Hi Rachel, It's not very hard, if a bit time consuming. (Well, OK it is very time consuming) Here is the recipe I use:
1 kg rose hips (opened and seeds taken out) 1/4 litre orange juice 2 tablespoons of good quality honey jam sugar (1:1/2:1/3:1) depending on how sweet you want your jam 1/2 litre water
Stew the rose hips in water and honey until they get soft and strain the mixture through a sieve to get the skin out. Add the organge juice and bring to boil, add the sugar and boil for about 4 minutes. Put in jars and let it cool.
Why can we no longer buy rosehip syrup? We used to get a jug of it on our table at school to serve with rice pudding, then it was 'nannied' away from us for the sake of our teeth, apparently. Does anyone know where this can be bought?