Gently roll lime, cut end off then cut in half . Cut one half into quarters for one drink.
Put the four lime wedges and sugar into a glass. Put the mint leaves on one hand and clap to release mint aroma. Add mint to glass and gently muddle mixture 8 times to release the lime juice.
Half fill the glass with crushed ice and pour in the Bacardi Carta Blanca. Gently stir the mixture together until the sugar dissolves.
Top up with crushed ice, a splash of the soda water and garnish it with a sprig of mint.