Kaeng Som Recipe (Southern Thai Sour Curry)

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Kaeng som recipe with shrimp and a simple homemade curry paste, perfect for any day of the week with a portion of steamed rice. This Southern Thai sour curry makes a fantastic dinner with intense flavors of tangy, spicy, and salty.

Top-down view of kaeng som, Southern Thai curry with shrimp, carrot and beans in a white dish.

Heads-up: Southern Thailand is a place known for its rich, flavorful curries and seafood dishes. If you’re new to Thai cuisine, you might want to try a milder dish like Thai green curry or this authentic panang curry before diving into the intense flavors of this sour soup.

If you can handle strong flavors, also try some of my other Southern Thai cuisine recipes, like khua kling and this Thai jungle curry recipe.

What is kaeng som

Kaeng som is a popular sour curry originating from Southern Thailand, beloved in Southeast Asia. Flavored with tamarind for sourness, fish sauce for saltiness, chilies for heat, and a bit of palm sugar to balance it, this spicy curry omits coconut milk and uses water instead.

Bird's eye view of a spoonful of vegetables and curry sauce over a white dish with Southern Thai sour curry.

Southern Thai curry

A trip to the land of smiles isn’t complete without visiting Southern Thailand, and visiting Southern Thailand isn’t complete without trying the unique and flavorful regional curries!

You’ll find this low-calorie Southern curry listed on menus in Southern Thai restaurants as an orange or yellow curry, all thanks to a generous amount of fresh turmeric.

Kaeng som curry soup with shrimp, carrots, yard long beans, and papaya slices in a white dish.

It’s a real flavor bomb, with a blend of pungent shrimp paste, tangy tamarind, and spicy chilies.

Quick tip: if you’re ever visiting the beaches of Southern Thailand, ask for a mild version of kaeng som, also known as gaeng som (แกงส้ม). It’s as amazing, but you won’t be wiping sweat off your brow while chugging down cold drinks for the next 15 minutes.

The classic version of this dish often uses fish and shrimp, but this is an easy recipe so, we’ll be using shrimp only. If you do decide to use fish, opt for a firm fish since it will be boiled. Quality isn’t crucial here – barramundi or snakehead fish is fine.

Overhead view of Thai shrimp curry with vegetables in a white dish.

Speaking of fish quality, did you know that lots of Thai people living in the rural areas of Thailand don’t have access to ‘premium’ fish? I would be the last person to tell you that you need ‘high-end fish’ to cook an authentic Thai meal.

Kaeng som comes with a lot of variations. Some regions even include flowers like sesbania grandiflora. If the thought of using flowers freaks you out, trust me, some of my grandmother’s best recipes include flowers!

For our version, we’ll use basic vegetables like yard-long beans, carrots, and green papaya fruit. You can find a list of substitutes later, after the instructions section.

Can’t get enough of Thai curries? Try my Thai beef panang curry recipe, my gaeng daeng recipe, or this Thai massaman chicken curry.

5 Reasons to try this recipe

Unique and flavorful: You’ve probably tried Thai classics like authentic Thai red curry, so it’s time for something new. This dish is perfect for those who like intense flavors of Thai cuisine.
Grandma-said-aroy: My Thai grandmother gave her approval for this recipe, declaring it “aroy”, which is Thai for delicious.
Simple ingredients: If you’re a fan of Southeast Asian cuisine, you’ll probably have most of the ingredients needed to make this curry from scratch in your kitchen pantry already.
Healthy option: Most Thai curries rely on full-fat coconut milk, but this one is made with water. Plus, we’ll be using lots of vegetables, herbs, and spices, to achieve an authentic Thai flavor without extra calories.
Customizable: Not a fan of spicy food? Simply adjust the number of chilies in the curry paste. To increase or decrease the sourness, change the amount of tamarind paste. Homemade food is always so much better than takeout, since you get to tune the flavors to your taste!

Ingredients

Ingredients can be sourced at Asian grocery stores and Asian markets.
The exact measurements are in the recipe card at the end of this post.

Curry

Shrimp – Opt for large, peeled shrimp like black tiger shrimps. You can add firm fish like barramundi, snakehead, catfish, or tilapia for variation.
Tamarind paste – This tangy ingredient is the heart of this dish, giving it the sour flavor it’s known for. If you’re not fond of a sour flavor, add to taste.
Palm sugar – In this curry, palm sugar is added to balance out the spicy and salty flavors, not so much to add a sweet flavor.
Fish sauce – This staple of Thai cuisine adds umami and a salty flavor to the curry.
Yard-long beans, carrots – A simple choice of veggies, feel free to switch it up.
Unripe papaya – Often used in som tum Thai aka green papaya salad. In this Thai sour curry shrimp recipe, the unripe fruit maintains a firm texture.
Water – No coconut milk, water is the base for this curry, that’s why it’s so strong in flavor and not as creamy as most coconut curries.
Kaeng som curry paste – For an authentic Thai flavor, we’ll make homemade curry paste, a blend of spices and aromatics.

