Combine 1 cup granulated sugar, 1 cup water, and 1 tablespoon lemon zest in a small saucepan. Bring to a gentle simmer over medium heat, stirring until the sugar dissolves completely. Once dissolved, reduce heat and simmer 1–2 minutes to infuse the zest.

Remove the saucepan from heat and let the syrup steep with the lemon zest for 10 minutes to develop flavor. Strain the syrup through a fine mesh sieve into a heatproof container to remove zest. Let cool to room temperature, then chill in the refrigerator if not using immediately.

Lemonade

Juice lemons

Roll the lemons on the counter with your palm to loosen juices. Cut lemons in half and juice until you have 1 cup (about 4–6 lemons) of fresh lemon juice. Strain the juice through a fine mesh sieve into a pitcher to remove seeds and excess pulp if you prefer a smoother drink.

Sweeten and dilute

Add 3 tablespoons of the cooled simple lemon syrup to the 1 cup of fresh lemon juice in the pitcher. Stir to combine. Add 4 cups cold water, stir, and taste. Adjust sweetness by adding more syrup (1 tablespoon at a time) or more water to reach your preferred balance (typical final ratio ~1 cup lemon juice : 3.5–4 cups water : 3–6 tbsp syrup depending on tartness).

Chill and serve

Add 2 cups of ice to the pitcher or fill glasses with ice. Pour lemonade over ice. Garnish each glass with lemon slices and 2–3 mint leaves if using. Serve with additional lemon wedges on the side for guests who want extra tang.

Store any leftover lemonade in a covered container in the refrigerator for up to 3 days. Keep the simple lemon syrup separate if you expect to adjust sweetness later; syrup will keep refrigerated for up to 2 weeks.