We have a lot of blackberries around here and I usually make a couple of batches of this every summer. I don't use much sugar or pectin -- I like to keep the preserves a little bit runny to mix the fruit with yogourt, pour it over ice cream or cake, or spread it on bread. The preserves thicken once they're open and in the fridge.
4-5 cups picked-over and washed blackberries
1-2 cups pitted whole cherries
1-1 1/2 cups sugar or to taste
2 tbsp. brandy or to tas
Put fruit and sugar into high-sided non-aluminum pot and bring to a boil while stirring. Add brandy, turn heat down but continue to stir until mixture begins to thicken slightly (about 10 minutes). Pour into sterilized jars and seal. Do not turn lids tightly. Process for 8-10 minutes in boiling water. Remove and let cool on counter.
If you don't want to process the preserves, they keep about three weeks in the fridge.
These preserves have a wonderful deep flavour -- not too tart because of the cherries and brandy, and a gorgeous colour. They make great gifts, too.