Cranberry sauce is a thick, gooey liquid with chunks of fruit. Cranberry jelly is a smooth, thick liquid that can be molded to retain the shape of its container when solidified by chilling. They are both made of the same ingredients in the same proportions, but the difference between the sauce and the jelly comes down to pectin. To make cranberry sauce into cranberry jelly all one needs to do is to continue boiling and stirring the sauce until the berries completely break down and release all of their pectin.