Duyen Hai – a rural district of Tra Vinh province in the Mekong Delta region of Vietnam is famous for the unique Clam worm sauce (Nuoc mam ruoi) – one of the specialty foods of Tra Vinh.
Clam worm may occasionally swim upstream to rivers and even climb to land. It is commonly found in all water depths, foraging in seaweeds, hiding under rocks or burrowing in sand or mud. This worm only breeds once before dying. Clam worm only appears for a few days in a year. So that a Vietnamese folk song says: “tháng chín ăn rươi, tháng mười ăn nhộng; bao giờ cho đến tháng mười, bát cơm thì trắng bát rươi thì đầy” (“In September eating clam worm, in October eating lavra; When October comes, The bowl of steamed rice is white and the bowl of clam worms is full”). In fact, the harvesting season of clam worm is in October and September in the lunar calendar. In Viet Nam, they call clam worm a very nice name – “ground dragon”. This kind of worm lives in Hai Duong province, Hai Phong province and many provinces in Mekong Delta region such as Ben Tre, Bac Lieu, Tra Vinh.
Vietnamese people have created many clam worm recipes: Clam worm cake (Cha ruoi), Fermented clam worm, Stir-fried clam worm with galangal, Braised clam worm, Steamed clam worm. All of dishes from clam worm are very delicious and rich-nutrient. In Duyen Hai district of Tra Vinh province, they make an amazing sauce from clam worm and call it Clam worm sauce.
Clam worm is mixed with salt and put into a terracotta jar. Cover the jar with a cloth, dry the jar under the sun for 10-15 days. The longer the jar is dried, the more delicious the Nuoc mam ruoi. Cook the liquid from the jar, cool it down, filter the liquid to receive a clear liquid.
It impresses dinner at the first time for great taste and special smell. Clam worm sauce has a distinctive taste, natural color like honey. It can be used as a dipping sauce or a spice to cook Braised fishes. According to local people, there is no better than eating steamed rice with boiled veggies dipped in Nuoc mam ruoi and Braised fish with Nuoc mam ruoi. It has become a favorite gift to buy in Tra Vinh.