Rinse the citrus and cut into quarters. (Be careful not to squeeze the juice from the fruit as the juice will make the final Vin d’Orange cloudy.)
Place everything in a large glass jar with a lid. Stir to dissolve the sugar, then cover and store in a cool space for 40 days.
Check on the mixture every few days, adjusting the sugar if necessary, and pulling out a few pieces of orange if it’s getting too bitter.
After 40 days, remove the solids and strain through cheesecloth into a large measuring cup and then pour into the bottles, being careful not to add any of the sediment from the bottom of the jar.
If the bottles are corked, the Vin d’Orange can be stored at room temperature. If it is in an unsealed bottle, it will keep in the refrigerator for up to a year. Serve chilled, poured over two or three ice cubes, with a twist of orange or lemon.