The characteristic refreshing sourness of roselle fruit creates a very unique and intriguing flavor for the familiar snakehead fish sour soup (canh chua cá lóc).

The roselle plant, also known as bụp giấm or cẩm thanh, is a wild herbaceous plant growing abundantly throughout the Mekong Delta. Roselle is an annual herb reaching about 1.5–2 meters tall, with yellow, pink, or purple flowers. The fruit is onion-shaped, with a fine fuzzy red calyx consisting of several segments surrounding the seed pod. When mature and dry, the seed pod splits open, allowing the seeds to scatter and germinate everywhere.

For many people, the roselle plant is also a beautiful ornamental “flower” for decoration. But for housewives, roselle fruit is an indispensable premium ingredient in pots of sour soup, especially sour soup with shrimp or snakehead fish.

Few people know that the thin, crisp, red segments of the roselle fruit calyx, with their sour taste, are a valuable ingredient rich in nutritional value, both in cuisine and in traditional medicine. The leaves or fruit calyx have a slightly sweet-sour flavor, cooling properties, helping to clear heat, quench thirst, and treat conditions like sore throat, cough, liver and gallbladder issues, high blood pressure, and arteriosclerosis.

Ingredients for the dish include water spinach, pineapple, okra, and roselle fruit. For the best-tasting sour soup, snakehead fish should be wild-caught from the fields, but nowadays these are very rare—most are farmed, so the meat isn’t as sweet and firm. Choose live snakehead fish about the thickness of a wrist. Clean the fish, cut it in half, rinse thoroughly, and drain. Bring a pot of water to a boil on the stove and add the roselle calyces to simmer until soft.

Season the broth to achieve a rich yet refreshing sour taste. Then add the snakehead fish and cook until done. When the soup returns to a boil, add the vegetables, adjust seasoning again, and turn off the heat. Ladle the soup into bowls, sprinkle chopped green onions, cilantro, and a few slices of ripe chili on top for aroma. Eating snakehead fish sour soup cooked with roselle is incomplete without a small bowl of pure fish sauce with chili.

On hot, sunny days, the refreshing sourness of this dish not only whets the appetite but also provides excellent heat-clearing benefits for the family. It’s truly warm and joyful when the whole family gathers around the meal with that one-of-a-kind bowl of fragrant roselle-cooked snakehead fish sour soup.

According to VnExpress