Hi Claire, the first (bulk) rise does occur overnight at room temperature. In this recipe the lengthy rise is required to give the dough time to rise and ferment properly because you're starting with a very small amount of sourdough discard. While you could allow the shaped rise to occur at room temperature instead of in the refrigerator, you'll need to be a lot more attentive to the dough and its progress, because the dough is more likely to over-ferment. Also, the dough will be harder to transfer and score when it comes time to bake. We like the ease and flexibility that putting the shaped loaves in the refrigerator provides. 

• Reply