12 fresh strawberries, hulled and quartered
1/4 cup white sugar
7 cups water, divided
3/4 cup white sugar
1 cup lemon juice
2 cups ice cubes
Mix strawberries and 1/4 cup sugar together in a bowl; set aside for juices to release from strawberries, 5 to 10 minutes.
Bring 1 cup water to a boil in a small saucepan; add 3/4 cup sugar. Cook and stir sugar mixture until sugar is dissolved, about 5 minutes. Remove saucepan from heat and cool simple syrup to room temperature.
Stir simple syrup, 6 cups water, lemon juice, and ice together in a pitcher. Add sweetened strawberries and stir.