Tom Yum (ต้มยำ) is a Thai hot-and-sour soup that translates directly to 'boiled + mixed.' The flavour is built on a foundation of lemongrass, galangal, kaffir lime leaves, fish sauce, lime juice, and fresh chilies — producing a broth that is simultaneously sour, spicy, salty, and fragrant.
Tom Yum ramen — primarily an instant noodle phenomenon rather than a restaurant style — adapts this soup into a noodle-forward format. Thai manufacturers like Mama, Wai Wai, and Yum Yum dominate this category. The seasoning typically comes as a dried spice packet plus a chili-oil sachet.
The shrimp (kung) variant is the most common, but chicken (gai) and pork (moo) versions exist. The instant versions tend to lean heavily on citric acid for sourness and capsaicin oleoresin for heat, though premium brands include whole dried lemongrass and kaffir lime leaf pieces.
Key characteristics: clear to slightly cloudy broth, intensely aromatic, sour-spicy flavour profile, typically paired with thin wheat noodles.