Sift the flour. Chill the water until it is very cold. Prepare one large baking sheet, one small deep baking sheet and a linen towel.
Mix flour and ice water thoroughly and let sit for 50 minutes. Then add salt and yeast to the dough base. Knead the dough thoroughly for 10 minutes by hand or using a special mixer attachment. Leave the dough to rest for 20 minutes.
Bring the dough to readiness. Stretch the dough with your hands into a thick layer and fold the edges overlapping towards the center. Leave the dough for 20 minutes. Repeat this step two times. Cover the dough with cling film and leave in the refrigerator for 24 hours. Then remove, divide into 4 parts and leave at room temperature for 20 minutes.
Preheat the oven to 250 degrees. At this time, form the baguettes: carefully stretch each part of the dough with your hands into a rope of the desired length. Place on a floured towel and lift the towel between the baguettes, creating dividers. Place support along the edges. Leave for 30 minutes.
Bake baguettes. Sprinkle a baking tray with flour, place baguettes on it, make several cuts diagonally with a sharp knife. Pour boiling water into a small baking tray and place it on the bottom of the oven. Bake the baguettes with steam for the first 10 minutes. Then remove the pan with water and bake for another 10 minutes.
Serve the baguette hot, cut into slices and brush with butter.