Cut the peeled carrots into slices, wash the orange well, pour over with boiling water and cut them together with the peel into large pieces (remove the bones).
Combine carrots with orange, pour 1.5 liters of water and cook over low heat until tender. Then grind with a blender into a homogeneous mass.
Pour 3 liters of water into another saucepan, add the chopped mixture, sugar, citric acid, bring to a boil and leave to brew for 8 hours.
After this time, filter through a fine sieve or gauze. Chill in the refrigerator.