Add 85 g of coarse-ground coffee to a 32 oz glass jar or pitcher.

Pour 950 ml of cold filtered water over the grounds and stir gently until all the coffee is wet.

Cover the jar with a lid or plastic wrap and place it in the fridge. Steep for 12 to 14 hours - no longer or it will turn bitter.

Set a fine-mesh sieve over a clean pitcher and line it with a paper coffee filter. Pour the cold brew through slowly. Discard the grounds. Set the strained concentrate aside.

Rinse 3 g of dried rose petals briefly under cold water to remove any dust. Drain and set aside.

Combine 240 ml of lychee packing syrup and 36 g of sugar in a small saucepan over medium-low heat.

Stir until the sugar dissolves, about 2 minutes. Add the rinsed rose petals.

Reduce heat to low and simmer for 8 minutes, stirring once or twice, until the syrup smells floral and is slightly thickened. Do not let it boil hard.

Remove from heat and strain the syrup through a fine-mesh sieve into a clean glass bottle. Discard the rose petals. Let the syrup cool to room temperature, then refrigerate until ready to use.

Fill a tall glass with ice cubes.

Pour 150 ml of cold brew concentrate over the ice, followed by 60 ml of cold water or oat milk to dilute.

Add 2 tablespoons of lychee rose syrup and stir gently until combined.

Taste and add an extra teaspoon of syrup if you want it a little sweeter. Garnish with a fresh or canned lychee on the rim and serve immediately.