Bring 500 ml of water to a boil in a kettle.
Pour the boiling water into a heatproof jug or teapot.
Add 2 tablespoons of dried hibiscus flowers to the hot water and stir gently.
Allow the hibiscus to steep for 5–10 minutes, depending on your preferred strength.
Place a fine-mesh sieve over a clean jug or heatproof bowl and strain the tea, discarding the spent flowers.
If desired, stir in 1–2 tablespoons of caster sugar until fully dissolved.
Serve warm immediately, or let the tea cool to room temperature before chilling in the fridge.
To serve cold, pour over ice and garnish with a slice of fresh lemon.
Optional additions: add fresh mint leaves while steeping, or serve with berries or orange slices for extra flavour.
Store any leftover tea in a sealed jug in the fridge for up to 3 days.