Day 1: Place all the ingredients, excluding butter, in a mixer bowl and mix for 5 minutes at slow speed. Increase the speed to medium and continue mixing for 2 minutes. Add butter and mix for 3 minutes at medium speed. Let the dough rest for 30 min at 76-78F. Divide the dough into 250g portions. Round each piece of dough into the ball. Transfer dough balls into a tray, cover with plastic wrap, move to fridge, and let ferment for 12-15 hours at 38-40F.

Day 2: Remove the dough from the fridge and bring to room temperature. Using a rolling pin, roll the dough the long way to spread it out. Fold the top edge of the dough two-thirds of the way down. Rotate the dough 180° and fold the top edge of the dough two-thirds of the way down. Use the heel of your hand to press and seal. With your thumb, fold the dough in half by pushing the dough top down and inwards. Use the side of your other hand to seal the seam around your thumb. Using both hands, start from the middle and roll toward both ends of the dough until it is 50-54cm long with pointed ends. Score the dough by making closely spaced slashes diagonally over the surface of the dough. Place the dough on a baguette pan, scored side up. Begin 2nd fermentation of baguettes at 80-84F for 1 hour and 45 min. Press gently on the dough. The second fermentation is completed if a light fingerprint is visible on the dough. Using a pastry brush, apply egg wash on the surface of the dough. Preheat oven to 410F. Place baguettes into the oven and bake for 14 minutes. Place the finished baguettes on a rack to cool down. Enjoy!