Maybe you could thin with grape juice.
I had blueberry pie filling that was so thick I could not use, I used grape juice to thin and it worked great.

I know jam and pie filling are two different things, you have nothing to lose, don't throw out till you try.

shirl

I find overdone jams or jellies make a great sauce when heated and thinned (I usually use fruit juice for sweet and wine for savory). Blueberry glaze/sauce is lovely on chicken and pork.

A thinned blueberry sauce over cheesecake. Awesome and yummy!

Well, blueberry sauce is certainly an option but if I can re-make it and still have jam I'd much rather.

I'm afraid it would take me years to eat 4 jars of blueberry sauce. We are not big dessert eaters here and I can count on my fingers the number of times I've made pancakes over the decades. (I've never made waffles!)

Linda

Linda, I'm sorry to say that I've been very unsuccessful at "unmaking" overcooked jam. (sigh) I have taken a spoonful out of the jar and warmed it as I use it, and that kind of works, but nothing else has given me acceptable results.

I've made more than one batch of "taffy", so at least I can sympathize.....

Annie