I'm making split pea soup (vegetarian, using the Moosewood Cookbook recipe). I've made this several times before, and I remember that at some point the peas dissolve, making a thick broth. I made sure to soak the peas overnight before cooking them. But the soup has been simmering for over an hour now (very low flame, partially covered, other veggies in the soup for the later 40 minutes) and they don't seem close to dissolving.
Did I do something wrong? How can I fix the soup? And how can I avoid this in the future?