Kumamoto Oysters Flavor Profile

Kumamoto OysterSee image licensing info

Kumamoto Oysters are deep-cupped with petite meats, have a mild brininess, sweet flavor and a honeydew finish. They are a favorite for both new oyster eaters and connoisseurs.

Kumamoto oysters originated in Yatsushiro Bay, Kumamoto Prefecture, Kyushu Japan and were shipped to the US in 1945. But strangly, even though they are extreemly popular in the US, they are unknown in Japan today. Kumos from California are cultivated by Inter-tidal Longlines while Kumos from Washington are culitvated with the Rack & Bag method. Regardless of where they are grown they have very distinctive highly sculptured, fluted shells with deep cups. The Oyster Guide calls the Kumamoto the ‘Chardonnay of oysters’ and are among the most popular oyster due to their luscious fruity flavor and light brininess. “Kumies’, as they are lovingly called, are a small oyster, only slightly larger than the Olympia oyster.

Kumamoto OysterSee image licensing info

Since they are native to the warmer waters of Japan, they do not spawn in the cold waters of the Pacific Northwest. And because of their consistent, mild flavor, Kumamoto oysters are a favorite both among oyster aficionados and the novice oyster lover. In our restaurant we sell about three times as many Kumos compared to other oyster varieties.

Most oysters on the market are named after the area they were cultivated (Penn Cove, Quilcene, etc), but Kumamoto oysters simply are sold as Kumamotos regardless of their area of origin. It take about 3 years for a Kumie to grow to market size. They are cultivated primarily in Puget Sound’s Oakland Bay (WA), Humboldt Bay (CA), and Baja, Mexico.


Kumamoto Oyster
Location South Puget Sound, WA -or- Humbolt Bay, CA
Species Kumamoto Oyster (Crassostrea sikamea)
Oyster Availability Year around
Size 2″ to 3″
Oyster Cultivation Inter-tidal Longline (CA) -or- Rack & Bag (WA)
Oyster Flavor Profile Kumamoto Oysters are deep-cupped with petite meats, have a mild brininess, sweet flavor and a honeydew finish. They are a favorite for beginning oyster eaters and connoisseurs.
Map See Oyster Map


Kumamoto oysters were classified as a new variety of oyster by Amemiya in 1928: “This variety is common in the shallow, muddy water of Ariake Bay in Saga Prefecture (Japan). It is a dwarf or stunted form, and is devoid of commercial value owing to its small size.” Apparently the Japanese enjoy a larger oyster. If he had only known how popular they would become!

I’ve found several variations on the history of how Kumamoto oysters arrived in the US. Pacific oysters have been imported to the US from Japan since around the 1890’s. After WWII ended the demand for oysters increased in the US. In late 1945 Japan was asked to export 80,000 cases of oyster seeds. They did not have enough of the typical Pacific species oyster to fill the order, so they shipped Kumamoto oysters with them which resulted in an “accidental import” of the species in about 1946-1950. The first shipment of Kumamoto oyster seed arrived in Seattle, WA in 1946.

In the same time frame, between 1947- 1953, the Washington Department of Fisheries brought in experimental Kumamoto seed which was planted in Washington, Oregon and Hawaii. The success of these plantings caused several commercial growers to produce Kumos for the market. And in 1951 they were so popular that they were rated in the top three oysters selling in the Chicago Stock Exchange where it was known as the “Western Gem”. By the late 1960’s the US had wheened itself of the need for Japanese seed and the oyster was now commonly marketed as “Kumamoto Oyster”.

By the1980’s, improper handling of seed put purebred Kumamotos near extinction. In Japan, they were already non-existent due to pollution. And in the Pacific Northwest, Kumos and Pacific oysters had cross-breeded and finding pure Kumamoto seed was looking impossible. A frantic search ensued along the West Coast, and a few hundred “true blue” Kumamotos were found on property owned by Taylor Shellfish Farms, and also in Tomales Bay, CA.

Where to Buy Kumamoto Oysters

Penn Cove Shellfish
Taylor Shellfish
Willapa Kumamoto oysters

See proper shellfish storage methods for the best way to maintain the shelf life and flavor of your oysters. Also, check-out our list of where to buy raw oysters.


Comments from before Site Migration

BELLINGHAM JOE []    [ Feb 24, 2014 ]

Taylor Shellfish Farms   is the only place to get excellent Kumamoto Oysters


OYSTERGIRL []    [ Jul 04, 2012 ]

One very large producer of Kumomoto oysters is Oregon Oyster Farms (Newport Oregon) and not only do they sell locally, they are shipped nationwide. O.O.F’s Kumomoto’s are rated number 2 in the nation according to their store manager. the meats are 1-2″ in length, very plump and have a sweet, mild, almost nutty flavor. they are grown on suspension strings.


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Juan Soler

Best Kumamoto Oysters I have ever tried were from Baja California, Mexico. There is an isolated, remote protected bay down there called Bahia Falsa. Zero discharges of any kind into the bay with good, strong currents to keep the oysters, fed, oxygenated, growing and healthy:

Last edited 1 year ago by ChefsResources
process process

The only good Kumamoto oysters are from Oregon Oyster Farms in Newport Oregon. The end.

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