Table of content A-Z




Synonyme: Tang, Seetang, Alge

englisch: seaweed


Algae have been common since the beginning of life on earth. They have served as an important food for inhabitants of coastal areas for many thousands of years. Even today, they are very popular as a food in Japan and China; currently, Japan has the highest consumption per person per year.

Outside of the Asian region, algae became less important, but in the past few years their significance has increased again. Today, the USA and Great Britain are among the top consumers. Meanwhile, algae are also cultivated off the coast of France. Particularly there, and in Ireland, several varieties of algae are in great demand as culinary specialities.


The wave of growing popularity is only slowly reaching Germany. Algae are hardly used here at all, except for the preparation of sushi. They are occasionally found only in delicatessen shops, organic food markets, and Asian shops and in the delicatessen departments of well-assorted supermarkets. They are sold dried.

Appearance, taste, characteristics

A relatively small portion of the several thousand known varieties of algae are used in the human diet. They are classified according to the pigments that they contain in addition to the green pigment chlorophyll. There are green algae, red algae, brown algae (kelp) and blue algae. Blue algae have no relevance as a food.

The species differ in form, appearance, physiology and area of cultivation. Some algae grow preferentially in polar seas or on snow-fields, others in hot springs; some prefer stagnant, others flowing water. Either they grow on objects or they swim around freely.

For cultivation, nets are inoculated with young algae. Sprouts are wound around the individual lines of the nets, and the nets are then laid out in shallow water and attached to buoys. When the algae have finished growing they can be harvested by hand or by machine.

Several varieties of algae are presented here:

* Aonori (Monostroma)

This alga is produced chiefly in Japan. It belongs to the green algae and is used fresh as a salad.

* Arame (Eisenia bicyclis)

Arame is a brown alga that grows in the Pacific. It is cut in thin strips and sold pre-cooked. It must be soaked prior to preparation. In contrast to other varieties of algae, because of its mild aroma, arame can lend a pleasant flavour to prepared foods. It doesn't have the typical aroma of the sea, but rather a sweet character owing to its mannitol content. It is popular as a salad and in mixed vegetables.

* Dulse / dillisk (Palmaria palmata)

The red alga dulse, native to the Atlantic, grows preferentially on stones and mussels in the cold water of the tidal zones. It is cultivated chiefly in Great Britain, Canada, the USA and some Mediterranean countries. It has been eaten for centuries in Ireland and Brittany. It is suited for the production of seasonings as well as for soups, salads and mixed vegetables. After it has been soaked for a short time it does not needs to be cooked.

* Hijiki / hiziki (Hizikia fusiforme)

Hijiki belongs to the brown algae. It is black, with a shiny surface, and has thick pulp that is firm to the bite. It has been a fixed ingredient in the Japanese diet for centuries. It is there, and in North and South Korea, that the alga is mainly cultivated and used. The hijiki can be used fresh or dried, for soups and stews, as a side vegetable and a salad ingredient. The dried algae must be soaked for some time before it is eaten. Hijiki algae have a slightly sweet and nutty taste.

* Irish moss (Chondrus crispus)

This red alga, which thrives in the cool North Atlantic, has a long tradition, not only in the Irish cuisine but also in other European countries. However, it is not used as a vegetable, but rather because of its thickening effect in boiling water. This effect is due to its carrageenan content. Thus Irish moss is used, among other things, to prepare flummeries or blancmange.

* Kombu (Laminaria japonica)

The kombu alga is also known as kelp and belongs to the brown algae. Japan, China, North and South Korea, and the area of the former Soviet Union are among the producers. A traditional soup, dashi, is prepared from kombu algae. They can be deep-fried, and can thus be processed as spicy chips. Ground kombu serves as a seasoning in place of salt. In Germany, the alga can be bought in the form of bath-water additives. For a long time, owing to its particularly high iodine content, kombu was not approved to be sold as a food.

* Sea lettuce (Ulva lactua)

Freely floating in water or growing on stones, this green alga, also known as green laver, grows best in shallow water near the coast and in brackish water that is especially rich in nutrients. It is particularly common in France. It is sold fresh and dried, and is used for salads, soups and hearty baked goods, and also for marinating fish.

* Mozuku (Cladosiphon okamuranus)

This brown alga is harvested exclusively as a naturally growing crop in the tropical climate of southern Japan. It grows there in calm, shallow water. It is eaten fresh with soy sauce or as a salad. Prior to consumption, it is rinsed thoroughly to remove the salty taste.

