Tom Yum Soup at Home: Thai Hot and Sour Soup With Prawns

Tom yum is probably the best-known Thai dish in Malaysia. You will see it at Thai-Malay "tomyam" stalls in every town, often in a big pot with seafood or chicken and a sourness that wakes you right up. The classic version, tom yum goong, uses prawns and is either clear (nam sai) or creamy (nam khon), made richer with evaporated milk or coconut milk.

Making it at home is quick once you have the herbs. Most of them are easy to find in Malaysian markets.

Ingredients (3 to 4 bowls)

• 500 g medium prawns, shell on
• 1.2 litres water or light chicken stock
• 3 stalks lemongrass, cut into 5 cm lengths and bruised
• 5 to 6 slices galangal (lengkuas)
• 6 kaffir lime leaves (daun limau purut), torn
• 4 to 8 bird's eye chillies (cili padi), lightly crushed
• 150 g mushrooms (straw or oyster mushrooms), halved
• 1 tomato, cut into wedges, and half an onion, sliced
• 3 to 4 tablespoons fish sauce
• 3 to 4 tablespoons fresh lime juice
• 1 to 2 tablespoons Thai chilli paste in oil (nam prik pao), optional
• 1 teaspoon sugar
• A handful of coriander leaves
• For the creamy version: 4 to 5 tablespoons evaporated milk or coconut milk

Make a Quick Prawn Stock First

Peel the prawns, keeping the heads and shells. Devein the prawns and set them aside in the fridge. Fry the heads and shells in a teaspoon of oil for 2 minutes until pink and fragrant, pressing the heads to release their juices. Add the water, simmer for 10 to 15 minutes, then strain. This step is optional but gives the soup a much deeper seafood flavour than plain water.

Step-by-Step Method

1. Bring the stock to a boil. Add the lemongrass, galangal and half the lime leaves. Simmer for 5 minutes to release the aroma.
2. Add the onion, tomato, mushrooms and crushed chillies. Simmer 2 to 3 minutes.
3. Stir in the chilli paste (if using), fish sauce and sugar.
4. Add the prawns and cook for 1 to 2 minutes only, just until they turn pink and curl. Overcooked prawns turn rubbery.
5. Turn off the heat. Stir in the lime juice and remaining lime leaves. Adding lime juice off the heat keeps it fresh and bright; boiling it can make it taste bitter.
6. For creamy tom yum, stir in the evaporated milk or coconut milk now.
7. Taste and adjust: more lime for sour, fish sauce for salt, chilli for heat, a pinch of sugar to round it out. Top with coriander and serve hot.

Tom yum is all about balance. Taste at the very end and adjust in small amounts. It should be clearly sour and spicy first, then salty, with only a hint of sweetness.

Clear or Creamy?

Clear tom yum is lighter and lets the herbs shine. It is the older style and pairs well with seafood. Creamy tom yum, popular in Bangkok restaurants and Malaysian tomyam stalls alike, is richer and slightly milder because the milk softens the chilli. Try both and see which your family prefers.

The herbs (lemongrass, galangal and lime leaves) are there to flavour the broth and are usually not eaten. Leave them in for presentation or fish them out before serving if you prefer.

Shortcuts and Variations

• Tom yum paste: ready-made pastes from the supermarket are a fine shortcut. Add fresh lime juice and lime leaves at the end to brighten them up.
• Seafood mix: squid, fish fillet and clams all work. Add them in order of cooking time.
• Chicken tom yum: use sliced chicken thigh and simmer for 6 to 8 minutes until cooked.
• Tom yum noodles: pour the soup over blanched rice noodles or instant noodles for a one-bowl meal.
• Vegetarian: use vegetable stock, tofu, extra mushrooms and soy sauce in place of fish sauce.

Serving Ideas

Serve tom yum with plain jasmine rice and one or two simple dishes, such as an omelette and stir-fried vegetables. Our two-minute kangkung belacan is a fast side that goes well with it. For another Thai-inspired weeknight, try the grilled sambal fish in foil.

FAQ

Can I use ginger instead of galangal?

You can in a pinch, but galangal has a sharper, piney flavour that is central to tom yum. Most wet markets sell it cheaply.

How do I keep the soup from being too spicy?

Use fewer chillies, leave them whole instead of crushed, and choose the creamy version, which is naturally milder.

Can I make tom yum ahead?

Make the broth ahead, but add the prawns and lime juice only when reheating, so the seafood stays tender and the sourness stays fresh.

A good tom yum is bold, aromatic and surprisingly fast. Keep some lemongrass and lime leaves in the freezer and you can have a restaurant-quality bowl at home whenever the craving hits.