Green curry is a central Thai preparation — the plains around Bangkok and Ayutthaya, where coconut cultivation was abundant and the cuisine developed its characteristic coconut-cream richness. Thompson traces it through the classical manuscripts of the royal court cuisine, where it appears as a preparation of refinement associated with the central region's culinary tradition.
A curry of central Thai origin, pale green from the fresh green chillies and aromatic herbs of its paste, characteristically rich from coconut cream, and balanced at the sweet end of the Thai curry spectrum — its name (keow wan) means 'sweet green'. Green curry is the Thai preparation most widely known outside Thailand and the one most frequently produced incorrectly outside Thailand: too thick, too sweet, the paste commercial and flat, the characteristic fresh green aromatic of the correct preparation entirely absent. The green curry of the classical Thai table is vivid in colour, fragrant with lemongrass and galangal and fresh chilli, and sweet only as a background note behind the primary aromatics.
Green curry's flavour profile is entirely about fresh aromatic compounds — primarily the citral of lemongrass, the acetoxychavicol of galangal, and the linalool/estragole of Thai basil. As Segnit notes, basil and coconut milk is a pairing found across Southeast Asian cooking because the fat-soluble aromatic compounds of basil (linalool, estragole) are efficiently carried and amplified by the fat phase of the coconut milk — the coconut cream acts as both a cooking medium and an aromatic delivery system. The sweet note (palm sugar + coconut cream's natural sweetness) is not mere flavour addition but a functional chemical component: sweetness suppresses the perception of heat from capsaicin, moderating the chilli's burn to a more integrated warmth — which is why green curry, with its generous coconut and palm sugar, has a 'sweeter' heat profile than a Thai salad (yam) of equivalent chilli content.
**Green curry paste (prik gaeng keow wan):** Thompson's paste formula specifies the following aromatics — all pounded in sequence (Entry T-02): - Long green chillies (phrik chi fa): for the paste's characteristic green colour and moderate heat. These are not bird's eye chillies — the elongated variety provides colour and fruit but less heat. - Fresh bird's eye chillies (phrik khi nu sot): for heat intensity. Quantity adjusts the heat level of the finished curry. - Lemongrass: young, tender stalks for the most citrus-aromatic result. - Galangal: fresh, peeled, sliced thin. - Kaffir lime zest: 2–3 teaspoons, rasped from the fruit. - Coriander root: essential — the earthy-sweet note that underpins the brightness of the green chilli. - Garlic and red shallots. - Fresh turmeric: a small quantity for depth and colour (not enough to taste of turmeric). - White peppercorns, coriander seed, cumin (dry-toasted and ground). - Shrimp paste: toasted. - Fresh coriander leaf and stem: added last in the paste and contributing the vivid green colour. Thompson notes: the coriander in a correctly made green curry paste is what makes it genuinely green — without it, the paste is grey-green from the dried and fresh chillies rather than vivid green. **The curry:** 1. Crack 250ml coconut cream (Entry T-03). 2. Add the green curry paste. Fry in the cracked cream for 3–4 minutes until fragrant and slightly darkened. 3. The smell test: the paste is cooked when no raw shallot or garlic note remains — only the complex, integrated aromatic of the cooked paste. 4. Add fish sauce and palm sugar to season the base. 5. Add chicken (or tofu, or prawns) — the protein goes into the paste before the additional liquid. 6. Add remaining coconut milk or cream. Bring to a simmer. 7. Add Thai eggplant (makheua), pea eggplant (makheua phuang), bamboo shoots. 8. Season with fish sauce and palm sugar. 9. Finish: kaffir lime leaves (torn, added at the last minute), fresh sweet basil (horapa) added off heat — never cooked in the curry. 10. Taste and balance. Decisive moment: Finishing with the basil. Thai sweet basil (horapa — a variety of Ocimum basilicum with an anise note distinct from Italian basil) is added off heat, at the very last moment, to a curry that is fully seasoned and fully cooked. Basil cooked in the curry becomes dark, wilted, and tasting of boiled herb. Added off heat: the residual heat of the curry wilts the basil gently while preserving its volatile linalool and estragole compounds. The basil is the green curry's final aromatic note — the fresh, anise-bright punctuation that lifts the entire preparation. It must be added off heat or it is not the green curry of the classical Thai table. Sensory tests: **Sight — the paste colour:** A correctly made green curry paste, before cooking, is vivid green — the colour of young grass. The coriander leaf is the primary colour source. A paste that is grey-green or olive-coloured has either omitted the fresh coriander or used old, yellowing chillies. Colour is a quality indicator before the first spoonful. **Smell — the cooked paste stage:** At 3–4 minutes of frying in cracked coconut cream: the paste should smell deeply aromatic, complex, and fragrant — all raw sharpness gone, replaced by a rounded, integrated note that includes the citrus-aromatic of lemongrass, the slightly medicinal depth of galangal, and the caramelised shallot-garlic base. If any raw note remains: continue frying for 1 more minute. **Taste — the balance:** The finished green curry should taste: primarily aromatic (the paste's fresh herb character dominating the palate), with coconut cream's richness as the background, a perceptible sweetness from the palm sugar that is present but not dominant, a correct saltiness from the fish sauce, and a heat level from the fresh chilli that is present and builds slightly after swallowing. The green curry is lighter, more fragrant, and less heat-dominant than red or massaman. The palm sugar and coconut cream provide the 'sweet' of its name as a soft underpinning, not a dominant note. **Smell — the basil addition:** The moment the torn basil leaves meet the hot curry off heat: a vivid, immediate aromatic release of linalool and estragole — the anise-fresh character of horapa. This smell is the confirmation that the basil is of the correct variety and freshness.
- Green curry paste loses its vivid colour quickly when made — use within 3 days refrigerated, or freeze in portions. The colour degrades as chlorophyll breaks down; the flavour is less affected. - For a green curry of greater depth: add a tablespoon of good pla ra (fermented fish sauce of greater complexity than nam pla) with the coconut milk. Thompson uses this in many of his more complex preparations for the northern and central Thailand-influenced dishes. - The correct Thai eggplant for green curry is makheua — a round, pale green or white eggplant about the size of a golf ball that is crisp and slightly bitter. In its absence, quartered small Italian eggplant, added late, approaches the texture. The pea eggplant (tiny spheres, intensely bitter) is not a substitute — it is a distinct flavour addition with no equivalent.
— **Dark, khaki-coloured curry without fresh aromatic:** Commercial paste used, or the fresh coriander omitted from the paste, or the basil was added too early and cooked. The three most common failures of green curry outside Thailand. — **Flat, sweet curry without depth:** The paste was insufficient (too little paste per volume of liquid), or the coconut cream was not cracked before adding the paste (the paste was simmered rather than fried). The paste quantity for a correct green curry is generous — Thompson's recipes use 4–5 tablespoons of paste per 400ml coconut milk. — **Excessively hot without aromatic complexity:** The paste is over-represented by bird's eye chillies at the expense of the long green chillies that provide colour and fruit. Correct the ratio: more phrik chi fa (long green), fewer phrik khi nu (bird's eye).
David Thompson, *Thai Food* (2002); *Thai Street Food* (2010)