Green Curry Paste (Krung Gaeng Khiew Wan)

Green curry (gaeng khiew wan — literally 'sweet green curry') is central Thai in origin, and its combination of fresh chilli heat with coconut milk sweetness is the balance for which the preparation is named. Thompson notes that the 'sweet' in the name does not refer to an added sweetness but to the quality of the colour — a term of aesthetic appreciation for the vivid green of the fresh chilli paste.

The green of this paste is not from vegetables — it is from fresh chillies, specifically the small, intensely hot green bird's eye chilli (prik kee nuu) and the longer, milder green spur chilli (prik chee fa). Green curry paste is the hottest of the common Thai curry pastes, not the mildest — the fresh chillies provide a heat that is sharper, more immediate, and more penetrating than the mellower warmth of dried chillies in red paste. It is also the most aromatically fresh: the volatile citral of lemongrass and the bright, sharp note of kaffir lime zest are more pronounced in a green paste because the fresh chillies do not provide the smoky, dried depth that moderates the top aromatics in red.

As Segnit notes, lemongrass and coconut milk is among the most extensively documented of all tropical flavour pairings — the lemongrass's citral (specifically geranial and neral, the two forms of citral) dissolves into coconut fat with exceptional efficiency and is released thermally during cooking, producing the signature fresh-citrus top note of green curry. Green chilli's chlorogenic acids (the source of its fresh, slightly green, vegetal heat) complement the lemongrass citral in a way that red chilli's capsaicin-dominant heat profile does not — the green curry's heat is literally different in chemistry from the red, not merely in intensity.