In a small saucepan, combine the water and sugar and heat gently, stirring just until the sugar fully dissolves, without boiling; remove from heat, add the orange and lemon zest, cover, and let steep for 10–15 minutes until aromatic, then strain and let the syrup cool completely.
In a large pitcher, add the orange pulp and lemon pulp and mash gently with a muddler just until juice is released and light structure forms, keeping texture intact and avoiding a purée.
Add the orange juice, lemon juice, 120 ml of the peel-infused syrup, the pinch of fine sea salt, and the ice-cold water, then stir well and taste, adjusting carefully by adding more syrup for sweetness, more lemon juice if it feels too orange-forward, or more water if the flavor is too intense.
Refrigerate for 1–2 hours until fully cold and the flavors are integrated.
Fill glasses with ice, pour over the orange lemonade, and garnish with orange slices and lemon peel twists.
