Mozuku Slippery Seaweed of the Sea

Mozuku is a fine thread like seaweed grown in the warm, clear seas of Okinawa. According to the Ministry of Agriculture, Forestry and Fisheries, Okinawa accounts for about 99 percent of national production, and it is known for its distinctive slippery and smooth texture. Beyond the refreshing vinegared dish, it brightens island tables in tempura, soups, and many other forms.

Highlights

The thick mozuku that grows in the seas around Okinawa is marked by a distinctive slippery texture and a smooth passage down the throat. Besides being enjoyed simply with sanbaizu vinegar, it is used in tempura and soups, letting you enjoy the scent of the shore and its slippery bite.

Two kinds of mozuku are farmed in Okinawa: "Okinawa mozuku" (commonly called futo-mozuku, the thick kind) and "mozuku" (commonly called ito-mozuku or hoso-mozuku, the fine kind). Almost all of what actually reaches the market is the former, Okinawa mozuku, which is rich in viscosity and whose brown to blackish-brown branches, 1.5 to 3 millimeters thick, divide irregularly. It is a species peculiar to the Ryukyu Islands and boasts the largest production in the country. Compared with the fine mozuku often seen on the mainland it has a firmer bite, and the flavor of the shore spreads the more you chew. The main reason so many people feel that "the mozuku you eat in Okinawa is something else entirely" comes down to this difference in variety.

According to the Okinawa prefectural introduction, mozuku is a low-calorie food rich in dietary fiber and minerals, and it also contains functional components known as fucoidan and fucoxanthin. These components, inseparable from that characteristic sliminess, are part of why mozuku has long been enjoyed as a healthy gift of the sea. The classic vinegared mozuku slips down easily and suits the hot season. Mozuku tempura, coated and fried, is crisp outside and soft inside, offering a different charm.

Enjoying the Seasons

The peak harvest runs broadly from spring to early summer, around April to June, when fresh thick mozuku appears in markets and you can enjoy a firmer bite. The refreshing vinegared dish also helps stir the appetite in the hot summer.

Access and Basic Information

Okinawa accounts for the greater part of national mozuku production. Farming began with demonstration trials of cultivation methods in 1975 (Showa 50), and through joint research by the Onna Village Fisheries Research Group and the Fisheries Improvement and Extension Office, farmed mozuku was landed for the first time in 1977 (Showa 52). About half a century has passed since then, and prefectural mozuku farming output from fiscal 1999 onward has moved between 13,000 and 21,000 tons a year, with waters all over the prefecture now serving as production areas. Behind the single plate you eat on your trip lie half a century of accumulated farming technique. You can taste it around the First Makishi Public Market in Naha and at pubs and regional restaurants, and the market offers fresh and seasoned mozuku as souvenirs, convenient to take home. Seasoned and frozen mozuku keep well, are affordable, and make an easy souvenir.

Practical Travel Notes

Mozuku is a refreshing plate to order between richer Okinawan dishes. Vinegared mozuku is an izakaya standard, perfect as a palate cleanser after fatty dishes like rafute and tebichi. To taste it in season, aim for fresh thick mozuku that appears from spring into early summer. At markets and roadside stations, packs of seasoned mozuku are sold at modest prices and travel at room temperature or chilled, so they suit a souvenir. Mozuku tempura is best at a diner that serves it fresh from the fryer, and paired with soba it makes a light lunch. Rich in minerals and low in calories, it is a reliable way to balance out meals on a trip.

"Mozuku Don," Loved in Okinawan Homes

The mozuku that visitors encounter is mostly the vinegared dish or tempura, but what is often made in Okinawan homes is "mozuku don," a rice bowl. Mozuku is stir-fried together with meat and vegetables and served over rice; the basic method uses squeezed ginger juice to keep down the seaweed's characteristic smell and finishes the dish with a sweet-savory flavor. The ingredients vary from household to household — minced pork stir-fried with finely chopped vegetables, with scrambled egg, a soft-boiled onsen egg or canned tuna added.

What spread this dish was school lunches. Having become a popular standard on the lunch menu, it took root in homes as well, and today it is enjoyed all over the prefecture as an easy, healthy dinner dish. For Okinawan children, mozuku is not only "a small dish of vinegared seaweed" but a rice bowl too — knowing that, you may feel the distance between yourself and the island's food culture close a little.

A Quick Tip

Vinegared mozuku is delicious on its own or with added ginger and cucumber. For the tempura, be sure to enjoy the melting texture fresh from the fryer. Some store bought seasoned mozuku is quite tart, so if you are sensitive to sourness, choosing a broth based type makes it easier to eat.

Souvenir and Takeaway Hints

Mozuku is a slippery seaweed that grows in the seas of Okinawa, a prefectural specialty accounting for most of the national production. Its smooth passage down the throat and the flavor of the shore are its appeal, and "mozuku su," eaten with sanbaizu vinegar, is the standard. It can also be enjoyed as mozuku tempura, in soups and in rice porridge. Fresh mozuku, seasoned mozuku and dried mozuku are available at souvenir shops and by mail order, and the longer-keeping products suit souvenirs well. Being healthy and low in calories is another reason for its popularity. Tasting smooth, slippery mozuku in Okinawa comes highly recommended.