Kaeng som curry paste

Large dried spur chilies, dried chilies – A combo of large dried chilies and smaller bring a smoky spice and concentrated heat. Dried chilies tend to be spicier than fresh chilies, so if you’re not used to spicy flavors, add to taste.
Shrimp paste – A fermented condiment that adds umami to Thai dishes.
Finger roots – Also known as Chinese ginger or “krachai” in Thai. Adds an earthy, peppery taste.
Shallots
Garlic
Salt

Note: A granite mortar and pestle is the best way to get authentic texture and flavor, but using a food processor is a good shortcut that saves you time.

How to make gaeng som

To make authentic gaeng som, we’ll start by making our homemade gaeng som paste. Once the paste is ready, we’ll make the curry.

Make kaeng som curry paste

Use a mortar and pestle to pound the dry ingredients first: salt, dried red spur chilies, and dried chilies. Then, add the remaining ingredients and grind into a fine paste. Alternatively, you can use a food processor and mix all ingredients at once.
Cook curry paste and vegetables

Fill a pot with water and place it over medium heat. Add the curry paste and bring to a boil. Once boiling, stir in fish sauce, tamarind paste, and palm sugar. Then, add the vegetables.
Add shrimp

Let the curry simmer for 5 minutes, or until the vegetables are soft to your liking. Add shrimp and cook for 2 more minutes, or until the shrimp is cooked through. Serve immediately.

Recipe tips and tricks

Use fresh ingredients: For the best taste, use fresh ingredients instead of frozen.
Save time: The curry paste can be made ahead of time and stored in an airtight container in the fridge.
Taste test: Not all tamarind pastes taste the same. Add to taste, or else the curry flavor might be too sour (although this curry is supposed to have a sour taste).

Kitchen tools

Granite mortar and pestle or food processor: For making the gaeng som curry paste.
Cutting board and chef’s knife
Measuring spoons and cups
Dutch oven or pot
Wooden spoon

Variations and substitutes

Finger root: If you can’t find finger root, try galangal or ginger.
Vegetarian: For a vegetarian curry, use tofu and sub fish sauce with vegetarian fish sauce.
Vegetables: Kaeng some can be made with lots of different vegetables like Chinese cabbage, cabbage, cha om, daikon, cauliflower, phak bung, morning glory, bamboo shoots, coconut shoots, taro stems, and more.
Protein: Not a fan of seafood? Use chicken, pork, beef, or any meat of your choice.

How to serve

Pair this kaeng som recipe with a portion of jasmine rice or brown rice for a healthier alternative.

Pro-tip: Letting the flavors meld for a day will intensify the curry.

How to store

Let the leftovers cool down before transferring them to an airtight container. Store them in the refrigerator for up to 3 days.

Freezing instructions: Use a freezer-safe bag and freeze for up to 3 months. Thaw in the fridge overnight.

Reheating instructions: Reheat using a microwave or on the stovetop over medium-low heat, stirring occasionally.

Fun facts

Gaeng som falls under the curry section, but to me, it’s more of a sour soup. This water-based curry is totally different from the classic coconut curries you might be used to.
Laos and Malaysia have their own version of this Thai dish, with their own local touch.

Frequently asked questions

Is this recipe gluten-free?

Yes, this recipe is gluten-free, but you should double-check the labeling of your fish sauce brand, since some brands add in some gluten-containing ingredients.

Is this recipe spicy?

Yes, this curry recipe is pretty spicy. You can adjust the spice-level by lowering the number of chilies used in this recipe.

Can I make this in advance?

Yes. The flavors improve if you let it set for a few hours or longer. Just reheat it properly when you’re ready.

What does gaeng mean in Thai?

In Thai, “gaeng” generally refers to a category of dishes known as curries. But, “gaeng” can also include a curry/soup-like dish prepared using a base of water or stock.

More Thai recipes with curry paste you’ll love

Thai roasted duck curry – A creamy coconut curry sauce with fresh pineapples, roasted duck, and juicy tomatoes.
Hot and spicy beef – An easy stir-fry with beef and spicy red curry paste.
Tod mun pla – Delicious fish cakes with egg, herbs, and spices.
Pad prik king – Red curry stir-fry with crisp yard-long beans.
Top-tip: Try this chicken khao soi recipe, a comforting egg noodle soup rich in flavors with traditional garnishes.

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