Aging wine underwater was intended to boost the economy of the southwestern Japanese islands

A Tokyo company hopes aging wine in an underwater cellar off Amami-Oshima Island in Kagoshima Prefecture, southwestern Japan, will help revive the local economy.

Aging wine underwater is a common practice around the world because the conditions underwater – uniform and relatively cool temperatures, higher pressure and the absence of excessive light – are suitable for elegant wine aging.

Wine bottles are dumped in the Oshima Strait outside the city of Setouchi in Kagoshima Prefecture to allow them to mature on January 30, 2024. (Kyodo)

But the process is “rarely practiced in Japan,” said Yui Moritani, the 38-year-old president of a Tokyo public relations firm that launched the project.

At the end of January, about 500 bottles of European wine in stainless steel cages were lowered to the seabed at a depth of about 20 meters off the town of Setouchi in the southern part of the island.

The company opened a restaurant serving wine in the city in November.

Most of the bottles dipped in January remain in the sea until June to be delivered to customers in July. Some of them are aged longer to find the right ripening time for optimal taste.

The company also plans to offer an underwater aging service for wine bottles entrusted by customers in the future.

Moritani also hopes the project will improve the environment, with the underwater wine cellar serving as an artificial reef to attract fish and a bed of algae to absorb carbon dioxide.

Photo shows wine bottles in cages placed on the seabed in the Oshima Strait off the city of Setouchi, Kagoshima Prefecture, on January 30, 2024. (Photo courtesy of III Three Co.) (Kyodo)

A diver who helped sink the wine bottles said the water in the area was warmer than typical temperatures for aging wine, reaching 21C on Jan. 30, but there was an advantage in that wine can age quickly under such conditions.

“The biggest challenge is whether the wine will survive the summer in warm water,” Moritani said.