Bring 1 cup of water to a rolling boil in a medium saucepan over high heat. The water should be vigorously bubbling to properly extract the flavors from the dried ingredients.
Remove the saucepan from heat and immediately add the dried hibiscus flowers, passion fruit pieces, lemongrass, and mango pieces if using. Stir the mixture gently to ensure all the dried ingredients are fully submerged in the hot water, releasing their vibrant colors and aromas.
Cover the saucepan with a lid and let the tea steep for 5 minutes, allowing the hibiscus to turn the water a deep magenta color. The longer steeping time ensures a bold, fruity flavor that matches the Starbucks intensity.
Place a fine mesh strainer over a heat-safe container and carefully pour the brewed tea through it to remove all the dried fruit and flower pieces. Press gently on the solids with a spoon to extract any remaining flavorful liquid, then discard the spent tea ingredients.
Stir the liquid cane sugar or simple syrup into the hot tea concentrate, mixing thoroughly until completely dissolved. The sweetness should balance the natural tartness of the hibiscus, creating that signature sweet-tart profile.
Allow the tea concentrate to cool to room temperature for about 10 minutes, or speed up the process by placing the container in an ice bath. The tea should no longer be steaming before proceeding to the next step.
Fill a tall glass with ice cubes until it's about three-quarters full, creating a bed of ice that will keep your drink perfectly chilled. The ice will also help dilute the strong tea concentrate to the ideal drinking strength.
Pour the cooled passion tea concentrate over the ice, then add the cold water to dilute to your preferred strength. Stir well with a long spoon, watching as the vibrant pink color swirls throughout the glass, then garnish with a fresh lemon slice on the rim for a citrusy finishing touch.
