Why are Hiroshima oysters so famous nationwide? Learn about the reasons and how they are grown.

Hiroshima is a suitable place for oyster farming

*This article is an excerpt from the YouTube channel of "Hiroshima Okonomiyaki Mitchan Sohonten [Official]".

"Hiroshima is a land that is suitable for oyster farming," says Miho Yudai of Kanawa Co., Ltd., which farms oysters in Hiroshima. Oysters grow in brackish waters where river water and sea water mix. Hiroshima Bay is an area rich in phytoplankton that flows from the Chugoku Mountains. In addition to being an area of water rich in nutrients, Hiroshima Bay is an enclosed sea area surrounded by many islands, which means that nutrient-rich water tends to remain there. The waves are also calm, and the tides are moderate, providing ideal conditions for oyster growth. For these reasons, Hiroshima has become a famous oyster production area.

Oyster farming procedure

Let's take a closer look at how oysters are farmed.

[1] Seedling collection

In time for oyster spawning, which takes place in May and June, scallop shells are dropped into the sea and oyster larvae are attached to them. This is the first step, called seedling collection.

[2] Suppression

In the second step, the harvested oyster larvae are transferred to the tidal flats and hung on shelves. The process is called "restraint," and involves setting up the shelves so that they emerge from the sea when the tide goes out. The aim is to grow strong oysters that are resistant to environmental changes by reducing the time they are submerged in seawater.

[3] Raft farming

After restraint, the shells with the oysters attached are removed and hung on oyster rafts, where the oysters are allowed to grow for about a year or more.

The difference between "for cooking" and "for eating raw"

The sea areas where oysters are grown differ between those for cooking and those for eating raw. Oysters grown in the sea areas near Hiroshima City, where domestic wastewater is relatively likely to flow into, are for cooking, while those grown offshore, where there is less domestic wastewater, are for eating raw. In fact, Hiroshima Prefecture is the only prefecture that separates oysters for cooking and those for eating raw based on the sea area.

*In Hiroshima Prefecture, in addition to the sea area restrictions, oyster businesses are also required to conduct inspections.

Does the size of the oyster affect the taste?

The taste of oysters does not change depending on their size. What's important is where they were grown, not their size. It's also a good idea to use different sizes of oysters depending on the cooking method. If you're using them for fried oysters or in a hotpot, we recommend larger oysters, and if you're eating them raw, such as in vinegar, we recommend smaller oysters.

The roots of Hiroshima oysters

How did "Hiroshima oysters" become known throughout the country?

"It's because there were people before us who branded Hiroshima oysters and supported them," says Xiaohei, who is familiar with the food and beverage industry in Hiroshima. Hiroshima has a long history of oyster farming, and it is said that it was first started in Kusatsu, Nishi-ku, Hiroshima City.

Oyster farming has changed over the years, including the "stone-scattering farming method," in which pebbles are laid out on the tidal flats and the oysters are allowed to attach to them and grow there, and the "crack-building farming method," in which bamboo or wood is erected on the tidal flats and the oysters are allowed to attach to them and grow there.

Why Hiroshima oysters are famous nationwide

Although it became possible to produce large quantities of oysters thanks to the development of farming techniques, it was still impossible to transport oysters long distances in a temperature-controlled environment like we have today. So, he came up with the idea of packing the landed oysters into bales filled with seawater, transporting them to Osaka, and selling and serving them on board the ship.

It is said that the origins of the "Oyster Boat" lie in the transportation of oysters to Osaka, which was the economic center of the time, and the people eating them on board the boat. This method was successful, and there were many oyster boats lined up along the rivers of Osaka at the time.

To transport to Osaka, it was necessary to select oysters that had strong vitality, so large oysters that were 2 to 3 years old were selected. Hiroshima oysters gained a reputation for being large and satisfying to eat, and the brand "Hiroshima is synonymous with oysters" was established.

Enjoy Hiroshima oysters, in season in winter, at Mitchan Souhonten!

In this article, we introduced the reason why Hiroshima oysters have spread throughout the country and how they are grown. Winter oysters store nutrients and have a rich, milky taste. The taste of oysters changes from autumn to winter and from the beginning of the year to spring! You can also taste raw Kanawa oysters at Mitchan Souhonten, so please come and try some winter oysters.

▶Click here for the YouTube video "Why is Hiroshima synonymous with oysters?"

▶Click here for the "Hiroshima Okonomiyaki Mitchan Sohonten [Official]" YouTube channel