* Nori (Porphyra tenera)

The nori alga is the best know variety in Germany. It is used as a wrapper for sushi rolls. It has been cultivated on Japan's coasts for centuries and is popular as a salad and as a garnish for soups and stews; it is used for desserts and rice dishes and as a seasoning. Nori leaves are the best-known nori product sold here. To make them, the algae are minced, pressed and dried, and then roasted. It is not necessary to soak the leaves before eating them.

* Ogonori (Gracilaria spp.)

For several centuries, these algae have been eaten as a salad vegetable on Hawaii. The Gracilaria species is a good source of agar.

* Sarumen (Alaria esculenta)

This brown alga grows in the waters of the North Atlantic and is also cultivated and used in Japan. It grows best in water with a strong current below the tidal zone. Its uses are similar to those of the nori alga.

* Sea grape / green caviar (Caulerpa lentillifera)

This green alga takes its name from its grapelike appearance. It grows best on the sandy and muddy bottom in shallow water and is sensitive to fluctuations in salt content. The fresh algae are used in salads.

* Wakame (Undaria pinnatifida)

This alga is native to Japan and East Asia. Meanwhile, it is also successfully cultivated in Brittany. Like the sarumen, the brown alga grows below the tidal zone in water with a strong current. It can be used as a seasoning, to garnish soups and stews, as a side vegetable or salad, and processed as chips.


Algae are one of the foods with the highest iodine content; red algae contain less iodine than brown algae. Some varieties can also contribute to a better supply of omega-3 fatty acids.

100 g contain:

Algae, fresh
Energy (kcal)
Water (g)
Protein (g)
Fat (g)
< 1
Carbohydrates (g)
Fibre (g)
Vitamin A (RÄ) (μg)
Vitamin B1 (μg)
Vitamin B2 (μg)
Vitamin B12 (μg)
Potassium (mg)
Calcium (mg)
Magnesium (mg)
Iron (mg)
Zinc (mg)
Copper (mg)
Manganese (mg)
Iodine (μg)

Harmful substances

Algae that grow in polluted water can be strongly contaminated with heavy metals, among other things.

Quality criteria, optimal storage conditions

Algae found on the market here are sold mainly dried. In this form they can be stored for a long period. Keep them in a cool, dark and dry place.

In France a process has been developed that keeps algae fresh for up to 6 months. To this end the algae are salted and lose some of their weight. The salt acts as a preservative. The consumer can return the algae to their original weight again by rinsing them for 10–15 minutes under running water.

The origin of algae and their possible contamination with heavy metals are the subject of much discussion. For instance, the USA stopped the import of Japanese algae because of its high contamination with mercury.

You should buy algae from trustworthy producers who provide adequate information on the packaging about the goods and their origin.

Presumed effect on health

All brown algae contain alginic acid, which supports the body in removing heavy metals and radioactive substances.

For many centuries algae have been used in traditional Chinese medicine. Arame and hijiki, for instance, are supposed to help in strengthening skin, hair and nails.

Medical and pharmaceutical research is also currently being done on the effect of algae. Numerous positive effects have been proven: They are said to purify the blood and reduce blood pressure, to be antiviral, antibacterial, anticarcinogenic and to protect the stomach and the intestines.

Form of consumption, use, processing, practical tips for preparation

The different varieties of algae have different uses. They are suited for salads and soups and as vegetables. Some can be deep-fried and others can be used as a seasoning. Many dried algae must be soaked prior to consumption, others cooked, and still others can be eaten dried. The correct method of preparation is given on the packaging.

Wakame is recommended for producing a seasoning and a salt substitute from algae. Bake it in the oven at 200°C for 10–15 minutes until it is crisp. If you grind it, you have a powder with which you can season vegetable dishes, soups and cereal dishes.

Arame and wakame contain natural glutaminic acid, which acts as a flavour enhancer and tenderizer. Soak one of the two types of algae in water along with beans, peas or lentils and cook them as a stew. The legumes will be more tender and the dish more easily digestible, thanks to the glutaminic acid. You can also mix the tender legumes and algae with a small amount of water to make a spread, dip or pâté.

In the food industry, red algae in particular are used to make gelling or thickening agents such as agar, carrageenan and alginate.





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