Mix the active starter with the water using a spatula until it's soapy in texture.

Add the flour and knead the dough with a stand mixer's dough hook for a couple of minutes. Let it rest for 20 minutes for autolyse.

Add the salt and knead with the same hook for another 5 minutes.

Shape the dough into a ball and leave it in a warm place for a couple of hours to ferment, giving it a stretch and fold during that time.

It's best to refrigerate the dough ball for about 8 hours. Then shape the bread, let it proof for another hour and score it.

Preheat the oven to 250 °C, place a pan on the bottom rack and pour in half a cup of boiling water; before loading, mist the oven and the bread well with water.

Bake for 30 minutes: the first 15 minutes at 250-240 °C, and the remaining time at 220 °C.

Let the finished bread cool completely before tasting.