1. Peel and core the apples, removing any bad parts.
2. Cut the apples into rough slices
3. Float the blackberries in cold water to remove dust and debris, then remove any remaining stalks and unpleasant looking berries.
4. If you are squeamish, check for tiny maggots, but actually this isn't necessary as they will be few and far between, and you'll never know in the final jam!. Its nothing when you think of what goes into a shop bought burger!
5. Place the apple slices and blackberries into a preserving pan.
6. Add the sugar and slowly heat the pan, stirring all the time.
7. When the sugar is dissolved and the pan contains a liquid rather than dry fruit chunks, bring the pan to the boil.
8. Continue boiling the jam, and removing any scum that appears on the surface.
9. When a sample of jam sets, pour the jam into prepared jars.
