Mix water, salt, sugar, and yeast in a bowl and stir until everything is dissolved.
350 g water, 11 g fine salt, 3 g sugar, 3 g fresh yeast
Add the flour and mix until all the flour is wet. It's important not to knead the dough; just gently fold the flour into the mixture until it's fully incorporated.
400 g wheat flour
Cover the bowl with a lid or plastic wrap and let it rise until doubled in size. This should take around 7-9 hours.
Preheat the oven to 275 degrees Celsius (525 degrees Fahrenheit), preferably an hour before baking, and place a baking sheet in the oven to heat up.
When the dough has risen, generously sprinkle flour onto a work surface and transfer the dough onto it. The dough is very wet, so make sure to wet your hands. Fold the dough twice: first, fold it completely over in one direction, and then fold it in the opposite direction.
Now, transfer the dough onto the preheated baking sheet. Place parchment paper on the sheet and quickly lift the dough onto it. It can be a bit challenging as the dough is quite liquid, so you may need to practice a few times to get the technique right. Speed is key.
Place the baking sheet on the second-bottom rack in the oven and bake the bread at 275 degrees Celsius (525 degrees Fahrenheit) for 18-20 minutes. The bread should have the classic dark blisters on the surface.
Remove the bread from the oven and let it cool on a wire rack before slicing and serving.