Hi Lisa! Adding ice cubes or h2o on your oven can really assist with crust progress (particularly when baking sourdoughs!). Though It's not at all Totally necessary, it can help produce a wonderful loaf. Here is a little bit additional information on the procedure: Baking bread with steam Content Baking! https://donovanbsfpa.collectblogs.com/73852390/not-known-details-about-sourdough-starter-jar-size