In the morning, when your starter has peaked (see Recipe Notes for help), mix 485 g bread flour, 15 g whole wheat flour, 120 g active sourdough starter, 330 g warm water, and 10 g salt. Mix until the ingredients are fully combined and the dough is shaggy. Cover the bowl with plastic wrap, a shower cap, or a cloth, and let it rest for 30 minutes. (This is the beginning of the bulk fermentation.)