 5 Star Foodie.  Pham Fatale offers up some tasty Tet recipes including Vietnamese Jello cakes, Rau Cau

Callophyllis variegata

In Chile, the demand for edible seaweeds has increased and Callophyllis variegata (“carola”) is one of the most popular.  It is a member of the red algae family and also popular in other parts of South American including Per and the Falkland Islands.

Innovation, cultivation and niche markets: the combination of these three may lead to greater success for future investors, rather than attempts to break into the large markets for nori, kombu and wakame.

Along with my fixation on sea vegetables and sushi, I have a strong tendency to classify it as a savory dish.  I stumbled across this great recipe in the Irish Farmer’ Market Cookbook by Clodagh McKenna and it is delicious.  I am lucky enough to have a store that carries carrageen nearby.

Lemony Carrageen Moss Pots

Serves 6 (they called for 4-½ oz pots, I used ramekins)


8 g (¼ oz) carrageen moss + extra for garnish
1 ¼ pint milk
4 T caster sugar
6 lemon balm leaves or the zest of 3 lemons
1 vanilla pod
2 eggs, separated


Soak the carrageen in luke warm water for 15 minutes.  Drain and place in a sauce pan with the milk, 1 T of the sugar, lemon balm and vanilla pod.  Bring to a boil then reduce heat and simmer for 30 minutes.  Strain through a sieve into a bowl, pushing the natural gelatin from the carrageen through the sieve.

Put the egg yolks in a bowl and beat in the 3 remaining tablespoons of sugar.  Whisk into the strained mixture.

Wish the egg whites until stiff peaks form.  Fold them into the mixture with a metal spoon.  Using a figure eight movement to get rid of any blogs of egg white.  Fill the pots with the mixture and chill in the fridge for about an hour until set.  Serve topped with the extra carrageen.

Other Resources:

Michael Guiry’s Seaweed Site – focus on Irish uses. He is a professor at the University of Galway

From the LA Times – A Crop from the Ocean Floor

Seaweed Used as Human Food

Shizuoka Gourmet – Seaweed: The Vegetable of the Oceans! Several of the pictures on this site are thanks to the generosity of Robert-Gilles, the Shizouoka Gourmet – much appreciated.

Update me when site is updated

35 comments for “Seaweed – a tasty treat beloved around the world

  1. March 4, 2010 at 3:25 PM

    When I’ve the possibility I’ve done salads with seaweed (sea lettuce) and of course the nori is the famous one of the menu 🙂
    I didn’t know the others and their names… really a healthy green class 🙂



  2. March 4, 2010 at 6:13 PM

    I had no idea there was such a variety of seaweed. I usually have the nori and some seaweed salad. I thought i would be turned off by it, but to my surprise, I enjoyed it quite a bit and had a second serving.

  3. March 4, 2010 at 7:32 PM

    I often go to the Asian market and stare at the packets of dried seaweed. There are so many types and I always walk away too confused to make a purchase. I think this might help. GREG

  4. March 4, 2010 at 8:58 PM

    Gosh, there are so many varieties of seaweed – I am just revolving around 2-3 types. Sometimes, I cannot tell if it is red or brown or purple seaweed since they are just too dark in color. At the same time when I buy dried seaweed in package-form, I cannot make sense of Japanese or Korean words on the package which may be telling me what it is. To me, there is just nori and kelp which I can tell the difference visually. Thanks for sharing so much info.

  5. March 4, 2010 at 9:00 PM

    Seaweed is used here in a popular local drink called sea moss. My favourite to eat is kelp. BTW thanks so much for your kind comments on my blog. You made my day today and made me blush honestly with the powerful voice comment. That coming from such an experienced blogger as yourself that I admire……well all I can say is that my husband wishes you hadn’t said a thing as his ears are ringing nonstop as I keep going on…”Hon, did I mention that oyster culture said that I have a powerful voice?” His weary response, “Yes dear, and I have to agree since you’ve told me this only like a hundred times already!” Hee Hee.

