Nov 08,2018
Kusaya — salted, fermented, and dried fish noted for its pungency — is just as popular on Izu Ohshima as ever. It is sold alongside other types of dried fish in local supermarkets and is commonly eaten at set-meal restaurants and izakaya pubs. In the second installment of this series, we explore the secrets behind how kusaya’s uniquely pronounced aroma and flavor are produced.
Kusaya is a type of traditional dried fish found in the Izu Islands. What sets it apart is how it is soaked in kusaya eki pickling brine before being dried. Etymologically speaking, some say that kusaya comes from the word kusai, meaning smelly, combined with ya, an exclamation. Thus, the reaction that “Oh, this is very smelly” is embedded in the very name. Thinking about kusaya in this way, you cannot help but feel a sense of endearment toward it.
In the Edo period (1603 to 1868), kusaya was a very popular but hard-to-find delicacy. Tales of kusaya often appear in rakugo (traditional Japanese comic storytelling) and remains popular trope among rakugo performers to this day. The late master rakugo performer Tatekawa Danshi even had a legendary anecdote about enjoying kusaya with a drink on a plane. Though it has its quirks, once you try it, you can’t forget it — that’s the uncanny allure of kusaya.
Lifting soaked kusaya from the kusaya eki, which must be handled with great care
We arrived at Marui Suisan, located at Izu Ohshima’s Habu Port, at around 7:30 in the morning. Work was already underway, which we were told would consist of lifting out the amberstripe scad that had been soaking in the kusaya eki from the previous day, rinsing them, and drying them. On observing the processing, we realized quickly that the work was different from what we had imagined.
To be honest, we had imagined that handling the fish would involve lots of splashing water and everyone working at a mad pace. In reality, the workplace was very quiet, with everyone moving with great care and precision.
Without much thought, we commented casually on how deliberately everyone went about their work. Nemoto, an eight-year veteran kusaya worker with a calm demeanor, suddenly grew tense as he retorted: “We work this way because we can’t afford to spill any of the kusaya eki.”
The fish are removed from the kusaya eki with a net and carefully placed in bamboo baskets placed over the tank so that the dripping kusaya eki returns to the tank. After this, the baskets containing the fish are set on tubs that carefully collect every drop of kusaya eki that continues to drip from the fish. Not a single drop of kusaya eki reaches the floor, as the work continues in silent concentration.
Marui Suisan has been producing kusaya on Izu Ohshima for around 300 years. Our guide is Okuyama Kenichi, the fourth-generation owner who has dedicated 38 years of his life to kusaya. He says that he was rigorously trained in every aspect of the craft — from selecting the right fish to mastering the secret salt concentration and managing the precise temperature controls.
Okuyama Kenichi, the fourth-generation owner of Marui Suisan
“In the old days, both salt and water were precious commodities on Izu Ohshima. This meant that people couldn’t simply throw out the saltwater when producing dried fish. By adding more salt, little by little, to saltwater that had already been used to soak fish and repeating the soaking process again and again, the liquid fermented and turned into kusaya eki.”
Even on Ohshima, which is surrounded by the sea, producing salt was extremely difficult because of the frequent rain.
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Oshima Ocean Salt: Natural Salt Crafted by Sea and Wind
Furthermore, Izu Ohshima lacks fertile land for crops, so rice cannot be grown on the island. And there was a period where the islanders had to pay land taxes in salt, meaning only a meagre amount of salt was freely available for use by the islanders. Kusaya came about precisely because of the island’s geography and history.
“For ages, people on this island have said that a drop of kusaya is a drop of blood.”
The weight of Okuyama’s words shows up in every aspect of their operations. Not a single drop of kusaya eki from the soaked fish is wasted. Even when rinsing the soaked fish, the water from the first rinse, which contains a lot of kusaya eki, is kept and reused. You get a palpable sense how incredibly important kusaya eki is just by being in the room. For instance, if a worker is even a little sloppy when handling the fish, the worker is likely to get yelled at.
Bamboo baskets are essential for thoroughly rinsing the fish without them slipping around
Marui Suisan’s kusaya eki has a gooey chocolate brown color
In former times on the Izu Islands, kusaya eki was included in a bride’s trousseau. Much like the old saying that the taste of her nukazuke pickles is a measure of a bride’s talent, on the Izu Islands, the taste of her kusaya was said to be a reflection of a bride’s skills. Undoubtedly, each family took great pride in the kusaya they prepared.
Kusaya is made with amberstripe scad, mackerel scad, flying fish, and other varieties caught in nearby waters. The skilled workers can fillet a fish in just 10 seconds, an astonishing speed. They have perfected this skill because the freshness of the fish is paramount.
