When added to yeast rolls, fats such as shortening, butter, lard and vegetable oil make for a softer and moister texture than rolls made without fats. Unlike French breads, which are made without added fats and go stale within a few hours after being baked, yeast rolls made with fats will stay fresher for a longer period of time -- up to three days.
Break Out the Butter
When you are switching butter for shortening in any yeast roll recipe, you should use sweet, or unsalted, butter. Salt is added to butter to help preserve it, which gives it a longer shelf life. Unsalted butter has a shorter shelf life and is a fresher product. Using salted butter will also change the flavor of the rolls by making them too salty. You do not need to change the flour or liquid amounts in the original recipe. Since both butter and shortening are solid fats, they can be used interchangeably.