Crisp water chestnuts get cloaked in tapioca starch and tinted ruby-red, then briefly simmered until they turn translucent and chewy. They are spooned into a lightly salted, pandan-scented coconut milk for a cool, refreshing Thai dessert known as ‘crunchy rubies.’ Each bite contrasts the snappy shell with the juicy chestnut and creamy sweet broth.
Prep Time20 mins
Cook Time15 mins
Total Time35 mins
Servings4
Yield4 servings (about 4 cups)
Nutrition Facts
Per serving (estimated)
- 380 kcalCalories
- 22 gFat
- 19 gSaturated Fat
- 46 gCarbs
- 3 gFiber
- 22 gSugar
- 3 gProtein
- 190 mgSodium
- 420 mgPotassium
- 35 mgCalcium
- 3 mgIron
- 7 mgVitamin C
- 0 mcgVitamin A
Ingredients
For the red water chestnuts
- 400 g fresh water chestnuts, peeled and cut into 1 cm cubes
- 1.5 tsp angkwak red syrup or 3 drops red food coloring
- 2/3 cup tapioca starch, plus extra for dusting
- 1 tsp water
- 3 cups water for simmering
For the pandan coconut milk
- 1.5 cups unsweetened full-fat coconut milk, well-shaken
- 1/4 cup granulated sugar
- 1/4 tsp fine sea salt
- 2 pandan leaves, washed and knotted
- 1 tsp toasted white sesame seeds for garnish
Directions
- Toss the water chestnut cubes with the red syrup and 1 tsp water in a bowl until evenly tinted a deep pink; let stand 5 minutes so the color adheres.
- Add the tapioca starch to the bowl and toss gently with a spoon until every cube is coated in a thick, dry-looking layer. Dust a tray with extra starch, spread the cubes in a single layer, and let them rest 5 minutes to set the coat.
- Bring 3 cups of water to a gentle boil in a saucepan. Lower the chestnuts in and simmer 3-4 minutes, stirring once, until the coating turns translucent and the cubes float. Drain and immediately plunge into cold water to stop the cooking; drain again.
- While the chestnuts cook, combine the coconut milk, sugar, salt, and knotted pandan leaves in a separate saucepan. Warm over medium-low heat, stirring, just until the sugar dissolves and the milk is hot but not bubbling, about 4 minutes. Remove the pandan.
- Pour the warm coconut milk into a serving bowl or four individual bowls. Add the drained red chestnuts and let them cool to room temperature, then chill in the refrigerator at least 30 minutes for the classic icy texture.
- Stir gently before serving, scatter the toasted sesame seeds on top, and serve in chilled bowls. Add a few ice cubes if you like it extra cold.
Cook’s Notes
- Canned whole water chestnuts (about 1 large 425 g can, drained) work in a pinch; pat them very dry before coating so the starch sticks.
- For authentic rosy color, use angkwak or pomegranate syrup rather than artificial dye; the natural version gives a softer, fruitier hue.
- Do not boil the coconut milk vigorously or it may break and turn greasy; warm it gently and serve the same day for the creamiest texture.
- For extra crunch, let the coated chestnuts dry on the tray for 10 minutes before simmering so the coating forms a firmer shell.
- Crushed ice can be added directly to the bowl for a restaurant-style ‘nam khaeng’ presentation that keeps the dessert frosty in warm weather.










