Tom yum is the soup that sums up Thai cooking in one bowl: hot, sour, salty and just faintly sweet, all at once, with prawns and a raft of bruised herbs bobbing in a broth that smells like nothing else. It’s on nearly every menu in the country, from a plastic-stool stall to a white-tablecloth dining room, and in December 2024 UNESCO added tom yum goong to its Representative List of the Intangible Cultural Heritage of Humanity, official recognition of a dish most travellers already rank near the top of their Thailand eating list.
This guide covers what tom yum actually is, the clear-versus-creamy split that trips up a lot of first-timers, which herbs to leave in the bowl, where the depth of flavour comes from, roughly what you’ll pay from street stall to fine dining, how to order the heat level, and the instant-noodle cult that grew up around the flavour. Prices are in Thai baht with US dollars in parentheses at ฿33 = US$1 (July 2026), given as ranges because food prices vary by venue and season. If you’re new to eating your way around a Thai table, our how to eat Thai food guide pairs well with this one.
What is tom yum, exactly?
Tom yum is a Thai hot-and-sour soup built on a broth of lemongrass, galangal and makrut (kaffir) lime leaves, seasoned sharp with lime juice, fresh chilli and fish sauce. The name is literally descriptive: tom means to boil, yum refers to the sour-and-spicy flavour, so “tom yum” is roughly “boiled sour-spicy.” UNESCO’s inscription describes the classic prawn version as one where “the prawns are boiled with herbs, including lemongrass, kaffir lime leaves, galangal root and shallots, then seasoned with local condiments,” a dish that “originated among the Buddhist riverside communities in the Central Plains of Thailand.”
You’ll meet it in several forms. Tom yum goong (prawn) is the icon. There’s also tom yum gai (chicken), tom yum thalay (mixed seafood), tom yum pla (fish) and mushroom versions. It’s a shared dish, set in the middle of the table with rice and other plates, not a private starter bowl the way soup often works elsewhere.
Clear vs creamy tom yum: what’s the difference?
The single most useful thing to know is that tom yum comes two ways, and they look and taste noticeably different even though they start from the same herbs.
| Style | Thai name | Look | Taste | Made with |
|---|---|---|---|---|
| Clear | tom yum nam sai | Thin, bright, translucent | Sharp, clean, sour-hot up front | Herb broth, lime, chilli, fish sauce |
| Creamy | tom yum nam khon | Thicker, orange, opaque | Rounder, richer, mellowed sour | Same base plus evaporated milk and roasted chilli paste, sometimes coconut milk |
Nam sai (clear) is the older, more traditional style: a light broth where the sour and spicy notes hit you cleanly, nothing masking the herbs. Nam khon (creamy) takes that same base and stirs in evaporated milk plus a spoonful of nam phrik phao (roasted chilli paste), sometimes with a little coconut milk, which turns the broth orange, thickens it and softens the sour edge with a richer, faintly sweet body. Neither is “the real one,” they’re two legitimate traditions, but nam khon is the version that exploded in popularity and is what a lot of restaurants pour by default. If you have a preference and the menu just says “tom yum goong,” ask which style it is before ordering.
Which herbs are you not supposed to eat?
Three of them: galangal, lemongrass and makrut (kaffir) lime leaves. They’re simmered into the broth to perfume it, but they’re woody and tough, so you eat around them the way you’d leave a bay leaf. Galangal comes as hard, pale ginger-like slices; lemongrass is the fibrous stalk, bruised and cut into batons; makrut lime leaves are the dark green, figure-eight double leaves. Pushing them to the side of your bowl isn’t rude, it’s exactly what Thai diners do.
Everything soft is fair game: the prawns, mushrooms, tomato, onion and any greens. The small red and green bird’s-eye chillies floating in the broth are technically edible but genuinely fierce, so fish them out if you’re heat-shy. For a wider tour of how Thai dishes are seasoned and balanced, our Thai curries explained guide breaks down the same aromatic building blocks in a different context.
Where does the depth of flavour come from?
The engine of tom yum’s richer, rounder character, especially in the creamy style, is nam phrik phao, a roasted chilli paste. It’s made from dried chillies, shallots and garlic fried slowly in oil until dark, often with dried shrimp and a little tamarind and palm sugar. A spoonful stirred into the broth toward the end (not boiled from the start) gives the soup its orange colour, its glossy sheen and a mellow, smoky-sweet undertone that sits beneath the sharp sour-hot top notes.
That layering, bright sour and hot on top, deep and slightly sweet underneath, is what makes a good bowl taste complex rather than just aggressive. You can buy nam phrik phao in a jar in any Thai supermarket; it doubles as a toast spread and a stir-fry base, so it’s worth grabbing if you want to chase the flavour at home. The fresh chilli, meanwhile, is what brings the actual heat, and that’s the part you can dial up or down.
