Combine all ingredients in a bowl until no dry flour remains. Cover and let the dough rest for about 15 minutes.
Over the next 1½ hours, perform 3 sets of stretch and folds, gently lifting and folding the dough over itself. After each set, flip the dough over, cover, and let it rest.
Cover the bowl and place it in the fridge for an overnight fermentation of 12–14 hours.
Turn the dough onto a lightly floured surface. Divide into 3 equal pieces and shape each into a rough rectangle. Cover and let rest for 45–60 minutes so the gluten relaxes.
Take each piece and gently stretch it into a rectangle. Fold it into a tight cylinder, sealing the seam as you go. Roll lightly with your hands to lengthen each baguette to about 14–15 inches.
Place the shaped baguettes on a floured couche, seam side up. Cover and proof at room temperature for 30 minutes, until light and slightly puffy.
Preheat the oven to 500°F (260°C) with a baking stone in the upper half and a pan of hot water on the lower rack for steam.
Transfer baguettes onto parchment paper, seam side down, and gently dust off excess flour. Score each baguette 3 times with a sharp blade using quick, confident cuts.
Carefully transfer the baguettes onto the hot baking stone or baking tray, being mindful of steam. Close the oven and reduce the temperature to 475°F (245°C). Bake for 15 minutes.
Remove the water pan, rotate the baguettes, lower the temperature to 450°F (230°C), and bake for another 15 minutes until deep golden brown and crisp.