Add 2 liters of water to a medium pot.
Add ½ cup sugar to the water.
Stir the water and sugar together until the sugar starts to dissolve.
Add 1 cup dried hibiscus leaves to the pot.
Stir the hibiscus leaves into the water and sugar mixture.
Place the pot over medium heat.
Bring the mixture to a boil.
Once it starts boiling, let it boil for about 5 minutes. The water should turn a deep red color.
Turn off the heat.
Cover the pot with a lid.
Let the hibiscus steep for 30 minutes. This helps the flavor and color become stronger.
After 30 minutes, strain the hibiscus leaves from the liquid using a fine mesh strainer.
Discard the hibiscus leaves.
Let the hibiscus juice cool slightly.
Transfer the hibiscus juice to a pitcher.
Refrigerate for at least 3 hours, or until fully chilled.
When ready to serve, fill glasses with ice.
Pour the cold hibiscus juice over the ice.
Serve immediately.