Canh chua: Vietnamese sweet and sour soup

Canh chua is a Southern Vietnamese sour soup made with a tamarind broth, pineapple, tomato, okra, bean sprouts and fish or shrimp, finished with fragrant herbs and fried garlic. It's sweet, sour and savory at once, and it's light enough to serve with rice as part of an everyday family meal.

It cooks in about 30 minutes, and it's one of the best introductions to the bright flavors of the Mekong Delta.

What does canh chua mean?

• Canh ("kahn," level tone): a broth-based soup served with rice, as opposed to a noodle soup.
• Chua ("choo-uh," level tone): sour.

So it's simply "sour soup." The most common version is canh chua cá, with fish, but canh chua tôm (shrimp) is popular too.

Ingredients you may need to hunt for

Most of these are at Asian grocery stores:

• Tamarind pulp (me): sold in blocks or as concentrate. It gives the sourness.
• Bạc hà (taro stem or elephant ear stem): a spongy stalk that soaks up broth. In the North the plant is called dọc mùng. In Vietnamese, bạc hà also means mint, so look for it in the vegetable section. Skip it if you can't find it.
• Ngò om (rice paddy herb): a lemony, cumin-like herb strongly linked to this soup. Cilantro or Thai basil can stand in.
• Ngò gai (sawtooth herb): optional, for extra fragrance.

Allergen notes

This soup contains fish and fish sauce, and shellfish if you use shrimp. For a vegetarian version, use tofu and mushrooms with vegetable broth and soy sauce or a vegetarian fish sauce.

Ingredients (serves 4 with rice)

• 1 lb (450 g) catfish steaks or another firm white fish, or peeled shrimp
• 1 1/2 oz (40 g) tamarind pulp, or 2 to 3 tbsp tamarind concentrate
• 6 cups (1.4 liters) water or light chicken stock
• 1 cup (150 g) fresh pineapple chunks and 2 tomatoes, cut into wedges
• 6 okra pods, sliced; 1 stalk bạc hà, peeled and sliced (optional); and 2 cups (200 g) bean sprouts
• 3 tbsp fish sauce, 2 to 3 tbsp sugar, and 4 cloves garlic for frying
• A handful of rice paddy herb and sawtooth herb, chopped, plus 1 or 2 chilies

Steps

• 1. Make tamarind water. Soak the tamarind pulp in 1 cup (240 ml) hot water for 10 minutes. Mash with a spoon, then strain, pressing the pulp. Discard seeds and fibers.
• 2. Fry the garlic. Mince the garlic and fry it in 2 tbsp oil over medium-low heat until golden, 2 to 3 minutes. Scoop out and set aside, keeping the oil.
• 3. Season the fish. Toss the fish with 1 tbsp fish sauce and a pinch of pepper.
• 4. Start the broth. Bring the water or stock to a boil. Add the tamarind water, 2 tbsp fish sauce and 2 tbsp sugar. Taste: it should be clearly sour, a little sweet and savory.
• 5. Cook the fish. Add the fish and simmer gently 8 to 10 minutes until just cooked through. Skim any foam.
• 6. Add vegetables. Add pineapple and tomato and simmer 2 minutes. Add okra and bạc hà and simmer 1 to 2 minutes more. Turn off the heat and stir in the bean sprouts; they should stay crisp.
• 7. Finish. Adjust the balance with more tamarind, sugar or fish sauce. Ladle into bowls and top with fried garlic and its oil, herbs and chilies.

Getting the balance right

Canh chua should taste lively, not puckery or syrupy. Taste after each addition:

• Too sour? Add a pinch of sugar or a splash of water.
• Flat? A little more fish sauce adds depth.
• Too sweet? More tamarind, a spoonful at a time.

Tamarind strength varies a lot by brand, so trust your taste over the measurements.

How is it served?

In a Southern home, canh chua is one part of a rice meal. It's classically paired with a salty braised dish, such as cá kho tộ, so the sour soup balances the rich, salty fish. Spoon the broth over your rice or sip it between bites.

For more soups, see Vietnamese soup recipes beyond phở.

Storage

Canh chua is best fresh, since the bean sprouts and okra soften as they sit. If you plan leftovers, store the broth and fish separately and add fresh sprouts and herbs when reheating.

Add the herbs at the very last moment, right before serving, so their fragrance hits the table with the steam.