Laver (Porphyra tenera) is a seaweed also known as “hae tae” (海苔). It grows on the rocks in the sea like moss. It grows to approximately 14-25 cm in length and 5-12 cm in width, and has a long, oval shape with wrinkles along the edges. The upper part of the laver plant is reddish brown and the bottom part is green and blue. Laver grows beginning around October, breeds from winter to spring, and then disappears in the summer. It can be found in the waters surrounding Korea (Jeju, South and West coasts), Japan and China.
Laver has long been cultivated to meet demand not satisfied by harvesting naturally occurring laver. For cultivation, field collection equipment is installed in the sea in autumn for seeds to attach to. In South Korea, the laver is cultivated along the coasts of South Jelloa and Gyeongsang provinces. In particular, cultivation in Wando (South Jelloa) province is very famous. There are two cultivation methods: Racks (the traditional method), and floating rafts (the method used for mass production).
In racks type cultivation, floating “pakak” (laver seed) needs a net to cling to. Starting in the spring and summer, nets are prepared for cultivating the laver. First, bamboo sticks are planted in the seabed by hand over several months. Once the bamboo sticks are in place then net is fixed to the bamboo. Several nets may be connected together. “Chaemu” (planting seeds on the net) is done in September. After installing the net, a process called “bunmang” may be used to help the laver seed stick to the nets. Bunmang means that the nets are prepared in multiple layers, as opposed to a single layer, so that laver seeds are more likely to stick to the net. Once seeds have stuck to the net, the nets should be separated and re-installed. The separated nets are first connected in a straight line in a working place in the sea and then moved to a farming area where they are re-installed. This entire process is carried out by hand.
After installation at the laver farm, Racks type nets are submerged during high tide and are exposed to the sun at low tide, allowing for a certain amount of photosynthesis to occur so as to maintain laver’s original flavor. Racks type laver cultivation is an eco-friendly farming method. Naturally growing laver is relatively scarce and insufficient to meet market demand, thus most of laver is provided through cultivation. Racks type laver is very similar in quality to naturally occurring laver, and has a good taste.
Most of the historical knowledge related to laver cultivation has been handed down by word of mouth. Its cultivation was reported to have started at the mouth of Seomjin river, in the Wando and Joyakdo areas (South Jelloa province). Laver cultivation started around 400 years ago and was initially only possible in the ocean around the southern part of Korea. However, due to rising ocean temperatures, cultivation became possible further north, and has spread to the Chungcheong area (central Korea). Racks type laver is produced in some areas of Wando, Shinan, Kangjin and Jangheong, however fewer than 100 farms across the country use the racks method.
Production of racks-type laver is very low and the price is relatively expensive as compared to that of mass produced laver. Therefore, racks laver is only sold in small amounts at department stores. This traditional method faces competition from laver grown using the mass production “floating rafts” method. Due to high production costs, low cultivation quantity, and increasing water temperature caused by global warming, racks laver production is declining. The number of producers of racks type laver is also declining due to aging fishing village populations.