Thai Tom Yum Prawn Soup

About This Recipe

Tom yum prawn soup combines a sharp lime finish with lemongrass, galangal and makrut lime leaf aroma. Prawn shells provide a quick stock base. The broth should balance sourness, fish-sauce salt and chilli rather than relying on sweetness.

Equipment

• ✓ Soup saucepan
• ✓ Knife and board
• ✓ Ladle
• ✓ Fine sieve
• ✓ Food thermometer

Ingredients

• 500 g shell-on raw prawns
• 1.2 litres water
• 3 lemongrass stalks, bruised
• 25 g galangal, sliced
• 6 makrut lime leaves, torn
• 180 g straw mushrooms, halved
• 120 g tomato wedges
• 3–5 bird’s-eye chillies, bruised
• 45 ml fish sauce
• 55 ml lime juice
• 8 g palm sugar
• 15 g coriander

Easy Step-by-Step Method

Complete one numbered step before moving to the next. Keep the heat and timing exactly as written.

Chef Notes & Tips

Lime juice must go in off heat. Boiling it dulls the aroma and can make the soup bitter.

Ingredient choices: Use sound raw prawns and keep shells chilled before stock preparation. Bruise lemongrass and slice galangal for infusion. These woody aromatics are flavouring pieces, not tender soup vegetables.

Cooking control: Prepare and strain the shell broth as directed, then infuse aromatics and cook mushrooms. Add prawns late and cook until pearly and opaque. Finish lime juice after strong heat has eased and taste before adding more fish sauce.

If something goes wrong: Rubbery prawns cooked too long. If the soup is too sour or salty, increase the unsalted aromatic broth rather than sugar alone. Burnt shells or old seafood cannot be corrected with lime.

Ingredient Substitutions

• ↔ Use oyster mushrooms instead of straw mushrooms; soy sauce plus a little seaweed can replace fish sauce.

Food Safety & Doneness

Keep shellfish cold before cooking. Cook prawns until opaque throughout, checking 63°C in large pieces. For shell-on clams or mussels, use live food-grade shellfish and discard shells that remain closed after cooking.

Serving & Plating

Serve promptly with coriander and explain which aromatic pieces are not intended to be eaten. Divide prawns evenly between bowls.

Storage

Refrigerate promptly in shallow covered containers at 4°C or below and use within 3 days. Reheat only the portion needed to at least 74°C throughout. Discard food left unrefrigerated for more than 2 hours, or 1 hour above 32°C.