Instructions

1. 1
   Remove the zest from the oranges in strips, leaving behind the bitter white pith.
2. 2
   Combine the sugar and orange zest in a container, and let this sit in the fridge for 24 hours. The sugar will extract the liquid from the citrus peels and produce a syrupy liquid.
3. 3
   Stir the orange juice into the sugar mixture until everything is dissolved. Strain out the solids to yield slightly under ½ cup (120 ml) syrup.
4. 4
   To make the finished soda, combine 1 volume of syrup with 3 volumes of carbonated water.