Blackberry jelly

I have had my usual Sunday jobs to do today and following my jam making yesterday, today I made blackberry jelly. This is the first time I have made this and I didn’t get much output. It’s quite tasty but the seeds in the blackberry need to be removed as they make the jam less palatable. I think I lost quite a lot of the jelly as it was too thick when I tried to sieve it. This is why I only got half a pot. But what I do have is yummy.