Old-fashioned sourdough bread

Preparing the sourdough starter:

1. Dissolve the yeast in 40 cl of room-temperature water, then mix with the flour.
2. Knead for 10 minutes.
3. Cover the sourdough with a cloth and let ferment for at least 4 hours at room temperature.

Preparing the bread:

1. Dissolve the yeast in 20 cl of water
2. In a large bowl, mix the flours and the salt
3. Add the dissolved yeast
4. Mix then knead gently for 5 minutes
5. Add the sourdough starter and knead for 10 minutes
6. Cover the dough with a cloth and let rise for 2 hours at room temperature (24°C)
7. Drop the dough onto a floured countertop and fold it up and down until you have a ball.
8. Place the ball in a cast iron Dutch oven and let sit for 2 hours
9. Make slight incisions on the top, then bake in a preheated oven at 230°C for around 45 minutes.