Step 1

In a large bowl, combine the flours and 300 grams water. Mix just until the water is absorbed by the flour. Cover with plastic wrap and allow to rest for 1 hour.

Step 2

Add the starter and mix in using a Danish dough whisk or your wet hands until fully combined. Sprinkle the salt over the top and drizzle the remaining 10 grams water over the top. Dimple the salt and water in with your hands, using a clawing motion, until fully combined. Knead the dough in the bowl, folding the dough and using your fist to punch it into the rest of the dough, constantly rotating the bowl, until the dough is not very sticky and uniform. If it is sticky, keep your hands lightly wet while kneading.

Step 3

Bulk ferment for 3-3½ hours, during which time do three sets of four folds after the 60, 90 and 120 minute marks.

Step 4

On a lightly floured surface, pre-shape the dough and allow it to rest, uncovered, for 30 minutes.

Step 5

Spread sesame seeds on a sheet of aluminum foil. Shape the dough desired shape, and roll the part of the dough that will be the top in the seeds. Make sure to create tension on the outside of the dough before coating the top with seeds and placing it into the banneton.

Step 6

Wrap the banneton in plastic wrap and refrigerate it overnight for 12-18 hours.

Step 7

In the morning, place a Dutch oven in the oven and preheat it 500° F.

Step 8

30 minutes before you plan to bake the bread, take the banneton out of the refrigerator and transfer it to the freezer. After 30 minutes, remove it from the freezer and remove the plastic wrap. Place a piece of parchment paper over the banneton, and place a cutting board on top of the parchment paper. Flip it over and lift up the banneton.

Step 9

Score the bread as desired. Remove the Dutch oven from the oven, uncover it, and carefully slide the parchment into the hot Dutch oven. Spray water all over the bread or add 3-4 ice cubes and immediately cover the Dutch oven. Bake 25 minutes. Remove Dutch oven lid and reduce temperature to 450° F. Bake an additional 10-15 minutes. Allow the bread to cool to room temperature before slicing.