Hello Lisa! Incorporating ice cubes or water on your oven can really assist with crust development (particularly when baking sourdoughs!). Although It's not at all Completely vital, it may also help develop a beautiful loaf. Here is a tad more information on the method: Baking bread with steam Happy Baking! https://conkey-s-bakery26814.blogolize.com/sourdough-pizza-dough-fundamentals-explained-67683161