Heat apple cider in a small pot over medium heat.
Stir in brown sugar until dissolved. Add sage leaves.
Bring to a boil, then immediately reduce to a simmer. Simmer for 5 minutes.
Remove from heat and add orange peel and lemon peel.
Set mixture aside and allow to cool to room temperature, approx 90 mins.
Remove sage leaves and citrus peels.
Pour into a glass jar and refrigerate until ready to use.