The method
The schedule on the home page is what to do. This page is why — written for the point where you have baked a few loaves and want to understand which rules can be bent.
A starter is ready when it triples within six hours and smells of yoghurt rather than acetone. If it smells sharply of nail varnish it is hungry, not dead — feed it twice a day for two days and it will come back. Ours lives in the fridge and gets fed the night before a bake, which is the only maintenance it receives.
Mixing flour and water alone, then resting an hour before adding anything else, does more for dough handling than any amount of kneading. The flour hydrates fully and the gluten begins organising itself without help. Skip it and the dough stays sticky for the whole first hour.
Four sets of stretch-and-folds, spaced 45 minutes apart, build the same structure as kneading with a fraction of the effort and no floured worktop. By the last set the dough should stretch thin without tearing and hold a dome when left alone.
This is the step that decides the loaf. Not double — a rise of about half again, with a domed top and a wobble like set jelly when the bowl is nudged. Under-proofing gives a tight crumb; over-proofing gives a flat loaf that spreads when scored. Given the choice, stop early.
Overnight in the fridge is optional for flavour and close to essential for handling. Cold dough holds its shape, scores cleanly and goes into a hot pot without deflating. It also moves the bake to whenever suits you.
A preheated cast-iron pot traps the loaf's own steam, which is what produces a blistered, glossy crust at home. Twenty minutes with the lid on, then twenty to twenty-five with it off. Take it darker than instinct suggests — pale sourdough tastes of very little.
Strong white bread flour is the easiest place to start. Wholemeal ferments faster and absorbs more water; rye faster still. Swapping in more than about 20% of either without adjusting the water or shortening the bulk rise is the most common cause of a sudden run of bad loaves.