Sources of Information

This article is based on the Okinawa prefectural official website's "Introduction to Okinawa's Main Marine Products," the Ministry of Agriculture, Forestry and Fisheries' "Our Local Cuisine," and information published by each establishment. Prices, menus and seasons may change, so please check each establishment's official information for details.

Sightseeing Checklist

• Budget guide: Packs are affordable, and assortment sets are available too
• Where to eat it: Eating places, izakaya and souvenir shops throughout Okinawa Prefecture
• Best time of day: As a starter or side dish. The tempura is popular too
• Avoiding the crowds: It is easy to buy as a souvenir item
• Enjoy it together with: Vinegared mozuku and mozuku tempura, the seafood of Okinawa, and healthy island flavors

Practical Information

• Share of national production: Okinawa Prefecture's output is about 99 percent of the national total (per the Ministry of Agriculture, Forestry and Fisheries' "Our Local Cuisine," based on more than 15,000 tons in the 2013 marine fisheries production statistics survey)
• Varieties: The two farmed kinds are "Okinawa mozuku" (commonly futo-mozuku) and "mozuku" (commonly ito-mozuku / hoso-mozuku). Almost all is Okinawa mozuku, a species peculiar to the Ryukyu Islands whose brown to blackish-brown branches, 1.5 to 3 millimeters thick, divide irregularly
• Trend in output: Prefectural mozuku farming output from fiscal 1999 onward has moved between 13,000 and 21,000 tons a year (Okinawa Prefecture)
• Main components: A low-calorie food rich in dietary fiber and minerals. It contains functional components such as fucoidan and fucoxanthin
• The beginnings of farming: Demonstration trials of farming methods were carried out from 1975 (Showa 50), and through joint research by the Onna Village Fisheries Research Group and the Fisheries Improvement and Extension Office, farmed mozuku was landed for the first time in 1977 (Showa 52)
• Main areas where it is served: Diners, izakaya and regional restaurants throughout Okinawa Prefecture. "Mozuku don" is also a standard on school lunch menus
• A public facility where you can taste it: Naha City First Makishi Public Market (2-10-1 Matsuo, Naha City / open 8:00–22:00, varying by shop; last orders for cooking on the 1st floor at 19:45 and at the 2nd-floor eating area at 20:00 / closed the fourth Sunday of every month except December, January 1–3, and the 16th and 17th days of the seventh lunar month / no parking)
• A point to note: Some fresh mozuku sold at markets and direct-sales outlets must be kept refrigerated or frozen. When taking it home, arrange to keep it cool and follow the storage method shown on the product label

*Business hours and prices at individual shops vary by establishment.*

(Sources: the Ministry of Agriculture, Forestry and Fisheries' "Our Local Cuisine: Mozuku Don, Okinawa Prefecture," the Okinawa prefectural official website's "Introduction to Okinawa's Main Marine Products," and the Naha City official website's "First Makishi Public Market Basic Information.")

Practical Information for Your Visit

• Share of national output: Okinawa Prefecture accounts for about 99% of Japan's production (Ministry of Agriculture, Forestry and Fisheries "Our Local Cuisine" / more than 15,000 tonnes according to the Heisei 25 (2013) marine fisheries production statistics survey)
• Varieties: Two types are farmed: "Okinawa mozuku" (commonly called futo-mozuku, or thick mozuku) and "mozuku" (commonly called ito-mozuku or hoso-mozuku, thin mozuku). Almost all of it is Okinawa mozuku, a species endemic to the Ryukyu Islands with brown to blackish-brown fronds 1.5 to 3 millimetres thick that branch irregularly
• Trends in production: Since fiscal Heisei 11 (1999) the prefecture's farmed mozuku output has been between 13,000 and 21,000 tonnes a year (Okinawa Prefecture)
• Main nutrients: A low-calorie food rich in dietary fibre and minerals. It contains functional components such as fucoidan and fucoxanthin
• The beginnings of farming: Demonstration trials of farming methods began in 1975 (Showa 50), and joint research by the Onna Village Fisheries Research Group and the Fisheries Improvement and Extension Office led to the first harvest of farmed mozuku in 1977 (Showa 52)
• Main areas where it is served: Diners, izakaya pubs and local cuisine restaurants throughout Okinawa Prefecture. "Mozuku don" is also a standard item in school lunches
• A public facility where you can taste it: Naha City Daiichi Makishi Public Market (2-10-1 Matsuo, Naha City / open 8:00-22:00 (varies by shop; last orders for cooking on the first floor at 19:45 and at the second-floor restaurants at 20:00) / closed on the fourth Sunday of each month (except December), January 1-3, and the 16th and 17th days of the seventh month of the lunar calendar / no car park)
• Points to note: Some of the fresh mozuku sold at markets and direct sales outlets must be kept refrigerated or frozen. If you take it away with you, keep it cool and follow the storage instructions on the label

* Opening hours and prices vary from shop to shop.

(Sources: Ministry of Agriculture, Forestry and Fisheries "Our Local Cuisine: Mozuku Don, Okinawa Prefecture", Okinawa Prefecture official website "Introduction to Okinawa's Main Marine Products", Naha City official website "Daiichi Makishi Public Market Basic Information")