Use a knife or a citrus peeler to score the peels of four oranges into quarters. Peel the oranges carefully, trying to keep the peels intact as much as possible. Set the peeled oranges aside and reserve for another use.
Using a sharp knife, cut away the bitter white pith from the underside of the peels.Do not worry if small amounts of white pith remain.
Slice the peels into long, thin strips.Mix water and sugar and boil for 5 minutes after dissolving.Add the strips of peel and turn the heat down to low, until the mixture is just at a simmer. Cook, uncovered and simmering, until the syrup reduces to a quarter of its original volume (the syrup will barely cover the tops of the peels). Do not stir during this process, as that might cause the formation of large sugar crystals. The simmering will take approximately 2 hours.Remove the saucepan from the heat and allow it to cool. Once cool, drain the peels in a colander. At this point, turn your oven to 200 degrees.Place about one cup of sugar in a small bowl. Dredge the peels in the sugar until they are coated, and place them on a baking sheet lined with parchment paper. Add more sugar if necessary.Place the sugar-coated peels in the warm oven and allow them to dry out. This should take approximately one hour, but check them every 20 minutes to ensure that they are not burning or cooking in any way. Alternately, they can be left to sit overnight on a drying rack instead of placed in the oven.
Once peels are completely dry, scrape off any excess sugar clumps. Store them in a dry location and they should keep for weeks. Candied peels can be dipped in melted chocolate and enjoyed plain, or used in cake, cookie, candy, or bread recipes.