In a small saucepan, combine 1 cup water with 1 1/2 cups sugar. Place over medium heat and bring just to a simmer, stirring to dissolve the sugar.
Remove from the heat and let the syrup cool to room temperature. Transfer to a mason jar, cover and refrigerate until ready serving.
Squeeze 1 1/2 cups lemon juice. Transfer to a mason jar and refrigerate up to 2 weeks until ready to make lemonade.
To make the full batch of lemonade, pour 7 cups cold water into a pitcher, add the 1 1/2 cups of lemon juice and 1 1/2 cups chilled sugar syrup and stir to combine.
You can also add the lemon juice and sugar syrup to taste. Add ice to glasses when serving.