Make the simple syrup: In a small saucepan, combine 1 cup water and 1 cup sugar. Warm over medium heat, stirring, until the sugar dissolves completely. Do not boil vigorously. Remove from heat and let cool to room temperature.

Juice the lemons: Roll each lemon on the counter with your palm to loosen the juices. Cut and squeeze until you have 1 cup of juice. Strain out seeds and most of the pulp if you prefer a smoother drink.

Mix the base: In a large pitcher, combine the cooled simple syrup and the lemon juice. Stir well. Add a small pinch of salt if using—it won’t taste salty; it just enhances the flavors.

Dilute to taste: Add 3 cups of cold water and stir. Taste, then add up to 1 more cup water if you want it lighter. The ideal balance should be bright, refreshing, and not too sweet.

Chill and serve: Refrigerate for at least 30 minutes so the flavors meld. Serve over ice with lemon slices and a sprig of mint if you like.