4 quarts water
8 cups packed fresh mint leaves
4 cups white sugar
Bring water to a boil in a large pot. Add mint leaves and steep for 15 minutes. Remove tea leaves from water with a slotted spoon, squeezing leaves to extract any additional liquid; discard leaves.
Stir sugar into steeped tea; return to a boil and cook until sugar is completely dissolved and flavors combined, about 10 minutes. Pour tea concentrate into freezer-safe containers and freeze.