  6. March 4, 2010 at 10:54 PM

    The sea grapes look pretty cool. Other than nori, seaweed is not one of those ingredients used too often in these parts. It’s always interesting to see how people use it.

  7. March 4, 2010 at 11:08 PM

    This is making me miss home cooked Japanese food, particularly mozuku soup! I don’t think I’ve ever had sea grapes, but I’ve had almost all that you mentioned here. Great post as always!

  8. March 4, 2010 at 11:11 PM

    I have a hijiki recipe on my blog, too. 🙂

  9. admin
    March 5, 2010 at 6:46 AM

    Gera – That’s why I did the post – kept finding all these wonderful references but had no idea what to do with them or how they all fit into the big picture.

    Jenn – The more I sample this sea veggie the more I like it!

    Sippity – Hope it helps!

    Tigerfish – I’m with you – nori has been my staple but its time to expand!

    Wizzy – After reading about your sea moss – I desparately want to sample it. I’ll be on the look out for a recipe. As to your powerful voice – its very true Cannot wait to see what you do with it. =)

    Duo – I agree the sea grapes are the coolest of the bunch – I’m imagining al the fun dramatic possibilities.

    Kitchen M – Ah sorry for the onset of homesickness. I posted your wonderful recipe. Its the perfect addition as I was trying to find recipes for each of the edible seaweeds that did not have obvious foods like miso – need to fill in a few others.

  10. March 5, 2010 at 7:09 AM

    I have been wondering what else to do with seaweed – just really knowing nori. Other varieties are cropping up more frequently at the grocers. Seems like it’s time to just buy some and give it a whirl.

  11. March 5, 2010 at 7:10 AM

    Excellent article! I love the many interesting ways you can use all those different kinds of seaweed. We see it used in the 5 star restaurants a lot these days too. I would love to find those green grapes, so neat. Thanks so much for the link backs 🙂

  12. March 5, 2010 at 1:05 PM

    This is great! I like making my own miso at home and I usually toast some kind of seaweed and add it to the pot. So many varieties and not enough opportunities to try them!

  13. March 5, 2010 at 1:35 PM

    Wakakme has to be my fave seaweed……….yummy and I love the bright green colour!

  14. March 5, 2010 at 1:51 PM

    Wow1 My seaweed experience was based on sushi and crispy Chinese fried seaweed! This post opens so many new doors!!

  15. March 6, 2010 at 10:44 AM

    I so love the different sea weeds. I read a full article in Jamie’s Food magazine, the last issue. It is very useful info. You also give us allways excellent info & grand stotries about our daily food!

    But we can’t get it fresh though here in Belgium. That’s a pity!!!

  16. March 6, 2010 at 12:38 PM

    Those sea grapes are a new one on me. They look like those wasabi “caviar” eggs that are so trendy lately. Thanks for a wealth of info, as always. I love how little kids love to nosh on dried sheets of nori now. Just shows how popular it has become in all its forms.

  17. March 7, 2010 at 8:04 AM

    The sea grapes look like beads! I would love to try them. I do the same thing as Greg – stare at all of them and wonder what to do with them and leave without buying any. I would love to incorporate them more often into my food.

  18. March 7, 2010 at 8:15 AM

    This is so good to read because I’ve been wanting to use more seaweed. There are so many more options than I ever knew!

  19. admin
    March 7, 2010 at 10:34 AM

    Claudia – I’m with you, I have sheets of nori at home, and seaweed in various spices but just knew that there was so much more that it could be used for.

    5 Star – I’m on the lookout for those grapes too – I’ll let you know if I find them. Can you do the same?

    Ruth – Agreed – such a bounty of possibilities

    Sophie – I’ll have to check out Jamie’s article – sounds very interesting.

    Carolyn – they do like like caviar – definitely on the lookout.

    Reeni – Me too, but I’ve vowed to be more adventurous.

    Lisa – Agreed, the possabiliites are very interesting – I got intrigued by some recipes for seaweed bread, that I think would be really tasty.

