Sort the raspberries, place the raspberries in a large, tall pot and mix with the jam sugar. Wash the chillies, dab dry and cut into rings, removing the seeds. Add chilli rings to the pot.
Bring to the boil while stirring over high heat and allow to boil fizzily for at least 3 minutes. If necessary, skim and pour hot into prepared, sterilized glasses, close and place on the lid for approx. 5 minutes.
Turn the glasses over, let them cool down. Store in a cool and dark place.