The Hidden Potential of Oysters

There is a dry, clanking sound resonating through the work area. I can see the backs of women lined up, and in front of them are mountains of oysters. These women, called uchiko-san (“strikers”), remove the oyster meat from the shells with a surprisingly fast technique. This work is called kaki-uchi, or oyster striking. It is said that these skillful women remove 80 kg of meat in one day.

The Sound of Kaki-uchi Pronouncing Winter’s Morn

Kohei Kawasaki of Kunihiro Inc., a company which has processed and sold oysters in Hiroshima since 1957, tells us that, “The sound of kaki-uchi is something that reminds us of winter in Hiroshima. A clanking sound is made when opening in the shells are made. Instead of a knife, in Hiroshima we use a special tool just for kaki-uchi. I remember when I was younger, you could hear this sound across town on winter mornings.”

Eating Shucked Oysters in Hiroshima

Oysters are a winter delicacy in Japan. With piping hot oyster hot pot, grilled oysters, and raw oysters, the joy never ends. Hiroshima is the largest producer of oysters, accounting for more than 60% of all domestic shipments. Mr. Kawasaki tells us that a distinctive feature of Hiroshima’s oyster culture is the way of eating oysters after they have been removed from their shells.

“Hiroshima has the largest amount of domestic shipments of shucked oysters at 19,000 tons. There is a big gap between Hiroshima and the second largest, Okayama, at 3,000 tons. For shucked oysters, the oysters must be quite meaty so they can stand alone without support from the shells. Hiroshima has the right sea conditions to grow oysters with good meat.”

He goes on. “How many oysters do you eat per month? Most people probably only eat a handful, even if they eat them every month. Nowadays, the style of eating oysters in their shells purchased one by one at oyster bars, etc., is becoming popular. But originally, there was a culture of eating oysters that have been removed from their shells both for Hiroshima residents and across Japan. In Hiroshima, families buy them by the kilogram, and they are generally eaten in hotpots, etc. Oysters are full of nutrients, including ample amounts of zinc and taurine. I want to get back to a culture of eating oysters on a regular basis.”

People from the Jomon Period People Also Ate Oysters

The history of oysters in Japan is long, and it is said that oysters were already being eaten during the Jomon Period (ca. 14,000 to 1,000 BC). As proof of this, many of the remains of shell mounds that exist all over Japan from prehistoric eras contain oyster shells. Oyster cultivation began in the Muromachi Period (1336 to 1573), and there are records stating that a cultivation method was discovered in what is now western Hiroshima during the Tenbun Era (1532 to 1555). Since then, Hiroshima has continued to be a famous place for producing oysters.

The Sea of Hiroshima, Full of Nutrients

Oysters have been adored in Japan since ancient times. So why has Hiroshima become the main region for production of oysters in Japan? Mr. Yamasaki tells us that it is because the waters here are especially calm among the Seto Inland Sea. “The nutrient-rich waters of the Ota River flow into the sea, and the waters around Hiroshima are particularly calm among the waters of the Seto Inland Sea. As a result, plankton reside here, allowing us to raise delicious oysters filled with nutrients.”

Another feature of Hiroshima oysters are the safety measures. Normally, it is standard to ship caught oysters after washing them, but Hiroshima oysters are required to be purified over the course of a day in dedicated pools. By making the oysters expel the contaminants held in their body and guaranteeing safety, even the oyster’s characteristic astringent taste is removed. “Oysters take in more than 10 liters of water every hour, filter it through their gills, and store nutrients from the ocean water in large quantities. At the same time, they also store bacteria, etc., from the ocean in their bodies.”

An Environmentally-Safe Future Source of Protein

The oyster’s powerful filtration process can also functionable as an ocean water purifier. It is well known that the water quality of the oceans where oysters live are improved. In Tokyo Bay, experiments are being carried out to purify the water through oysters naturally live there. Oyster shells themselves also have a purification process, and attention has been drawn to the potential of oysters, as the shells can improve the environment as a material in agricultural fertilizers, tetrapod structures, etc.

“It is thought that oysters have great value in being used as a protein source. Oysters have a small impact on the environment when compared to beef and other main sources of protein, and they also purify the ocean. They can be raised anywhere with an ocean, and even compared to insects and other alternative protein sources, they have been a familiar food ingredient for a long time across the world. The potential of oysters ought to become even more important as the issues of environmental destruction and climate change become more of an issue across the globe.”

Grilled Oysters at an Oyster Shack

The popping sound resonating throughout the oyster shack is the sound of oysters bursting open while grilling on a charcoal fire. We visit Milky Tetsuo no Kaki Yatai’s Ujina Store next. This is a shop selling grilled oysters along the Hiroshima coast in an area called Oyster Road where many oyster restaurants are located. Here, customers can enjoy eating oysters with hamayaki (grilling freshly caught seafood near the beach) style after the customers themselves have grilled the oysters.

Mr. Imamura, the sales manager for the company that runs this shop, tells us that, “Recently, eating grilled oysters is gaining popularity as the conventional way to eat them in Hiroshima. The customer picks out the oysters or other shellfish they like, take them to their seats, and grill them on their own. A type of oyster called sanbaitai, which is larger than normal oysters, is especially popular here. It is very rich, with lots of umami. As I said, grilled oysters are especially popular, but we also offer other items, such as oyster rice and oyster soup.”

The Only Oyster Bar in Fukuyama

Oyster bars are a part of oyster culture that cannot be overlooked when talking about eating oysters. We visited with Daisuke Koga, who runs Forever Cafe & Oyster Bar in Fukuyama City. At this bar, customers can enjoy raw oysters, fried oysters, grilled oysters, and a variety of other ways to cook oysters from around the world together with alcohol. Incidentally, the oysters used here are ones Kunihiro mentioned at the beginning of this article. First, let’s take a look at Mr. Koga’s oyster dishes.

Scotch and Raw Oysters

Scotch whiskey is poured over raw oysters and the oysters are moved around so as not to spill any of the scotch. In Supposing My Words Are Whiskey, an essay by Haruki Murakami, there is a scene that takes place on Islay, where oysters are eaten after scotch is poured over them. Mr. Koga tells us that, “Bowmore is an alcohol that is made at an oceanside distillery. Since oysters are also from the sea, they go well together.”

White Fried Oysters

The secret to the white coating is to fry the panko bread crumbs developed for fried oysters at a low temperature in lard. This locks in the umami of the oysters while also preserving their moisture. This makes fried oysters, with their working class image, into a special meal.

Oyster Unihoren

“Unihoren (“sea urchin and spinach”) is a second-rate Hiroshima specialty, but I added oysters to this dish.” Sea urchin, spinach, and oysters are grilled on a griddle, and eaten with slices of a baguette.

“If you look abroad, you can see that there are many ways to enjoy oysters. In America, there are oyster bars in most towns, and everyone eats them by the dozen. In the southern parts of America, eating oysters in a sandwich called a Po’ Boy is common. There is even a unique food culture for oysters in Europe. But most of the oyster food in Hiroshima is from grilled oyster shops. Before this bar, there wasn’t even a single oyster bar in Fukuyama. Of course, the culture of Japanese oyster cuisine is excellent. But, it’s good to have a place offering new ways to eat oysters alongside the traditional ways. I want to offer globally-accepted foods, especially because Hiroshima is a place for oysters. There is still room for development in Hiroshima’s oyster culture.”