Have you ever eaten sushi? Did you know that a lot of sushi uses
seaweed as one of its ingredients? The green crunchy wrapping sometimes
used in sushi is called nori. Nori is made from seaweed - but it is not
in a fresh state. After the seaweed Prophyra is picked, it is immediately
dried into sheets. This was formerly done by sun-drying process, but this
job is now highly mechanized. The harvesters only take what they can
process in one day. Nori is first washed with freshwater than fed into a
shredding machine, which makes it to a piece 0.5x1 cm in size. The cut
nori is then thoroughly mixed with freshwater, 4 kg of nori per 100
The nori/water mixture is than fed into a machine that is almost like
a papermaking machine. In the machine it is put on top a wooden frame
about 30 sq cm on the outside, which is fit into mats of split bamboo
20x18 cm big. Then it's placed into a wire netting screen about 600 ml of
mixture is fed into each frame and the water drains away through the mats
and screen. The frames then move slowly across a production line and
afterwards it goes over a heated surface. The nori and the bamboo mats
are then moved going back in a circle for more nori-water mixture.
After the nori sheets are piled up and put into an oven to reduce the
moisture content to about 18%. This is in order to make a good product.
The temperature of the drying process is 500C. Than the bamboo mats are
then removed, the nori is than put together it 10s and packed in bundles
The nori is then shipped to a co-operative shipping point. There
they are carefully packed and sealed in cellopane so that the moisture
uptake is reduced as much as possible. Then they are shipped to all parts
of the world. The Japanese output is about seven billion sheets a year.
Korea produces 60-100 million sheets.