Blackberry ideas needed

Blackberries are coming into season. These are volunteers so they are a touch on the astringent side, not great for raw eating. Sugar helps cut that so last year I made a lot of blackberry jam. I probably have enough to get through this year so I'm looking for alternative ideas for long term storage. If not I'll make more jam.

This year won't be a big harvest as we cut down so much last year. This means there won't be enough to make wine.