9 cups water, separated
1 handful fresh mint + additional for serving, if desired
1 cup sugar
Place tea bags and mint in a large pitcher than can have hot water poured into it. Pour two cups cold water over the tea bags and mint.
Bring 4 cups water to a roiling boil and pour into the pitcher. Cover with the pitcher's lid or a small plate. Allow to steep for 10 minutes. Remove the tea bags and the mint; add the sugar and stir until dissolved. Add the lemons and the remaining 3 cups of cold water.
To serve pour over ice and garnish with a fresh sprig of mint, if desired.