Bring 5 cups of water to a boil. Remove from heat and add tea bags. Steep 10 minutes.
Discard tea bags. Pour the tea into a pitcher. Add the blueberry syrup, stirring until totally incorporated. Add the remaining 3 cups of water.
Chill for a minimum of one hour. Serve with lemon slices and mint leaves.
Blueberry Syrup
Combine all ingredients in a small saucepan, except vanilla extract. Crush blueberries lightly and bring to a boil, then simmer for 15 minutes. Blend and strain the sauce. Stir in vanilla.
Notes
The tea will keep in the refrigerator for 3-4 days, be sure to cover the pitcher.