Combine the starter, water, and bread flour in a medium bowl until thoroughly mixed. Cover with a plate and allow it to rest overnight (8-12 hours) until it becomes very bubbly and active, with numerous small bubbles throughout the mixture.

Morning: Transfer the entire levain to a large mixing bowl. Pour in the water and add the bread flour, mixing until all the flour is absorbed and a rough dough forms. Cover with a lid or a damp towel and let it rest for 45 minutes (this is the autolyse).

After resting, add the salt and knead it into the dough by pinching and squeezing until it is evenly distributed. Perform a set of stretch and folds (refer to the video), cover the bowl, and let the dough rest for 30 minutes.

Continue with sets of stretch and folds every 30 minutes over a 3-hour period, covering and resting between each session.

Turn the dough out onto a lightly floured surface and divide it into 3 equal parts. Using your hand, gently roll each piece into a tight ball using a circular motion. Lightly dust with flour and cover with a towel, allowing the dough to rest for 30 minutes.

Shaping: Flour your work surface and pat the first dough ball into a rectangle about 9 inches long. Fold the top third down and press with the heel of your hand to seal. Rotate 180 degrees and repeat with the bottom third. Fold the dough in half lengthwise to form a slim shape, sealing the edges again with the heel of your hand. Roll the dough seam-side down to form a baguette shape, pinching the ends if needed.

Place the shaped dough seam-side down on a greased baguette pan or a parchment-lined sheet pan generously dusted with flour.

Cover with plastic wrap and refrigerate overnight.

Morning: Preheat your oven to 500°F (260°C), positioning racks in the middle and one level below. Prepare a baking sheet for ice cubes.

Scoring: Remove the baguette dough from the fridge once the oven is hot. Use a lame, sharp knife, or razor blade to make 3-5 diagonal cuts (¼-½ inch deep) into each baguette.

Baking: Place a handful of ice cubes on the prepared baking sheet and immediately put the baguette dough in the oven on the middle rack. Position the baking sheet with ice on the lower rack. Close the oven and reduce the temperature to 450°F (230°C). Bake for 30-35 minutes until the baguettes are a deep golden brown. Transfer to a wire rack to cool.

Baguettes are best enjoyed fresh on the day they are baked, but they can be stored in a paper bag for an extra day. For longer storage, freeze sliced or whole baguettes. To freeze slices, place them on a baking sheet before transferring them to a freezer bag. For whole baguettes, wrap tightly in plastic wrap and place in a freezer bag. Baguettes can be kept in the freezer for several months.