# Tom Kha Gai (Thai Coconut Chicken Soup)

Tom kha gai is a creamy Thai soup with chicken, mushrooms and coconut milk, scented with lemongrass, galangal and lime. It is rich, fragrant and mildly spicy.

The coconut milk is the star, so keep the heat gentle to protect it. Finish with lime juice off the heat for a bright, sour contrast to the creamy broth.

- Total time: 35 min (prep 15 min, cook 20 min)
- Serves: 4
- Per serving (estimated): 380 kcal, 26 g protein
- Cuisine: Thai. Category: Soup. Diet: dairy-free, gluten-free, high-protein.

## Ingredients

- 2 cups chicken stock
- 2 cans (400 ml each) full-fat coconut milk
- 2 stalks lemongrass, bruised and cut into 5 cm pieces
- 6 slices galangal (or ginger)
- 5 makrut lime leaves, torn
- 450 g chicken thighs, boneless, thinly sliced
- 250 g mushrooms, sliced
- 2 Thai chilies, bruised
- 2 tbsp fish sauce
- 1 tbsp coconut sugar or brown sugar
- 3 tbsp lime juice
- 1/4 cup cilantro leaves

## Method

1. Pour the stock and 1 can of coconut milk into a pot over medium heat. Add the lemongrass, galangal, lime leaves and chilies.
2. Bring to a gentle simmer, not a boil, and cook 8 minutes, until the broth smells floral and citrusy.
3. Add the chicken and mushrooms. Simmer gently for 8 to 10 minutes, until the chicken reaches 165°F (74°C) and the mushrooms are tender.
4. Stir in the second can of coconut milk, the fish sauce and the sugar. Heat for 2 minutes without boiling.
5. Remove from the heat and stir in the lime juice.
6. Taste and balance: add more lime if it needs brightness, or fish sauce if it needs salt.
7. Ladle into bowls and top with cilantro.
8. Eat around the lemongrass, galangal and lime leaves, which are for flavor and not for eating.

## Why it works

- Simmering the aromatics in stock first gives the broth a layered, citrusy base.
- Splitting the coconut milk into two stages gives both a deep body and a fresh creamy finish.
- Gentle heat keeps the coconut milk smooth and prevents it from separating.
- Lime juice added off the heat cuts through the richness and keeps the sour flavor bright.

## The science

- **Coconut milk can crack.** Coconut milk is an emulsion of oil and water held together by proteins. A hard boil can break that emulsion, so the oil floats on top in greasy streaks. Gently heating it keeps the soup silky and well blended.
- **Sour, salty, sweet balance.** Thai cooking balances sour, salty and sweet in each bite. Lime gives sourness, fish sauce gives salt and umami, and a little sugar rounds off the sharp edges. Taste after adding each and adjust until nothing sticks out.

## Tips

- Slice the chicken thinly so it cooks quickly and stays tender.
- Do not boil the soup once the coconut milk is in.
- Use full-fat coconut milk; light versions make a thin, watery soup.

## Mistakes to avoid

- Boiling the coconut milk: it can split and look greasy, so simmer gently.
- Adding lime juice too early: it loses its bright flavor, so add it at the end.
- Using too little fish sauce: the soup tastes bland, so season to taste.

## Variations and swaps

- Use shrimp or tofu instead of chicken.
- Add a spoonful of Thai chili paste for more heat.
- Serve over steamed jasmine rice for a heartier meal.
- Swap galangal for fresh ginger, adding a little extra lime for brightness.
- Swap fish sauce for soy sauce plus a squeeze of lime to make it fish-free, though the flavor will change.

## Storage

Refrigerate within 2 hours for up to 3 days. Reheat gently on low heat to 165°F (74°C), stirring, and do not boil. Freezing is not recommended.

## FAQ

**What does tom kha gai mean?**

Tom kha gai means chicken galangal soup in Thai. Tom is boiled, kha is galangal and gai is chicken.

**Is tom kha gai spicy?**

It is usually mild to medium. You control the heat by adding more or fewer chilies.

**What is the difference between tom kha and tom yum?**

Tom kha is creamy and mild with coconut milk, while tom yum is a clear, sour and spicy broth.

**Can I use ginger instead of galangal?**

Yes. Ginger is a good substitute, though it tastes spicier and less piney than galangal.

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Source: https://cookingscientist.com/recipes/tom-kha-gai (Cooking Scientist). Learn the science of cooking in the Cooking Scientist app for iPhone and iPad: https://apps.apple.com/app/id6830326846