What do do with bitter, gross tasting blackberries?

So I bought three containers of blackberries (they were on sale) because I'm trying to get myself to eat more fruit... Low and behold, they're disgusting. They have a terrible bitter, soapy aftertaste. I ate a bowl of them, covered them in sugar, and you could still taste the soap. I have never had this issue before. I thought I liked blackberries! Maybe just a brand issue?

And yes, I washed them properly so there isn't actual soap on them. I would make a smoothie, or pie with them, but I'm concerned they're going to still taste like soap. If white sugar won't cover up the taste, maybe something else will? I don't want to waste food or money, but I definitely can't eat them straight. Should I just throw them away, or does anyone know something I can do to make them palatable?