Hello Lisa! Introducing ice cubes or drinking water to the oven can definitely help with crust development (particularly when baking sourdoughs!). Whilst It's not at all Completely important, it will help produce a wonderful loaf. Here is a tad more information on the process: Baking bread with steam Delighted Baking! https://brazilian-wax68709.blogminds.com/detailed-notes-on-sourdough-traduction-26003231