Hello Lisa! Incorporating ice cubes or drinking water towards your oven can definitely help with crust advancement (especially when baking sourdoughs!). While It isn't Unquestionably necessary, it may also help make a lovely loaf. Here is a tiny bit additional information on the procedure: Baking bread with steam Satisfied Baking! https://judahngvly.dsiblogger.com/61029326/not-known-details-about-sourdough-starter-jar-size