Hello Lisa! Adding ice cubes or drinking water for your oven can definitely assist with crust growth (particularly when baking sourdoughs!). While it is not absolutely essential, it can help generate an attractive loaf. Here is a little bit more details on the process: Baking bread with steam Delighted Baking! https://bangkok-wax86283.loginblogin.com/34704604/helping-the-others-realize-the-advantages-of-sourdough-bread-for-beginners