Palm sugar — made from the reduced sap of the palmyra palm (Borassus flabellifer), coconut palm (Cocos nucifera), or sugar palm (Arenga pinnata) — is the primary sweetener of the Thai kitchen. Its flavour is categorically different from refined white sugar: it has a caramel depth, a slight fermented complexity, and a muted molasses note that white sugar entirely lacks. These flavour properties contribute to every dish in which palm sugar is used — they are not incidental but structural.
**Forms:** - Solid block palm sugar (the most common): pale to dark brown, sold in round disks or cylinders. Must be dissolved in liquid (warm water, coconut milk) before adding to a dish — solid palm sugar added directly to a sauce does not distribute evenly. - Soft palm sugar (the highest quality, in the Thai tradition): fresh, slightly moist, and more flavourfully complex than the dried block form. - Coconut sugar: palm sugar made from coconut palm sap — lighter in flavour, slightly more caramel-forward, less molasses-adjacent. **Dissolving block palm sugar:** Shave or grate off the required amount. Combine with a small amount of warm water (2–3 tablespoons per 60g palm sugar) in a small saucepan. Heat gently until dissolved. Cool before using in a preparation that requires balance assessment — the heat makes the sugar taste less sweet than it will at serving temperature. **Substitution:** Light brown sugar is the closest substitution — its molasses content provides some of the depth. White sugar is the least appropriate substitution — it provides sweetness without depth, and the dish loses the complex background note that palm sugar contributes. **Quality:** Darker palm sugar has more complex flavour. Lighter palm sugar is milder. Thompson generally uses dark palm sugar; substitute medium-dark in preparations where the palm sugar's flavour is intended to be clearly perceptible.
David Thompson, *Thai Food* (2002); *Thai Street Food* (2010)