Japanese Soul Food: The Unknown World of Seaweed

The early morning ocean, reflects the orange of the rising sun. The captain operates the steering wheel using both hands. When the two arms that extend from the ship reach the surface of the water, a large, black, curtain-like net appears from under the water. The boat is then covered under the jet black nori (a type of seaweed).

The black seaweed falls onto the deck like a heavy rain from the net that passes over the ship. This is a glimpse into the harvesting of nori on a fishing ship, known as a moguri-bune (“diving ship”). Perhaps many people do not know it is harvested in this way.

Eating freshly steamed rice with nori is a truly Japanese breakfast. A vital part of sushi, it is an essential ingredient in Japanese food, used to wrap rice cakes that are grilled to make isobe-yaki and added into miso soup. Let’s take a look at the world of nori, with Hiroshima taking center stage.

Southern Fukuyama City, in Hiroshima Prefecture. The inland waters in this area are known as a prominent place for seaweed production in the Seto Inland Sea. We visited with Toshinobu Kaneda, a representative from Maruko Suisan, a company that produces nori in these waters. “We raise the seaweed from spores, and handle everything ourselves, from cultivation to harvesting, processing, and selling. I don’t think there are many companies in Japan that handle everything like we do.” Let’s first take a look at the process of creating the seaweed.

Breeding (Start of October)

This is the process of attaching oyster spores (seeds) to the nets. The conditions are adjusted by lowering the temperature of the water through rotating the water wheel and creating a current, thus making it easier to release the spores. The seaweed spores are approximately 20 microns in size. Checking the spores with a microscope is an elaborate job.

Raising the Seedlings (End of October through Middle of November)

When the water temperature falls to 23 degrees Celsius, the nets with spores attached are placed in the cultivation area. The seedlings are raised by repeating the process of washing and drying the nets. To prevent other marine flora from attaching to the nets, the rise and fall of the tides near the tidal flats where nori naturally grows is artificially recreated above the water.

Honbari (End of November through Beginning of December)

When the water temperature falls to 18 degrees Celsius, the nets with the attached seedlings are put back in to the sea.

Harvesting (Middle of December through March)

The nori is harvested while passing under the nets on a boat known as a moguri-bune (“diving ship”). The first seaweed harvested each year is known as Ichiban Nori (“First Batch of Seaweed”), and it is the most delicious. The nori is cultivated again in a 17 to 18 day cycle, and the second and third batch are harvested.

Factory Work

During the harvest season, the factory operates 24 hours a day. The seaweed is mixed with water, set into a square shape, and dried to create the familiar nori. Mr. Kaneda says that, “The flavor of the nori is determined by how good or bad the water is and the way it was raised in the open sea. Generally speaking those are the two main elements.”

Delicious Ways to Eat Nori

Mr. Kaneda’s dried nori is simply dried seaweed made through a simple process, without any added salt or flavoring. “It’s the most delicious when you eat it after roasting.” He toasts it lightly in an oven toaster. The crisp texture is paired with the aroma of the beach and a natural saltiness. There is also a rich marine umami. “The salt is just what was already in the seaweed. It’s different from the other stuff, right?”

Hakozaki-maki, a Meal for Seaweed Farmers

Local seaweed farmers eat nori as Hakozaki-maki (“Hakozaki Roll”). It’s easy to make. Rice is added to salted and roasted nori, the desired fillings are added, and it is completed by rolling it up. “Today I made one with tuna and mayonnaise, and one with cucumbers and crab sticks. It’s a kind of sushi roll you can eat with one hand while on deck.”

Two Sheets a Day Keep the Doctor Away

Nori is attracting attention for its health aspects. It has many great health benefits, so much so that there is a saying that, when translated, means, “two sheets a day keep the doctor away”. It’s high in protein, low in calories, and includes folic acid, nori peptides, vitamins, and minerals. We’re told that Mr. Kaneda received a letter of gratitude from a customer who ate his seaweed, saying, “My hair turned black and I regained my youth”.

The History of Hiroshima Nori

Fukuyama has been a place of nori production since ancient times. We are told that in the past, production was even more popular than it is today across all of Hiroshima Prefecture. As a heritage of this, Hiroshima Prefecture is still a region in Japan that is prominent for its collection of seaweed wholesalers.

“We say that in the past, nori was cultivated using the variations of the rise and fall of the tides on tidal flats. But as tidal flats were ruined through industrialization, cultivation areas were lost, and the number of people producing seaweed decreased. Around 1965, the current floating-sinking method was born, and it became possible to cultivate nori in places other than tidal flats”

“There are many aspects of nori ecology that haven’t yet been investigated, and cultivation technologies continue to improve independently to this day. Harvesting is determined by monitoring the conditions and I repeat a trial and error process every day, as the elements that rely on the power of nature play a major role in production. I will research how to steadily make the nori that I produce more delicious until I die.”

The Best Nori in the Inland Sea: One Bite and You’re Hooked

Mr. Kaneda’s persistence is recognized by the chefs of Fukuyama. Shun’ichi Hirakawa is a manager of Shu’s Fukuyama Tenmaya shop, offering onigiri (“rice balls”) made using Mr. Kaneda’s seaweed. He says that, “Mr. Kaneda’s nori is completely different from other seaweed.” This shop uses Mr. Kaneda’s Ichiban Nori for their rice balls.

“Because onigiri is a very simple food, made by combining rice, nori, and other ingredients, I want to be particular about the flavor of the seaweed. Mr. Kaneda’s nori is outstandingly delicious. The flavor is so different that once you try it, you won’t be able to go back to other brands. Here, try some. You’ll surely be able to tell the difference from other onigiris.”

As a side note, Mr. Kaneda told us that the way to tell if nori is delicious or not is to look for a “deep black color and a shiny surface”. When toasted, look for a dark, almost-black green color, and when untoasted, a slightly red color among the black is a sign of its flavor. Be on the lookout for delicious nori seaweed using these techniques.