Add the black tea bags to the cold water in a large pitcher. Cover and refrigerate for 8–12 hours. Remove the tea bags without squeezing. The tea should be smooth, clean, and never bitter.
Add the orange peel strips to the cold brew tea and let infuse for 10–12 minutes only, just until a fresh citrus aroma develops. Remove the peel promptly — longer contact adds bitterness and pithiness.
Stir in ½ cup fresh orange juice and taste. Add up to ¾ cup total only if needed. The juice should lightly sweeten and brighten the tea, not turn it into juice.
Refrigerate for 1–2 hours until fully cold and integrated.
Fill glasses with ice, pour over the chilled orange cold brew iced tea, and garnish with thin round orange slices.