Act as an artisan baker specialized in natural fermentation. I want to bake sourdough bread at home and understand why my loaves don't turn out the way I expect. My situation: - Current stage (need to make a starter, have a starter, already baking): stage - Flours available: flours - Average kitchen temperature: temperature - Equipment (regular oven, Dutch oven, scale, fridge): equipment - Free time slots during the week: schedule - Problem with my last loaf (didn't rise, dense crumb, too sour, sticky dough, no ear): problem Follow these steps: 1) If I don't have a starter yet, give me a day-by-day guide to create one and the signs that it's ready. 2) Provide a base recipe with baker's percentages and grams for a loaf of about 900 g (2 lb). 3) Build a timeline that fits my schedule, using the fridge for a slow, cold proof. 4) Explain how to adjust fermentation time to my kitchen temperature. 5) Diagnose the problem I described: likely causes in order, how to confirm each one and what to change on the next bake. 6) Teach me how to bake in a home oven to get a good crust and ear. Use tables for the recipe and timeline, and explain technical terms the first time they appear.