Bring the water to a boil, then remove from heat and let it cool slightly to about 95°C / 203°F. Add the black tea bags and steep for 3–4 minutes only, then remove the bags without squeezing — squeezing extracts excess tannins and will make the final pitcher harsh and drying.
While the tea is still hot, add the light brown sugar and stir until fully dissolved. Sweetening at this stage ensures smooth sweetness and even distribution throughout the pitcher.
Add the lemon zest and orange zest to the hot, sweetened tea. Cover and let steep for 10 minutes to extract citrus oils that add depth and aroma without introducing acidity or bitterness.
Strain the tea through a fine-mesh sieve into a bowl or large measuring jug, removing all zest. Let the citrus-infused black tea extract cool completely before assembling.
Pour the cooled tea extract into a large pitcher, add the fresh orange juice and ice-cold water, then stir gently until fully combined.
Refrigerate for 1–2 hours until fully cold and flavors are integrated.
Fill glasses with ice, pour over the black tea orange drink, and garnish with fresh orange slices.
