Wring out oranges and lemons separately. Measure 600 ml of orange and 300 ml of juice from one lemon.
Mix fruit juices together in a saucepan with Finesse and Extra Gelatinizing Sugar. Bring everything to a boil at high temperature, stirring constantly for at least 3 minutes, then remove from heat. Perhaps skim the boiling mixture, fill on the spot to the brim in prepared jars. Close with twist-off lids, turn to the other side and leave on the lid for 5 min.