Step 1

Add the water, sourdough starter, oil, potato flakes, brown sugar, salt, rye flour, bread flour, wheat gluten and yeast to the bowl of a stand mixer fitted with a dough hook attachment. Mix on low speed until the dough has fully come together and looks slightly tacky, about 8 minutes. Increase the speed to medium high and mix until the dough is elastic and slightly sticky, has pulled away from the sides of the bowl and is stuck to the dough hook, about 10 minutes, adding the caraway seeds, if using, during the last 2 minutes of mixing. Transfer to a large greased bowl, cover and proof in a warm spot until doubled in size, 1 hour 30 minutes to 2 hours.

Step 2

Lightly flour a work surface and turn the dough out onto it. Working gently so as not to deflate the dough, pull each of the 4 "sides" of the dough up and into the center, folding the last side to cover the whole top of the dough. Pinch the seams to seal. Roll the dough over so the seams are on the bottom. The dough should be in a large ball.

Step 3

Place the dough ball on a piece of parchment, cover with a damp towel or plastic wrap sprayed lightly with nonstick cooking spray and proof in a warm spot until doubled in size, 30 to 45 minutes.

Step 4

While the dough proofs, place a 5-quart Dutch oven with the lid in the oven and preheat to 450 degrees F for 30 minutes.

Step 5

Remove the hot pot from the oven, remove the lid and carefully transfer the dough with the parchment into the pot. Use a sharp knife or lame to score the bread, cover and place in the oven. Reduce the oven temperature to 400 degrees F and bake for 20 minutes. Remove the lid and continue baking until the bread is a toasty brown and the interior temperature registers at least 200 degrees F, 20 to 25 minutes. Immediately transfer the bread to a cooling rack. Let cool completely before slicing.