Phrik Gaeng Som — Southern Sour Curry Paste / พริกแกงส้ม

Southern Thai — this paste is almost entirely absent from Northern and Central Thai cooking; it defines the sour, turmeric-forward character of Southern Thai cuisine

Southern sour curry paste (phrik gaeng som) is one of the most regional and uncompromising of Thai pastes — it uses dried red chillies and fresh turmeric (not kaffir lime rind or galangal) as its defining aromatics, and contains no coconut in its corresponding curry. Fresh turmeric (kamin) is pounded raw into the paste, producing a vivid yellow-orange colour and the characteristically earthy, slightly bitter turmeric flavour that distinguishes gaeng som from all other Thai curries. Kapi content is very high, and dried shrimp may be added. The resulting paste is designed to work with sharp, sour liquid (tamarind water or green mango) rather than coconut cream.

The sourness of gaeng som is the structural element — turmeric paste + tamarind + fish is the Southern trinity that makes this arguably the most distinctly regional Thai curry style.