Kelp tea

Kelp tea is a tea made from kelp.It is called konbu-cha  or kobu-cha  (昆布茶, meaning "Kombu-tea") in Japan, haidai-cha (海带茶) in China and dasima-cha (다시마차) in Korea.

Japan
In Japan, konbu-cha or kobu-cha is kelp tea made by pouring boiling water into chopped edible kelp (kombu) and leaching or pouring hot water into powdered kelp. 

Kelp tea for fortune
The tea served on New Year's Day and at weddings is sometime kelp tea  because the pronunciation of kombu is similar to that of the last part of "yoro kobu " (喜ぶ, meaning "be happy"). 

Fuku-cha(福茶, meaning "fortune tea") is sencha green tea with kelp, umeboshi, kuromame (black beans), and sanshō and is drunk on the last day of the year (Ōmisoka), in New Year, and on the day before the beginning of spring (Setsubun) in Kansai region, wishing a long life.

In particular, in New Year, oo-buku-cha or dai-buku-cha (大福茶, meaning "very good fortune tea"), which is sencha green tea with kelp and umeboshi, is drunk in Kansai region wishing good health and happiness.

Instant kelp tea
Powdery kelp tea is sold as an instant tea under the name of konbu-cha  or kobu-cha . It is made by drying kelp to a fine powder and blending it with seasonings such as salt and sugar . It's simply dissolved in hot water and enjoyed as a tea. Note that this type of konbu-cha does not contain any true tea (Camellia sinensis).

The powdery kelp tea was invented by the founder of GYOKUROEN "Umazou Fujita" in 1918.

Ume-konbu-cha  or ume-Kobu-cha, which is powdery kelp tea added freeze-dried crushed umeboshi, is also sold as an instant tea and is drunk as a tea in the same fashion.

History
Kelp tea is thought to have been drunk from quite a long time ago because "the Japanese have incorporated kelp and seaweed into their diets for 1,500 years".

It is said that, in 951, Kūya made a statue of the Ekādaśamukha to cure an epidemic that was spreading in the capital and went around the city giving oo-buku-cha to the sick.

Tea using kelp already existed in Edo period (1603-1868) at the latest, and people in these days drank it by pouring boiling water over chopped kelp.

Korea
Either dried kelp powder or julienned kelp can be used to make the tea.

Powdered tea can be made by pan-frying and pounding cleaned and dried kelp. For a cup of hot water, two to three spoons of kelp powder is used. Optionally, sugar or honey can be added.

Alternatively, around 30 g of cleaned kelp pieces are infused in 300-500 ml of hot water. The kelp slices are removed after infusing, and salt is added to taste.