Thai Sweet Chili Sauce
A glossy, sweet-tangy-spicy dipping sauce made from fresh red chilies, garlic, rice vinegar and a splash of fish sauce. It simmers in 15 minutes and is far brighter than the bottled kind.
- Prep
- 10 min
- Cook
- 15 min
- Wait
- 30 min
- Total
- 55 min
- Makes
- About 1¼ cups (300 ml), ten 2-tablespoon servings
Steps
Before you start
- Wear gloves or wash your hands well with soap after handling the chilies, and don't touch your eyes.
- Choose red Fresno chilies for medium heat, or use red jalapeños for milder sauce. Use 1–2 red Thai chilies in place of some of the Fresnos for more heat.
- Leave the seeds in for a spicier sauce. Remove them from half the chilies for a milder one.
- Plan on 30 minutes of cooling time. The sauce looks thin while hot and thickens as it cools.
Prep the chilies
- Put on gloves.
- Cut the stems off the chilies and roughly chop them into ½-inch (1 cm) pieces, keeping the seeds for a medium-hot sauce.
- Peel the garlic cloves.
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Ready when: Chilies are stemmed and chopped; garlic is peeled.
Tip: Chilies vary in heat. Taste a tiny piece of one first so you know how hot the sauce will be.
Blend the base
- Add the chilies, garlic, water and rice vinegar to a blender or mini food processor.
- Pulse 8–10 times, then blend for about 15 seconds on low.
- Stop while the mixture is still slightly chunky, with flecks of chili about the size of a grain of rice.
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Ready when: Mixture is bright red and pink with small, rice-sized flecks, not a smooth purée.
Tip: Over-blending makes the sauce cloudy and pale. Short pulses keep the color vivid.
Start the simmer
- Scrape the blended mixture into the saucepan.
- Add the sugar, fish sauce and salt, and stir well.
- Set over medium-high heat and bring to a boil, stirring occasionally, about 3 minutes.
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Ready when: The sugar has dissolved (no grittiness on the spatula) and the surface bubbles steadily.
Tip: Open a window or run the vent fan. Hot chili and vinegar fumes can be sharp.
Simmer to reduce
- Lower the heat to medium-low so the sauce bubbles gently.
- Simmer uncovered for 8–10 minutes, stirring every couple of minutes and scraping the sides, until it reduces by about a quarter and the bubbles look larger and slower.
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Ready when: The sauce is lightly syrupy and leaves a trail on the pan bottom for a second when you drag a spatula through it.
Tip: Don't over-reduce. It thickens a lot as it cools, and boiling too hard or too long can turn it into candy.
Mix the slurry
- While the sauce simmers, stir the cornstarch into the cold water in a small bowl or cup until completely smooth with no lumps.
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Ready when: The slurry is milky and smooth.
Tip: Stir it again right before adding, as cornstarch settles quickly.
Thicken the sauce
- Raise the heat to medium.
- Stir the slurry again and pour it into the simmering sauce while stirring constantly.
- Cook 1–2 minutes, until the sauce turns glossy and slightly translucent and coats the back of a spoon.
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Ready when: Sauce is glossy and coats a spoon; a finger drawn across the spoon leaves a clean line.
Tip: Don't skip stirring. The sauce can clump if the slurry sits in one spot.
Finish and cool
- Remove the pan from the heat.
- Stir in the lime juice, if using.
- Taste and adjust: add a pinch of salt for savoriness.
- Let the sauce cool in the pan for 30 minutes, stirring once or twice, until it is just warm and has thickened to a drizzly, honey-like consistency.
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Ready when: Sauce slowly drips off a spoon like warm honey.
Tip: If it's too thick when cold, whisk in 1–2 teaspoons of warm water.
Jar the sauce
- Spoon the cooled sauce into a clean jar, seal and refrigerate.
- Serve at room temperature as a dip for spring rolls, fried chicken, fish cakes or grilled meat.
Good to know
Tips
- Keep the sauce chunky rather than smooth for the best look and texture, with visible flecks of red chili.
- Use a light-colored pan so you can see the syrup thicken. Dark pans make it harder to judge.
- Thicken just until glossy. The sauce keeps thickening in the fridge, so stir in a little warm water if it sets too firm.
- For a clear, jewel-like sauce, remove the seeds from the chilies and strain out some of the pulp; the flavor will be slightly milder.
Make ahead
Make the sauce up to 2 weeks ahead. The flavor mellows and improves after a day in the fridge. Bring to room temperature for 15 minutes before serving.
Storage & reheating
Room temperature: up to 4 hours while serving. Refrigerator: up to 2 weeks in a sealed jar. Freezer: up to 3 months in a freezer-safe container, leaving ½ inch (1 cm) of headspace; thaw overnight in the fridge and stir. To loosen cold sauce, let it stand at room temperature or warm it gently for 20–30 seconds in the microwave.
Substitutions
- unseasoned rice vinegar → distilled white vinegar. Use 6 tablespoons (90 ml) white vinegar plus 2 tablespoons (30 ml) extra water, since white vinegar is sharper.
- fish sauce → light soy sauce. Use 2 teaspoons (10 ml) for a vegetarian version, which is less funky but still savory. Check the label for a vegetarian-friendly brand.
- red Fresno chilies → red jalapeños or red bell pepper with 1–2 Thai chilies. Jalapeños give milder heat. Add Thai chilies for a hotter sauce.
- cornstarch → tapioca starch. Use the same amount for a slightly glossier, clearer sauce.