I made a caramel sauce for a dessert ahead of time, and of course, it has seized up. What should I do to get it to liquefy again. It is a like a rock! I knew it would happen, but I just figured I could re-heat it on the stove, but now I am a little hesitant to do so. Should I add water, cream? Or, should I just heat it up? Thanks for all the help!