  20. March 8, 2010 at 8:27 AM

    A wonderful and informative post. Seaweed has been a staple all my life. My mother grew up in a coastal town in South Korean and my grandfather was captain of a fishing boat. According to them seaweed soup cures all ailments and is also a must at any celebratory gathering. Most of my mother’s family back in Korea live near and work at a US Army base so we get regular shipments of the best dried seaweed (posting mail to and from the base is super cheap!). My favorite is pressed, toasted, and brushed with sesame oil.

  21. March 8, 2010 at 3:56 PM

    I LOVE seaweed! But I only used to like it when it’s toasted into nori. In Korea, it’s customary to eat seaweed soup with rice on your birthdays, and that pissed me off. My mom had to stop it so that I didn’t cry on my birthdays, lol. But now, I love seaweed in all kinds!

  22. March 9, 2010 at 6:51 AM

    I had no idea there were so many kinds of seaweed. Many years ago I experimented with different dishes which included Nori and Kelp. From what I can remember, their vitamin and health benefits are phenomenal.

    GREAT post!

  23. March 9, 2010 at 11:26 AM

    I only ate seaweed once at a Japanese restaurant in NY, but this post is very interesting!

  24. March 9, 2010 at 11:59 PM

    I’m intrigued by the seaweed beads, and want to try those someday. I adore seaweed, all varieties and all forms, especially in cold salads. I hope that invasive wakame can be harvested and turned into an asset versus a liability.

  25. March 10, 2010 at 6:13 AM

    We have some lovely Irish friends who gave us some carrageen moss but I didn’t know what to do with it. Now I do!

  26. March 12, 2010 at 4:24 PM

    Seaweeds are very healthy. Unfortunately, I’m not a big fan of their taste. Dulse is not too bad, though…



  27. admin
    March 12, 2010 at 5:56 PM

    Gastro – lucky you to have a ready source – your favorite sounds like it would be a fast favorite for me, too. Love the sound of it.

    Sophia – so glad you got beyond being pissed off and now like the stuff!

    Louise – I think they are still discovering all the remarkable benefits of these sea vegetables

    Erica – Hope you liked it and are willing to have some more.

    Christine – I know the beads have me strangely in their grasp – must try soon!

    Crystal – lucky you to have a ready supply of carrageen.

    Rosa – Glad you’re open to sampling – they are a bit of an acquired taste as I can’t really think of anything, land based they taste like.

  28. March 25, 2010 at 9:07 AM

    Awesome post! The “sea grapes” look really cool! Kind of remind me of young peppercorn.

    One interesting thing about hikiji is that it contains very high amounts of arsenic compounds and, if I’m not mistaken, is banned in some countries. The US, of course, is not one of those countries. On the other hand, it does ban bitter almonds for the same reason. ???

    You know, I don’t see my friends jumping up and down at the idea of me bringing Lemony Carrageenan Moss Pots to a party, but, being a seaweed lover, I can certainly see myself enjoying it. 🙂

  29. April 19, 2010 at 2:04 PM

    I’m intrigued by the seaweed beads, and want to try those someday. I adore seaweed, all varieties and all forms, especially in cold salads. I hope that invasive wakame can be harvested and turned into an asset versus a liability.

  30. admin
    April 19, 2010 at 2:52 PM

    Hi Leela – I was thinking the same thing about the sea grapes. Great point on the arsenic, that’s the fun with regulations, the consistency. Who knows regarding the carrageenan moss pots – they might be pleasantly surprised, and you may make some converts – maybe keep them guessing about the “secret” ingredient.

    Hi Michelle – Those sea grapes seem to have captured everyone’s imagine – they just look so cool.

  31. Kenzie
    August 27, 2010 at 9:43 PM

    My favorite use for seawood is definitely in a sushi wrap.. particularly the shaggy dog. I’m happy to say that I have mastered these at home and can’t wait to try something a little more difficult! I love this article, so many great ideas…
    Deep Fryers

  32. admin
    August 29, 2010 at 12:09 PM

    Hi Kenzie, love the idea of a shaggy dog, glad you got good ideas, in researching this post, I was blown away at the versatility of this incredible product, and like you got a lot of good ideas.

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