I was trying to customise blueberry jam for a friend who did not like the jam with the entire fruit in it. So I had to filter out the seeds and skin. But the consistency is always a bit runny.
I use Frozen blueberry and for 650 grams of blueberry I used 150 grams honey. 1/2 a lemon's juice. Thawed berries and heated a bit, filtered the pulp and juice. Then added the honey and lemon juice . Brought it to 96°C (205°F because if I boiled more than 98°C it became too hard) and cooled down before packing.