Vietnamese Sweet and Sour Soup (Canh Chua)
Canh Chua is a Southern Vietnamese broth built on tamarind, fish, pineapple, and fresh herbs - tangy, savoury, and light all at once. The balance between souring agent, fish sauce, and sweetness is the whole game here.
Equipment
- 1 medium pot
- 1 fine mesh strainer optional, for clear broth
Ingredients
Broth
- 300 g fish steaks or fillets catfish, barramundi, or snapper
- 750 ml water
- ½ small onion sliced
Souring Base
- 2 tbsp tamarind paste soak in the hot water and strain before using
- 60 ml hot water
Vegetables and Fruit
- 1 tomato cut into wedges
- ½ cup pineapple chunks
- ½ cup bean sprouts
- 3 okra pods cut into 2–3 cm pieces
Seasoning
- 1½ tbsp fish sauce adjust to taste
- 1 tsp sugar adjust to balance
To Finish
- 1 long red chilli sliced, optional
- 1 handful fresh rice paddy herb substitute regular coriander if unavailable
- 1 handful sawtooth coriander substitute regular coriander if unavailable
Instructions
Build Broth
- Add water, fish pieces, and onion to a pot and bring to a gentle simmer.
- Simmer for 10–12 minutes, skimming any foam that rises - this keeps the broth clean.
- Strain through a fine mesh strainer for a clear broth, or leave as is for a more rustic result.
- Return broth to the pot and stir in the strained tamarind water, fish sauce, and sugar.
- Taste: the balance should read tangy first, lightly sweet, then savoury.
Cook Vegetables
- Add tomato, pineapple, okra, and chilli to the broth and simmer for 3–4 minutes until just tender.
Cook Fish
- Add fish fillets or steaks back into the broth if you removed them earlier.
- Simmer for 3–4 minutes until the fish is just cooked through - it should flake cleanly but hold together.
Finish
- Toss in bean sprouts and remove from heat immediately.
- Scatter herbs over the top just before serving.
Notes
Storage
Canh Chua is best eaten immediately. The fish will continue to cook in the residual heat and the herbs will lose their fragrance quickly. If storing, keep broth and fish separate and reheat gently.Key pitfalls:
- Don't boil the fish hard - aggressive heat makes it chalky and clouds the broth; keep it at a gentle simmer the whole way through.
- Skim foam in the first few minutes of simmering, before it gets stirred back in, or the broth will be murky.
- Herbs go in at the very end, off the heat - they're there for fragrance, and that disappears fast.
- Taste the broth after adding tamarind before adjusting anything - different tamarind pastes vary significantly in sourness and concentration.
- Maintain the fish-to-water ratio: 300g fish to 750ml water is the baseline. More water without more fish means a bland broth.
- Fish sauce is doing the work of salt here - too little and the soup tastes flat, too much and it tips harsh with no way back.