Mix all ingredients, add the salt until late and knead for 10 minutes. The dough should be sticky. Put in the bowl and cover with foil or a tea towel, let rise until the double amount, about 4 hours.

Grease a baking tin with butter and fill them for 2/3 with dough. Sprinkle with some flour and cover with a tea towel. Leave for 1-2 hours until the amount has doubled. Preheat the oven to 275ºC. Place a baking sheet or oven stone in the middle and slide a solid plate on the bottom shelf. Put the loaves in the oven and put a few ice cubes on the bottom plate. Lower the temperature to 200 degrees after 5 minutes. Bake the loaves for another 35 to 40 minutes. Take them out of the oven, the bread should sound hollow if you knock on the bottom and let cool on a rack. Wrap them in a tea towel and let them rest until the next morning.