How much does tom yum cost?
Prices span a wide range depending entirely on where you eat and what’s in the bowl.
| Where | Typical price per bowl | What you get |
|---|---|---|
| Street stall / local shop | ~฿60-150 (US$1.80-4.50) | A solid everyday bowl, a few prawns or mixed seafood |
| Mid-range restaurant | ~฿250-600 (US$8-18) | Larger portions, more or bigger prawns, table service |
| Upscale / seafood specialist | ฿600+ (US$18+), often much higher | Big river prawns, lobster, premium presentation |
Prices compiled from Bangkok stall and restaurant listings as of July 2026; they vary by venue, season and seafood cost, so confirm on the day. ฿33 = US$1 (July 2026).
At a neighbourhood stall you’ll commonly pay ฿60-150 (US$1.80-4.50) for a bowl, with the price tracking how many and what kind of prawns go in. Well-known Bangkok street spots land in this band: a heavily loaded bowl at a famous stall can sit around ฿150 (US$4.50), while a plainer bowl at a local shop can be ฿90 (US$2.70) or less. Sit-down and tourist-area restaurants typically run ฿250-600 (US$8-18) or more, and versions built on lobster or giant freshwater river prawns can climb well into four figures in baht at higher-end seafood places. The reliable money-saver: walk five to ten minutes off a hotel strip or a headline tourist street and the same bowl usually costs noticeably less. Bangkok’s best tom yum is often at exactly these unglamorous local spots, which is a theme our Bangkok street food guide runs with in more depth.
How do you order the heat level?
Tom yum can be properly spicy, but the heat is adjustable and every stall is used to the question. The heat comes from fresh bird’s-eye chillies (phrik kee noo), small but potent, plus chilli paste in the creamy version. A few phrases go a long way:
- Phet noi (เผ็ดน้อย) — a little spicy / mild
- Phet (เผ็ด) — spicy, standard heat
- Mai phet (ไม่เผ็ด) — not spicy
If you can’t judge in advance, order it milder. You can always add heat from the chilli condiments on the table, but you can’t pull it back out of the pot. And because much of the burn lives in the whole chillies floating in the broth, simply not eating those, or fishing them out, tames a bowl a lot without changing the flavour.
The instant-noodle cult
There’s a whole parallel life for tom yum flavour in a packet. In Thailand the instant tom yum noodle is a genuine cultural fixture, not just an export curiosity, and the dominant brand is MAMA, made by Thai President Foods, one of Thailand’s largest instant-noodle producers. MAMA’s tom yum shrimp comes in both a clear hot-and-spicy style and a creamy (nam khon) version thickened with coconut-cream powder, neatly mirroring the two styles of the real soup.
Thais don’t just boil and slurp them, they cook with them: yam mama is a spicy salad built around the cooked noodles, and fried “pad mama” turns the packet into a stir-fry. A packet won’t replace a stall bowl heaped with fresh prawns and bruised herbs, but for a fast, cheap, and very Thai hit of the flavour it earns its place. If you get hooked on the taste while you’re here, a few packets are one of the easiest edible souvenirs to take home.
The honest caveats
A couple of things worth knowing. “Tom yum” on a menu doesn’t tell you clear or creamy, so if you care, ask, plenty of travellers order expecting the bright clear broth and get the rich orange one, or vice versa. The heat is real if you don’t specify, especially at local places cooking for a Thai palate, so don’t be shy about saying phet noi. Prawn quality and price track together, a very cheap bowl in a tourist zone may be light on prawns or heavy on filler, while the best-value bowls are usually at busy local shops a little off the main drag. And the woody herbs aren’t a garnish to power through, leaving them is normal, not fussy.
Where to eat it next
Tom yum is only the gateway. Once you’ve got the hang of the clear-versus-creamy split and how to order the heat, the rest of a Thai table opens up fast: our how to eat Thai food guide covers sharing, rice and the balance of dishes, Thai curries explained demystifies the other big soupy-saucy family, and Bangkok street food points you toward the stalls where a ฿100 bowl beats a ฿500 one. When you’re ready to plan actual meals around what’s happening in town, browse live Thailand events for food markets, festivals and pop-ups on while you’re here.
Sources
- UNESCO Intangible Cultural Heritage: Tomyum Kung inscription (2024) — official description and 2024 listing.
- TAT Newsroom: UNESCO recognition for Tomyum Kung (December 2024) — Tourism Authority of Thailand announcement.
- Bangkok street-stall and restaurant tom yum price listings and reviews, 2026 (Eating Thai Food, Tripadvisor and Bangkok food guides), for the ฿60-600+ range.
- MAMA / Thai President Foods product listings for tom yum shrimp instant noodles, clear and creamy (nam khon) varieties.