Special contribution: A trip to Atami to make dried fish

Yoichiro Sato, Director of Fujinokuni Museum of Global Environmental History

The Izu Peninsula was originally a volcanic island formed in the south. It moved north due to the movement of the Philippine Sea Plate and collided with Honshu about one million years ago. Volcanic activity continued after that, and as many as 100 volcanoes were formed. The collision of the Izu Peninsula caused land to rise on the Honshu side, and volcanic activity also began. Mount Hakone and Mount Fuji are still active today. The Hakone volcano, along with the Taga volcano and Usami volcano on the peninsula side, isolated eastern Izu from the Honshu side.

The Kano River originates from Mt. Amagi, a huge volcano formed almost in the center of the peninsula, slightly to the east, and creates the Tagata Plain in the northern part of the peninsula before flowing into Suruga Bay. The towns of Mishima and Numazu were built on the right bank of the Kano River, at the northern end of the plain, and have flourished as the center of Izu since ancient times. Mishima Taisha Shrine, said to have been founded in the Nara period, played a central role in politics and religion for the entire Izu Peninsula. Mishima is located at the western foot of Mt. Hakone, which separates the eastern part of Japan from Suruga. Since the 8th century, the Tokaido Road, which connects the eastern part of Japan (Kanto) with the areas west of Suruga, has passed through Hakone Pass in the southern part of Mt. Hakone and continues to Odawara. The Tokaido Road never passed through Atami. Even now, there is no good road from Mishima to Atami, except for the railway that passes through the Tanna Tunnel.
Nevertheless, the fact that Atami was in the same Izu province as Mishima is thought to have something to do with Shugendo. Murayama (Fujinomiya City), which was the base of Shugendo on Mount Fuji, is also said to have been part of the Hashitoyama domain of Atami and Izuyama, and it is said that there was a strong connection between Shugendo on Fuji and Shugendo in Izu.

Dried fish is a local specialty of Atami in Higashiizu. We had the opportunity to speak with Futami Hikaru, the fifth generation owner of Kamatsuru, a long-established dried fish store founded in the late Edo period in Atami. In order to popularize dried fish, Futami also offers a dried fish making experience. It is not just about cutting and drying the fish, but it starts from going to the market in the morning to buy the fish. In other words, this experience allows participants to learn the entire process, from obtaining the fish to actually eating it. The experience can be found in the middle of the city center along National Route 135, which runs along the coast.

According to Futami, dried fish developed in Atami as a way to preserve overcrowded fish. Among the animal-based foods used by the Japanese, most seafood is a natural resource, and it is difficult to estimate or control the amount of resources. When there is a poor catch, there is no catch at all, but when there is a good catch, there is a lot of it. Moreover, good catches and poor catches come without any warning. This is quite different from livestock and poultry, which are farmed animals and the amount of resources can be controlled to some extent. Therefore, there has long been a way to process and preserve overcrowded fish. There are still mackerel roads remaining throughout the country, where salted mackerel was transported mainly to inland areas. Sanma narezushi in the Kumano region of Mie Prefecture was also born from a similar story. Since the 1960s, people have had trouble disposing of overcrowded sanma, so they started making sanma narezushi instead of the sweetfish narezushi that they had been making up until then.

Now, let's talk about dried fish in Atami. Atami is one of the leading cities in the prefecture, if not in Japan, for dried fish. Dried fish is fish or meat that has been dried in the sun to improve its shelf life. There are several methods of preserving meat and fish that have been invented by humans, but the methods that remain in use in the Japanese archipelago today include drying, salting, fermenting, soaking in vinegar or honey, fumigation, refrigeration/freezing, and airtight storage. Dried fish is a preserved food made by combining "salting or soaking in soy sauce, mirin, etc." with "drying," and has probably been made and eaten for a long time.

We spoke to Futami-san, mentioned above. At Kamatsuru, they fillet and dry the fresh fish caught that day. It must have been the case everywhere in the past, but Kamatsuru still uses this method. There are many dried fish production areas around Izu. There are several stores in Atami, and Manazuru in Kanagawa Prefecture and Numazu in Nishiizu are famous nationwide for dried fish production. However, there are only a few places that use freshly caught fish to make dried fish. Most buy frozen fish and dry it for sale. It is probably more efficient to do so in order to produce large quantities stably.

