Add <quantity>100<unit>ml</unit></quantity> of room temperature water and <quantity>100<unit>g</unit></quantity> of bread flour to a bowl

Mix vigorously with a spatula

Add <quantity>50<unit>g</unit></quantity> of sourdough starter and mix

Move to a jar and close the lid. Let it rise for approximately 8h at <temperature>24<unit>°C</unit></temperature>. The starter is ready

Add <quantity>240<unit>g</unit></quantity> of water, <quantity>255<unit>g</unit></quantity> of 13.5% bread flour and <quantity>45<unit>g</unit></quantity> of 14% whole grain flour to a bowl

Mix the flour and the water for 45s. Press cling film directly on the dough and let it rest for 2h so it becomes softer

Add <quantity>70<unit>g</unit></quantity> of the starter

Mix again for 45s by hand. Cover again and proof at around <temperature>24<unit>°C</unit></temperature> for 1h so the dough can grow

Add <quantity>6<unit>g</unit></quantity> of salt and mix. Cover again and let it proof at around <temperature>24<unit>°C</unit></temperature> for 1h so the dough can grow

Wet your hands and slide them under the dough. Lift it up slowly while pulling it towards you. Let the dough fold underneath itself on the way down. Repeat on all four sides

Let the dough proof for 1h at around <temperature>24<unit>°C</unit></temperature> for 1h so the dough can grow

Transfer the dough to a damp workbench

Gently pull the dough from all sides to spread it into a square

Fold the dough two times in one direction and three times in the other direction. Return it to the bowl and cover it. Let it rest for 2h so it can grow

Transfer the dough to a lightly floured workbench

Fold the dough halfway and firmly roll the fold. Repeat on the remaining three sides.

Dust flour on a banneton and place the dough in it, seam side up. Cover it and place it in the refrigerator to cold proof overnight for 10h-18h so it can grow

Place a bread pan or a large dutch oven in the oven. Preheat it for 30m at <temperature>260<unit>°C</unit></temperature>

Sprinkle flour on the bread pan

Place the dough on a parchment paper, seam side down. Score it with a blade and place it in the bread pan

Cover the bread pan and bake for 20m so the dough expands

Remove the lid and bake it again at <temperature>220<unit>°C</unit></temperature> for 15m until the crust is firm and deep golden brown. The sourdough bread is ready

Enjoy your sourdough bread!