Dried beans, cooked in an acidic sauce, haven't softened enough - can I do anything now? I know why my beans haven't softened - I was adapting a recipe (that calls for tinned beans) to use dried - and there's vinegar in the sauce.  I soaked an assortment of beans from different packs overnight, and cooked in the slow cooker on high for 8 hours.  That would normally be plenty even in chilli with a fair bit of tomato.  As the beans came from different packs that were fine a week ago, and  were uniformly too firm, I don't reckon it's that the beans are too old.  They were just about edible last night.  A further 12 hours on low overnight softened them a little more, but they're still firmer than I'd like.  The recipe isn't online but it's beans, onion, garlic, spices, treacle and vinegar, similar to a vegetarian Boston Baked Beans.
The solution for next time is easy - add the vinegar when they're nearly cooked - but I made several portions and would like to make the best of what I've cooked.
Is there anything I can do at this stage to make them soften further? Would neutralising the acid and cooking some more help?
Blender.
That will get them soft.  Then you can fry the bean paste, like refried beans.