Hello Lisa! Introducing ice cubes or drinking water for your oven can definitely help with crust development (particularly when baking sourdoughs!). Although It's not absolutely important, it will help generate an attractive loaf. Here is a little bit more information on the method: Baking bread with steam Content Baking! From https://gregoryy23e3.blogscribble.com/28270952/5-easy-facts-about-sourdough-bread-recipe-described