Aasa-jiru is a traditional Okinawan soup made with aasa, a green seaweed known as hitoegusa, and Okinawan island tofu. The seaweed grows naturally around rocky coastal areas and is also known as aosa or aosa-nori in other parts of Japan.
Seasoned simply with salt and soy sauce, aasa-jiru has a remarkably light and refreshing flavor. While many Okinawan dishes are known for their rich and hearty seasonings, this clear soup offers a delicate contrast. With every spoonful, the gentle aroma of the sea comes through, evoking Okinawa’s beautiful coastline.
Aasa-jiru is often served as part of a set meal or alongside everyday dishes at home. It can also be prepared as a miso soup, and tofu is a particularly common addition.
Because of its simple preparation and familiar flavor, aasa-jiru is often described as a classic Okinawan home-style dish. It is especially enjoyable in the morning, when its clean flavor makes a refreshing start to the day.
The soup is traditionally prepared by adding chopped tofu and aasa to a broth made from fish, then seasoning it with salt, soy sauce or miso. The result is a simple soup in which the delicate flavor and fragrance of the seaweed remain at the forefront.
In the Yaeyama Islands, a similar preparation is known as Yukuzuru and may also be served on special occasions, showing how deeply aasa has become connected with local food traditions throughout Okinawa.
In Okinawa, several types of green algae, including hitoegusa, aosa and ana-aosa, may collectively be referred to as aasa. Among them, hitoegusa is the principal type used as food.
Hitoegusa is valued for its protein, dietary fiber, vitamin C, calcium and other minerals. It is generally harvested in spring and dried, allowing it to be stored and used throughout the year.
Dried aasa is a versatile ingredient in Okinawan cooking. In addition to aasa-jiru, it can be used in tempura, rolled omelets, rice porridge and juicy, Okinawa’s traditional mixed rice dish.
The dried seaweed is easy to incorporate into different recipes, adding a subtle ocean aroma and a gentle green color. This versatility is one reason aasa has remained a familiar ingredient in Okinawan households.
The main season for aasa is April through September, while spring is particularly associated with its harvest. Because the seaweed is dried after harvesting, however, it can be enjoyed in Okinawan cuisine throughout the year.
Aasa-jiru may be one of the simplest dishes in Okinawan cuisine, but its understated flavor makes it particularly appealing. The soft texture of island tofu, delicate seaweed and clear savory broth come together in a bowl that feels both light and deeply satisfying.
For travelers exploring Okinawan food, aasa-jiru is a wonderful way to experience the flavor of the islands’ surrounding seas without heavy seasoning. Try it for breakfast or as part of a traditional set meal and enjoy the gentle aroma of Okinawa’s coastal waters.