Pick off the grapes and rinse them. Put the grapes in a saucepan with the orange juice as well as the lime juice and bring to a boil, simmering over low heat, stirring several times, until the grapes have all burst. Strain the mixture through a sieve and cool.
Weigh out the juice and make jelly with the same mass of jelling sugar and the citric acid in a large saucepan according to package directions. Fill hot into jam jars and turn upside down for 5 min.
Orange juice, juice of 4 limes, no citric acid gave 1700 ml of juice, cooked in 2 portions with 1, 7 kg of jelling sugar.