Part 1: Creating Your Sourdough Starter (First Time Only)
Two to three days before you plan to bake, create the starter.
In a medium bowl, mix together 1 ½ cups (180g / 6.3 oz) of the bread flour, ⅛ teaspoon of the instant yeast, and 1 cup (240ml) of warm water.
Stir with a wooden spoon until combined.
Cover the bowl loosely with plastic wrap or a clean kitchen towel and place it in a warm, out-of-the-way spot (like on top of the refrigerator).
Stir the mixture every 8 to 12 hours. Over the next 24-48 hours, it will become bubbly, active, and develop a distinct, mildly sour aroma.
Once it's active, your starter is ready!
Part 2: Baking Your Sourdough Loaf
The night before you want to bake, feed your starter.
In a large bowl or the bowl of a food processor, combine all of your active starter with 2 cups (240g / 8.5 oz) of the remaining bread flour and about 1 ½ cups (360ml / 12.2 fl oz) of warm water.
Mix until smooth.
Cover and let it rest at room temperature overnight, or for at least 6 hours. The mixture will become bubbly and foamy.
The next day, reserve your starter for future bakes.
Transfer half of the bubbly mixture to a covered container and place it in the refrigerator. This is your ongoing starter!
To the remaining mixture in the bowl, add the remaining ½ teaspoon yeast, the salt, the rye flour, and the final 1 cup (120g / 4.2 oz) of bread flour.
Mix until a shaggy dough forms. If using a food processor, process until a moist but well-defined ball forms, adding a tablespoon of water at a time if too dry, or a tablespoon of flour if too sticky.
Cover the dough and let it rise at room temperature for at least one hour.
Lightly flour your work surface. Gently tip the dough out and shape it into your desired form—a round boule, long baguettes, or individual rolls.
Place the shaped dough on a floured cloth or parchment paper, cover with a towel, and let it rest while you preheat your oven to 400°F / 200°C.
Place a baking stone or an empty cast-iron skillet in the oven to heat up.
Once preheated, carefully slash the top of your loaf with a razor blade or sharp knife.
Turn the oven temperature down to 375°F / 190°C.
Carefully transfer the dough to the hot baking stone or a lightly oiled baking sheet.
Bake for 30-45 minutes (less for rolls), or until the crust is a deep golden brown and the internal temperature reads at least 210°F / 99°C on an instant-read thermometer.
For a shinier crust, you can lightly spray the loaf with water as soon as it comes out of the oven.
Let it cool completely on a wire rack before slicing to ensure the perfect texture.
Don't be afraid to swap flours. You can use all white bread flour or substitute whole wheat for some or all of the rye flour to change the flavor and texture.
