You will need warm sterilised jam jars and jam pot covers - prepare jars by washing in hot soapy water and leaving to dry and warm in a cool oven - 130C/250F/Gas ½ for 10-15 minutes.
Layer the fruit and sugar together in a large china bowl, cover and leave in a cool place for 6-8 hours.
Transfer the fruit and sugar to a large preserving pan. Add the balsamic vinegar and heat gently until the sugar has totally dissolved, then bring to the boil.
Boil rapidly for 10-12 minutes or until setting point is reached. Remove from the heat and leave to cool for 20-25 minutes.
Pour into the clean, warm jars, cover with a wax disc and cellophane top, label and store in a cool dark place for at least 2-3 weeks.