The Okinawa Sea Salt Research Institute (Okinawa Kaien Kenkyusho) produces "Aguni no Shio" (Aguni Salt) on Aguni Island, using traditional, chemical-free methods to create a high-mineral sea salt. Established by Koshin Odo to revive Okinawa's traditional salt-making methods after Japan's nationwide salt field eradication in 1971 brought centuries of local production to an end. Rather than adopting industrial manufacturing, the company returned to the slow, chemical-free evaporation techniques that had been practised across the Ryukyu Islands for generations.
Based on the remote island of Aguni, northwest of Okinawa's main island, the institute draws seawater from one of Japan's least industrialised coastlines. With a small population and very little surrounding industry, the waters around Aguni remain exceptionally clean - resulting in a mineral content (about 15% of the salt, including magnesium and potassium) considered among the best in the world. Seawater is slowly concentrated through natural evaporation before being gently heated and crystallised over several weeks, preserving a broad spectrum of naturally occurring minerals that contribute to the salt's rounded character and complexity
Today, Aguni no Shio is regarded as one of Okinawa's benchmark traditional sea salts. Produced in relatively small quantities using time-intensive methods, it reflects a philosophy that values craftsmanship, patience and flavour over production speed, earning its place in both professional and home kitchens throughout Japan.
