I was making baked beans for a friend's party - soaked them overnight in water, followed the direction precisely and they won't won't won't soften - have been cooking them for four hours! Is it the beans? They're from Whole Food's bulk section as opposed to Rancho Gordo, which is what I usually buy and have never had problems with when making simple refriend beans...was just trying to save some money this time. Is it the fact that I added them raw into an acid-y mix of ketchup and worcestershire and vinegar? That seems to be the norm in all the recipes for baked beans I see on here but I've heard that acid can really toughen the beans. Any advice?