Sour Fish Soup
Canh chua cá
The Mekong Delta's everyday sour soup — catfish simmered with tamarind, pineapple, and tomato, finished with rice-paddy herb and a spoonful of fried garlic.
By Vietnamese Cookbook Kitchen · June 12, 2026
The Mekong DeltaThe Lê Dynasty era, 1428–1789
Kho- Prep
- 25 min
- Cook
- 25 min
- Serves
- 4
- Level
- Beginner
Canh chua means simply "sour soup," and the Mekong Delta is where it grew loudest. Vietnamese settlers reached the delta in the late seventeenth century, in the long southward push the chronicles call Nam tiến, and found a landscape that cooks read as a pantry — catfish and snakehead in every canal, pineapple on the high ground, tamarind trees shading the market towns. The soup they built says all of it in one bowl. It rarely dines alone: across the south it partners cá kho tộ, sour broth against dark salty fish, two dishes that need each other the way a question needs an answer.
The technique is a lesson in layering sourness: tamarind lays the deep base, tomato and pineapple add bright top notes, and the finishing herbs lift the whole thing. Hold one rule close — every vegetable keeps its crunch, and the fish barely cooks. This is not a simmered-down soup but an assembled one, hot and quick, each thing arriving at the bowl at its own best moment. The first spoonful should make you sit up slightly. If it doesn't, add lime, add chili, and try again — the delta would.
The fish goes in late and comes off the heat the moment it flakes. A canh chua that boils its catfish for twenty minutes has already lost the argument.
Lời đầu bếp · A word from the kitchen
Ingredientsnguyên liệu
Serves 4
Broth and fish
- 500 gcatfish steaks — cut through the bone, 2–3 cm thick; basa or swai steaks work, and snakehead is the delta's other favorite
- 40 gtamarind pulp — about 3 tbsp from the seedless block — not the jarred concentrate, unless you must (see the FAQ)
- 1.5 Lwater
- 45 mlfish sauce — 3 tbsp, plus more at the end to taste
- 25 gsugar — 2 tbsp; the delta likes this soup honestly sweet
- 3garlic cloves — minced, for frying in 2 tbsp neutral oil
Vegetables and herbs
- 200 gfresh pineapple — in thin wedges — it seasons the broth as much as it garnishes it
- 2ripe tomatoes — each cut into six wedges
- 150 gelephant ear stem (bạc hà) — peeled and sliced on a hard diagonal; celery is the honest substitute — see the FAQ
- 6okra pods — in thick diagonal slices
- 100 gbean sprouts
- 1 handfulrice-paddy herb (ngò om) — roughly chopped, with a few sawtooth herb (ngò gai) leaves if your market carries them
- 1bird's-eye chili — thinly sliced, for the table as much as the pot
Methodcách làm
Step 1: Wake the tamarind
Soak the pulp in 250 ml of hot water for ten minutes, mash it with a fork, and strain, pressing hard. You want a murky, aggressively sour liquid — this is the spine of the soup, and jarred shortcuts taste like the shortcut they are.
Step 2: Fry the garlic
Fry the minced garlic in oil over medium heat until it is golden — not brown — then pull it off. Half goes into the soup pot with its oil; the other half waits to crown the finished bowls. Golden garlic is nutty; brown garlic is bitter, and there is no way back.
Step 3: Build the broth
Add the water, tamarind liquid, sugar, fish sauce, and pineapple to the pot and simmer five minutes so the pineapple gives up its juice. Add the tomatoes and cook three minutes more, until they slump but still hold their shape.
Step 4: Poach the fish
Slip in the catfish steaks and bring the pot back to a bare simmer. Seven to eight minutes is enough — the flesh should flake at the thick part but still cling to the bone. Skim any foam; a clear canh chua is a point of pride.
Step 5: Stagger the vegetables
Add the okra and cook two minutes, then the elephant ear stem for one, then the bean sprouts for thirty seconds. Each should arrive at the bowl with its crunch intact — the stem in particular is there for texture, squeaky and juice-filled, not for softness.
Step 6: Balance and finish
Taste against a spoonful of plain rice if you can — the soup should run sour first, then sweet, then salty. Adjust with fish sauce or sugar, then kill the heat and shower in the rice-paddy herb, the reserved fried garlic, and the chili. The herb goes in dead last; heat flattens it.
Đồ nghề · The tools
Equipment
Claypot
Thố đấtThe vessel kho was invented in — clay heats slowly, holds a caramel simmer without scorching, and goes straight to the table still bubbling. Season it once with rice water and it outlives you.
Shop on Amazon →Fine-mesh skimmer
Vợt vớt bọtClear phở broth is not a trick, it is patience with a skimmer — take the scum off early and often and the pot rewards you with glass.
Shop on Amazon →Mandoline
Bàn bàoĐồ chua lives or dies on evenness — carrot and daikon cut to the same whisper-thin matchstick pickle at the same speed. Use the guard; every Vietnamese grandmother has the scar that says otherwise.
Shop on Amazon →Fine sieve / muslin
Rây lọcFor straining broth crystal-clear, squeezing coconut milk, and working tamarind pulp through into pure sour. Line it with muslin when the recipe says “clear” and means it.
Shop on Amazon →
Equipment links are Amazon affiliate links. As an Amazon Associate we earn from qualifying purchases, at no cost to you. Disclosure.
Questions from the kitchen
What can I use instead of elephant ear stem?
Celery, sliced thin on a hard diagonal and added at the same moment, gives you the same juicy crunch with a different accent. Vietnamese markets sell the real thing as bạc hà or dọc mùng — peel it well, as the raw skin can prickle sensitive hands. If you find neither, skip it; the soup survives.
Can I use jarred tamarind concentrate?
Yes, with restraint — start with a tablespoon and add by the teaspoon. The concentrate is darker, sourer, and sometimes sweetened, so taste before you commit. The block pulp gives a fresher, fruitier sourness that is worth the ten minutes of soaking.
What do I serve this with?
Plain rice, and classically a claypot of cá kho tộ — the loud, sour soup and the dark, salty braise are the Mekong table's oldest double act. A small dish of fish sauce with sliced chili for dipping the fish is standard practice.
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