For the baguettes, dissolve the yeast in 100 g of water and let stand for 10 minutes. Sift the flour into a suitable bowl. Make an indentation in the middle and add the dissolved yeast.
Mix with a little flour to a thin paste and let stand again for 15 minutes. Add salt. Using a wooden spoon, add 250 ml of mineral water in portions and mix to form a dough.
Knead the day by hand at the beginning in the baking bowl until all the flour is incorporated, then on a dry surface until a smooth dough. Knead for 5 minutes. Return to the baking bowl. Cover with a wet tea towel and let rise in a warm place for 1 1/2 hours. Knead again.
If the dough sticks to the surface, dust it lightly with flour. Shape the dough into a ball. Cut this into two large parts. Knead each part one more time and shape into an oblong loaf. Place both loaves on a baking tray brushed with oil or lined with baking paper.
In the meantime preheat the oven to 220 °C.
Cover the baguettes with a wet dishcloth and let them rise repeatedly for 30 minutes. Brush with cold water. Score lengthwise in the center 1 cm deep. Bake for 60 minutes. After 30 minutes of baking and after removing, brush repeatedly with cold water. Baguettes should be just very lightly golden brown. Let cool on the rack.