In the bowl of a stand mixer with dough hook attached, dissolve the yeast in the warm water with the sugar and let it proof (5-10 minutes until foamy).
In a small bowl, add the flours and salt. Give it a few whisks to combine together.
Add the flour to the bowl a small portion at a time and mix on low speed. Once you have added all the flour increase the speed and mix until the dough starts to pull away from the sides of the bowl. If you notice the dough is too sticky, add about a tablespoon more of dough at a time until you get a dough that is not too sticky to handle.
(If you’re mixing by hand, mix until ingredients have just come together and form a smooth dough). When dough is ready, turn mixer off and remove the the dough hook.
Grease a large bowl. Place the dough in the bowl. Cover with plastic wrap and place in a warm spot until doubled in size, about 1 1/2 hours (the goal is to not have the dough be too springy).
Sprinkle a little flour on a clean counter. Carefully remove the dough without disturbing it too much onto the counter. Pull the corners together to form a round bowl and place the dough back into the same bowl (sprinkle a little flour into the bowl) seam side down. Cover with a tea towel and let it rise while the oven heats up.
Preheat oven to 460 F with rack in lower third of oven. Heat a covered 3 1/2 quart heavy ovenproof Dutch oven (9 inches in diameter) with the lid on for 30 minutes or until dough is ready.
Place a sheet of parchment paper on your counter (about the length of a baking sheet). Sprinkle on a little flour. Place your loaf seam side up on on the parchment paper.
Carefully remove preheated pot from oven, and uncover.
Remove the towel from top of bowl and quickly but carefully lift the dough using the corners of the parchment paper and place the dough into pot, seam side up (the dough is on the parchment paper). Sprinkle a little more flour on top if it has been absorbed while rising.
Cover with lid. Bake for 30 minutes.
Uncover pot, and bake until bread is dark brown, 15-20 minutes.
Carefully lift bread using the parchment paper from pot and transfer to a wire rack to cool completely. Be sure to let cool completely before slicing.