Easy Sourdough Bread for Beginners

Steps

1. Day 1, around 8 a.m.: feed your starter (1 part starter, 1 part flour, 1 part water by weight) and leave it at room temperature. It is ready 4 to 6 hours later when it has doubled, the top is domed and full of bubbles, and a spoonful dropped into a glass of water floats.
2. Around 11 a.m., an hour before the starter peaks, start the autolyse: in a large bowl, mix the bread flour, whole wheat flour and 350 g water at 79°F (26°C) by hand until no dry flour remains. The dough will look shaggy; that's normal. Cover and rest 45 minutes to 1 hour.
3. Around noon, add the 100 g active starter on top of the dough. Wet your hand and work it in by pinching the dough between thumb and forefinger along its whole length, then folding it over itself for 2 to 3 minutes. Cover and wait 30 minutes.
4. Sprinkle the salt over the dough, pour in the remaining 10 g water and pinch again for 2 minutes until you can no longer feel the salt. The dough tightens and turns smoother.
5. Do 4 sets of stretch and folds, one every 30 minutes. With a wet hand, grab the edge of the dough, stretch it up until you feel resistance without tearing, then fold it over the center. Turn the bowl a quarter turn and repeat 4 times. By the fourth set, the dough is smooth, elastic and holds its shape for a few seconds.
6. Then leave the dough covered and untouched at 75 to 79°F (24 to 26°C). The whole bulk ferment (counted from when you added the starter) takes 4 to 6 hours depending on your kitchen. It is done when the dough has grown by about 50 percent, the top is domed with a few bubbles, the edges pull away from the bowl and it jiggles like jelly when you shake the bowl.
7. Around 5 p.m., tip the dough onto an unfloured counter. Using a bench scraper, fold the edges into the center, flip it and drag it toward you in small turns to build a tight ball. Let it rest uncovered 20 to 30 minutes: it spreads a little and relaxes.
8. Lightly flour the top of the round, flip it, gently stretch it into a rectangle, fold the bottom third up and the top third down, then roll it from top to bottom, tightening with each turn. Pinch the seam closed. Dust a banneton (or a bowl lined with a towel) generously with rice flour and set the dough in it seam side up.
9. Cover the basket with a bag or shower cap and refrigerate at 39°F (4°C) for 12 to 16 hours: this is the cold proof, and it happens overnight.
10. Day 2, around 8 a.m.: put the cast-iron Dutch oven with its lid in the oven and preheat to 480°F (250°C) for 45 minutes to 1 hour. Take the dough out of the fridge at the last minute, turn it out onto a sheet of parchment paper and score it with one confident slash about 1/2 inch (1 cm) deep, blade held at a 30-degree angle.
11. Lower the dough on its parchment into the hot pot, cover and bake 20 minutes at 480°F (250°C). Remove the lid, drop the oven to 450°F (230°C) and bake another 20 to 25 minutes, until the crust is deep brown, almost mahogany along the score. The loaf should sound hollow when tapped underneath and read 205 to 208°F (96 to 98°C) inside. Cool on a rack for at least 1 hour, ideally 2, before slicing: the crumb finishes setting as it cools.