Squeeze 4 oranges, measure 250 ml juice. Cut off the peel of 8-10 oranges thickly and remove the fillets. Wash lemon balm, dab dry, pluck leaves. Put fillets, juice and aperol in a pot.
Stir in the jam sugar well. Bring to the boil while stirring over high heat. Cook for about 3 minutes until bubbly (gelling test). Stir in melissa. Fill jam into clean, dry glasses, close them immediately.