At Marui Suisan, only Okuyama, the fourth-generation owner, is permitted to make adjustments to the kusaya eki. The kusaya eki, which is alive and breathing, is normally stored in an underground tank to maintain its quality. When fish arrive, the kusaya eki is pumped up from the tank and its temperature and salt concentration are adjusted for the weather conditions and the type of fish to be pickled. And it is no surprise that natural salt produced on Izu Ohshima, with its mellow flavor, is used in the kusaya eki. Okuyama adjusts the salt concentration with his own special technique (which is a closely guarded secret).
“Kusaya eki is alive, you know. So we have to stir it and maintain it every day, even when there is no work. Plus, the kusaya eki we used today gets tired and needs to rest. This point is really important because kusaya eki is very delicate. If you slack off, you will know right away because of the smell. But when you make the effort to take care of it, it will respond and be delicious,” says Okuyama. His apprentice Nemoto adds: “If we don’t thoroughly mix the kusaya eki, we will definitely get told off later.”
Each fish is placed in the kusaya eki so they don’t overlap. Every step of the process is done with great care and attention.
After some time, the kusaya eki begins bubbling vigorously, a sign that it is breathing
Contrary to popular belief, kusaya eki is not made by fermenting fish innards, salt, and water. Rather, water, salt, and components that come from the fish and blend together and then ferment for decades or even centuries to produce the kusaya eki’s umami flavor. The brine is populated with countless fermenting bacteria that have survived for generations.
Okuyama tells us: “In the old days, kusaya eki was used as an alternative medicine. People would drink a small cupful as a remedy for stomachaches or apply it to wounds as a disinfectant.” But since the brine is used to make dried fish, surely it is very salty, which would sting unbearably if applied to an open wound? With some nervousness, we asked if we could taste a little of the kusaya eki. “Of course. Go ahead.”
We took a tiny sip of the kusaya eki from a barrel. Oddly, it was not salty. Its aroma was mild and a surprisingly mellow umami spread across the tongue.
This made us curious. Why doesn’t the liquid go off at such a low salt concentration? And how can it have medicinal properties? After some research, we discovered that kusaya eki is teeming with powerful natural antibiotics. Researchers at the Tokyo University of Marine Science and Technology and other institutions have shown that the so-called kusaya bacteria and other microorganisms in kusaya eki produce antibiotics to protect themselves and eliminate putrefying bacteria. The natural antibiotics produced by the bacteria are safe for human consumption and are broken down in the body, so no antibiotic resistance develops.
So calling kusaya eki medicine is not just some folklore or superstition. In former times when remote islands like Izu Ohshima lacked modern healthcare facilities, the islanders’ ancestors likely came to rely on the benefits of kusaya eki through empirical knowledge.
Kusaya is delicious when hot off the grill. The aroma stimulates the nostrils and the umami spreads with each bite. It’s an irresistible combination.
As our tour of the kusaya production process was coming to an end, Okuyama’s wife called out to us. “So how was the smell? You said this was your first time touring the plant.” We took a deep breath after being called out, but answered that it didn’t smell bad at all. Perhaps we had gotten used to it. On hearing this, Okuyama shared an interesting story.
“We had a class of American schoolkids visit us. And only a few said that the kusaya smelled bad. Most said that it smelled like cheese.”
Both kusaya and cheese are from the same family of fermented foods. It’s likely that the kids, free of any preconceived notions, spotted the commonalities between cheese and kusaya. Just as anchovies, a fermented preserve often found in Italian cuisine, go well with cheese, kusaya and cheese are an amazing pairing. Take a small bite, sip some saké, and you’ll find yourself in an endless loop.
The people of Edo (now Tokyo) called kusaya the flowers of Edo, perhaps because the smell was so distinctive. The aesthete Edoites were likely captivated by the vibrant and aromatic smell of grilled kusaya.
The rinsed kusaya are beautifully arranged on drying nets by workers whose hands move with gracefully flowing motions. Even as they chat away, their hands never stop moving.
In our modern times, people tend to be drawn to things our eyes desire or things we conceive of in our minds. The kusaya we encountered on Izu Ohshima served to inform us instinctively of what is good for the body and what is delicious. Kusaya eki is a treasure, carefully nurtured and preserved thanks to the geography, history, and culinary wisdom of Ohshima. We hope, without reservation, that it will continue to be passed on for generations to come.
＊Products are available for purchase via the email address listed on their website. In-store purchases are also available (please inquire beforehand).
●Getting to Izu Ohshima
Getting to Izu Ohshima takes an hour and 45 minutes by high-speed jet ferry or six hours by overnight ferry from Tokyo’s Takeshiba Sanbashi Pier. There are also ferry services from Kurihama Port in Kanagawa and Atami Port and Ito Port in Shizuoka.
Contact Tokai Kisen at 03-5472-9999 or 0570-005710
URL：https://www.tokaikisen.co.jp/
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