Tom Yum Goong (Thai Hot and Sour Shrimp Soup)

Nam sai (น้ำใส) means 'clear water' — the original, classic version with a transparent, intensely aromatic broth. The flavour is clean, sour, hot, and deeply herbal with no dairy. Nam khon (น้ำข้น) means 'thick/creamy water' — the same soup finished with evaporated milk or coconut milk, producing a pale, opaque, slightly richer broth. The creamy version is more internationally popular and is what most Thai restaurants abroad serve. In Thailand, nam sai is considered the purer and more traditional form. Both are made from the identical base; the milk is added per bowl at the end, not into the pot, so one batch of soup can serve both preferences.

Ginger is the most common substitute but produces a noticeably different result. Galangal has a sharper, more peppery, piney, almost medicinal flavour compared to the warm, floral heat of ginger. The difference in tom yum is significant because galangal is one of the three defining herbs. If using ginger as a substitute, add a grind of black pepper to approximate the peppery note. Frozen galangal is an excellent alternative to fresh and is widely available at Asian supermarkets — it can be sliced from frozen and used directly in the soup.

In Thai serving tradition, these aromatics are left in the soup for visual presentation and to continue releasing flavour as the soup cools slightly at the table. They are not meant to be eaten — they are woody, fibrous, or too leathery to chew pleasantly. Thai diners naturally push them to the side of the bowl when eating. When serving guests unfamiliar with the dish, it is polite to mention: 'the lemongrass, thick slices, and double leaves are for flavour only.' Some cooks prefer to strain and remove the aromatics before serving — this produces a visually cleaner bowl and makes eating easier, with no loss of flavour.

Yes. Tom yum chicken (tom yum gai) uses chicken sliced thinly and simmered 5 to 6 minutes. Tom yum fish uses firm white fish in 3 cm pieces added in the final 2 minutes. Tom yum mushroom (tom yum hed) is vegetarian: use vegetable stock, omit the shrimp, add a larger variety of mushrooms (oyster, enoki, king oyster), and replace fish sauce with soy sauce. The shrimp stock step is skipped for non-seafood versions. The soup base and herb profile remain identical.

Citrus juice contains volatile aromatic compounds that give it freshness and brightness. These compounds evaporate rapidly when heated — lime juice added to a simmering pot loses most of its top-note aroma within seconds, leaving only a flat, one-dimensional sourness and slight bitterness. Adding lime juice off the heat — or directly into the bowl before ladling the soup over it — preserves the floral, sharp citrus character that is one of the defining flavours of tom yum. This is not a minor detail: the difference between heated and fresh lime juice in the bowl is clearly perceptible.