Once the dough is puffy, knock the air out and divide it into three equal portions.
Starting with one of the 3, pat the dough into a flat oval. Working from one long side of the oval, roll it up into a tight log and then use the heels of your hands to roll the log until it is approximately 12" long.
Repeat with the two remaining portions of dough. Place all three next to each other lengthwise and gently press three of the ends together to start braiding. Braid the three logs together until you get to the other end. Once you reach the other end, press the ends together.
If the start of your braid is a little loose or messy, turn the braid 180 degrees, unstick the starting ends and re-braid them to create a cleaner tighter braid.
Line the loaf pan with a rectangle of parchment that measures approximately 8" wide and 15" long. The parchment should go down a long side, across the bottom and back up the other side.
Tuck about 1"-2" of the ends under the braid and then lower it into the loaf pan.
Drape a piece of plastic or a kitchen towel over the top and set aside to proof.
It will take between 30-45 minutes to proof, the dough should reach the top edges of the pan. The dough should also not spring back if poked, if it does, leave it to proof a bit longer.