We also had the chance to try making dried fish. First, we filleted the freshly caught fish and shaped it. The way to fillet it varies slightly depending on the type of fish, but for barracuda, the gills and innards are removed and the fish is split open along the back, leaving the head on. We split the head open using the same method as for alfonsino, a specialty of East Izu. For filefish and other fish, the head and innards are removed, the skin is removed, the fish is split open and the belly is shaped. Watching the craftsmen at work, the knife work looks rhythmic and simple, but in reality it is quite difficult.

The fish is then soaked in salt water with a concentration of 12-15%. The soaking time varies depending on the temperature of the day and the type of fish, but for filefish, 9-15 minutes is sufficient. In the past, the salt concentration was apparently higher, but recently, due to reduced salt intake, this concentration and soaking time has been settled on.
"When it comes to salt, there are products made using ion exchange membranes and local specialties called 'X-salt'. Which one is best?"
In response to this question, Futami laughed and said:
"When it comes to salt, it makes almost no difference what kind of salt you use. The key is to find the perfect balance."
The purpose of soaking in salt is to add saltiness, but the important part is apparently to remove the extracellular fluid from outside the cells of the fish flesh.

Once the shaping is complete, the fish is dried by placing it in a special dryer for an hour or two to remove the extracellular fluid. A temperature of around 1 degrees is sufficient. In the past, people thought of sun-dried fish as being dried, but it is said that there is almost no difference in taste between machine-dried and sun-dried fish.

Another preserved food similar to dried fish is "kusaya." It is made by opening up caught fish in the same way as dried fish, soaking it in "kusaya liquid" and then drying it. It is known for its strong flavor and strong smell. Kusaya liquid is a pickling liquid made by repeatedly using the same salt water used for dried fish, and is made from salt, umami components of fish, enzymes derived from fish, and microorganisms. In addition to its strong flavor, it is a unique pickling liquid for kusaya that is colored by the Maillard reaction and has a strong smell. Research is being conducted on the ingredients of kusaya liquid, but it seems that there are many areas that need to be awaited by further research. Kusaya is now considered a specialty of the Izu Islands, and according to Futami, there is one manufacturer in Ito City.

By the way, why did kusaya remain in the Izu Islands but hardly any remain on the peninsula side? I asked Futami about this.

"I think salt is a limiting factor. You might think that salt would be easy to come by on an island, but the salt production process uses a huge amount of firewood. On small islands, trees are cut down indiscriminately, so the firewood needed to produce salt quickly runs out."

There is also not enough water on the island. A bit off topic, but it is said that dehydration is the main cause of death for people lost at sea. The salt concentration of bodily fluids in the human body is 0.9 percent. Seawater, on the other hand, is about 3 percent. If you drink seawater because you are thirsty at sea, the osmotic pressure will cause your body to become even more dehydrated. Water is also a precious commodity on a small island. When trees are cut down on an island, the forest's water-retaining capacity is lost, leading to a water shortage. After salt, water is the next resource to become scarce on an island. Water was also a precious commodity on the island. Large amounts of water and salt are needed to make pickling liquid for dried fish. This is why people began to reuse pickling liquid. This leads to the hypothesis that this was kusaya liquid. Considering this, kusaya is a type of dried fish.

But why didn't Atami make narezushi? One reason may be that rice cannot be grown in Atami and other areas on the eastern coast of the Izu Peninsula. Kumano also has almost no plains, making it difficult to produce enough rice, but the large amount of sand carried by the Kumano River created an exceptional sandy beach in the northeastern part of the river mouth on the Kii Peninsula. The narrow plain that formed inside this beach likely made rice cultivation possible.

Interview cooperation

The photographer who accompanied us on the interview introduced the contents of the interview on his blog.
Please take a look at this as well.
The best time to eat and take pictures: "Itadakimasu" and "Gochisousama" taught by the "Himono-making experience"

Written by: Yoichiro Sato
Photo: Yoshihiko Konan