Starbucks Iced Black Tea is a cold, caffeinated drink that combines unsweetened English Breakfast tea and ice.
Tea is brewed hot, then quickly cooled down with ice.
English Breakfast tea is a blend of black teas and every brand makes a different mix. Starbucks uses Teavana’s English Breakfast tea to make their black teas, but it's not sold anywhere.
Starbucks makes Iced Black Tea with a black tea concentrate, which isn't sold anywhere so the next closest is Tazo's Awake English Breakfast tea.
Don't get the Tazo Iced Black Tea concentrate since it tastes gross.