Cool lime syrup is a crisp, pale-green infusion made by simmering fresh lime zest and cold-pressed lime juice with sugar and water until it clarifies into a zesty, translucent sweetener. Thanks to the high concentration of lime oils and natural citric acid, it delivers bracing, electrifying, and sharp notes—often boosted with a hint of dried mint or cucumber for added crispness—making sparkling waters, mojitos, and iced refreshers taste thirst-quenching, more revitalizing, and more “spa-fresh” than regular simple syrup.