Vietnamese Kumquat Soda (Soda Tắc)

Name: Vietnamese Kumquat Soda (Soda Tắc)
Prep time: 10 min
Total time: 10 min
Yield: 2 servings
Cuisine: Vietnamese
Ingredients: 10 whole (about 4 oz) (115 g) fresh kumquats, washed, halved crosswise, seeds flicked out with the tip of a knife; 3 tbsp (38 g) granulated sugar; 16 leaves (8 g) fresh mint leaves, rinsed and patted dry, plus 2 small sprigs for garnish; 1 pinch (½ g) fine sea salt (optional); 2 cups (280 g) ice cubes; 1½ cups (360 ml) soda water or plain sparkling water, very cold

From the MyKitchenBank Kitchen

A bright, fragrant sparkling mocktail in the style of Vietnamese soda chanh. Whole kumquats are muddled with sugar and mint so the sweet peel oils and tart juice flow into fizzy soda water. Refreshing, floral and lightly bitter-sweet.

Prep: 10 min
Cook: —
Wait: 10 min
Total: 20 min
Makes: 2 tall drinks (about 12 oz / 350 ml each)

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Steps

Before you start

Chill the soda water for at least 2 hours so it stays fizzy and the ice melts slowly.
Wash the kumquats well under warm running water, since you will be muddling and drinking from the peel.
Use a sturdy muddler or wooden spoon handle and tall glasses (at least 14 oz / 400 ml).
Total time includes a 10-minute rest that lets the sugar draw out juice and oils.

1
Prep the kumquats
- Rinse the kumquats and pat dry.
- Cut each in half crosswise.
- Using the tip of a small knife, flick out and discard the seeds, which are bitter when crushed.
- Divide the halves evenly between two tall glasses (5 kumquats per glass).
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Ready when: All kumquats halved and seeds removed
Tip: Removing seeds is worth the minute; they make the drink bitter.
2
Add sugar and salt
- Sprinkle 1½ tablespoons (19 g) sugar over the kumquats in each glass.
- Add a tiny pinch of salt to each glass if using; it rounds out the sweetness.
3
Muddle the fruit
- Press and twist the muddler firmly into the kumquats for about 30 seconds per glass, 10 to 12 presses, until the fruit is crushed, the peels are broken up and the sugar looks wet and syrupy.
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Ready when: Fruit is mashed, juice pools at the bottom and the sugar has begun to dissolve
Tip: Press and twist rather than pounding so the glass doesn't crack.
4
Rest to extract
- Let the muddled kumquats sit for 10 minutes, stirring once halfway.
- The sugar will pull more juice and fragrant peel oil from the fruit and dissolve into a loose syrup.
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Ready when: No gritty sugar visible; the mixture looks glossy and orange
5
Gently bruise the mint
- Add 8 mint leaves to each glass.
- Press lightly 3 or 4 times with the muddler, just enough to release the aroma without shredding the leaves.
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Ready when: Leaves are bruised and smell strongly minty but are still mostly whole
Tip: Over-muddled mint turns grassy and bitter.
6
Add ice
- Fill each glass with 1 cup (140 g) ice cubes, packing it over the muddled fruit so the mixture is held in the lower half of the glass.
7
Top with soda
- Slowly pour ¾ cup (180 ml) cold soda water into each glass, tilting the glass slightly to keep the bubbles.
- Stir gently from the bottom up 3 or 4 times with a long spoon to lift the syrup.
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Ready when: Drink is evenly pale orange and still fizzing
Tip: Taste and add 1 tsp more sugar or a splash more soda if you want it sweeter or lighter.
8
Garnish and serve
- Tuck a mint sprig into each glass, add a straw and serve right away while it is cold and bubbly.
- Stir before each sip, as the syrup settles.

Good to know

Tips

Pour the soda slowly down the side of the tilted glass to keep the most bubbles.
Don't skip the 10-minute rest; it is what turns a weak drink into a deeply flavored one.
For a smoother drink, strain the muddled mixture through a fine-mesh strainer into fresh ice-filled glasses before adding soda.
Choose bright orange, firm kumquats; soft or shriveled ones give less juice and a dull flavor.

Make ahead

The muddled kumquat, sugar and mint base (steps 1 to 5) can be made up to 8 hours ahead. Cover and refrigerate, then add ice and soda just before serving.

Storage & reheating

Best served immediately. The assembled drink loses its fizz within 20 minutes at room temperature. The un-sodaed muddled base keeps 1 day in a covered jar in the fridge, though the mint darkens. It is not suitable for freezing as a finished drink, but the muddled base can be frozen in ice cube trays for 1 month; thaw in the glass, then add ice and soda.

Substitutions

fresh kumquats → 4 small calamansi or 1 small lime plus 1 tbsp orange juice. Calamansi is the closest flavor; lime plus orange gives a similar sweet-tart balance, with less peel fragrance.
granulated sugar → 3 tbsp (45 ml) honey or simple syrup. Stir well to dissolve; honey adds a floral note.
fresh mint leaves → Thai basil or lemon balm. Use the same amount; Thai basil gives an anise-like flavor.
soda water or plain sparkling water → Sparkling mineral water or tonic water. Tonic adds sweetness and bitterness, so reduce the sugar to 2 tbsp.