Combine the lime juice and simple syrup in a pitcher and stir until the syrup is fully blended in, about 30 seconds.

Cover and chill the lime mixture for 20 minutes.

Pack each mug or glass to the top with ice, the drink loses its chill fast without a full load.

Pour about 2 tablespoons of the lime mixture into each ice-filled mug.

Top each mug with ginger beer, pouring slowly down the side of the mug so the fizz does not foam over.

Stir once with a bar spoon, just enough to combine without losing the carbonation.

Garnish each mug with a lime wheel and a mint sprig, pressed gently between two fingers to release the scent before dropping it in.