Make the Tea: Heat water in a saucepan or microwave until hot but not boiling. Remove from heat and add the green tea bag. Steep for 3 to 5 minutes.
Prepare the Grapefruit: 1) Zest half of the grapefruit to achieve around 1 teaspoon of zest. 2) Cut the grapefruit in half and juice the zested half. 3) Cut the remaining half into slices.
Prepare Glasses: Arrange grapefruit slices into 2 glasses. Add ice to the glasses until they are half filled.
Finish the Juice: Remove tea bag from the water and discard. Add the grapefruit zest and juice. Stir in sweetener. Pour this juice into each glass, filling them halfway.
Make it Sparkle: Top each glass with sparkling water. Add a mint or basil sprig for a pop of color.
Notes
Optional: Add 1/4 inch of fresh ginger or 1/2 to 1 teaspoon of dried ground ginger to the green tea as it seeps. Be sure to remove the ginger piece before adding the grapefruit juice.Nutritional estimates are for zero-calorie sweeteners.