Strip the berries, wash and blanch for 1 minute in boiling water. Peel and chop the apples. Put the fruits together in a saucepan and bring to the boil. Let the juice steep over a mild heat. Drain through a cheesecloth.
When the juice has cooled down, stir in the same amount of preserving sugar and cook according to the instructions on the packet.
Pour into jars rinsed with hot water, close and turn upside down for 2-3 minutes.