"European Peasant Bread" (or bread with a mix of your favorite whole grains)

This was round 2 of the Artisan Bread in Five Minutes a Day baking, and allowed me to use up some miscellaneous non-all-purpose flours in the pantry.
It, like the basic boule recipe, is delicious and versatile -- I made a basic loaf, a few pain d'epi's, and a couple loaves of cinnamon raisin bread just from this batch.

Ingredients
3 cups lukewarm water
1 1/2 tablespoons granulated yeast (2 packets)
1 1/2 tablespoons Kosher salt
1/2 cup rye flour*
1/2 cup whole wheat flour*
5 1/2 cups unbleached all-purpose flour*

*I actually used 4 cups all-purpose flour+1 cup whole wheat flour + 1 1/2 cups spelt flour -- If you like whole grain foods, then you can get away with adding more and increasing the whole grain-to-AP-ratio. I think it is most important to just make sure it all adds up to ~6 1/2 cups of flour.

Cornmeal for the pizza peel


Directions

Mix the yeast, salt and water in a 5-quart bowl. Add the flours and mix without kneading using a stand mixer fitted with a dough hook attachment, a 14-cup food processor with dough attachment, or a spoon/wet hands combo.

Lightly cover the dough and rest it at room temperature until the dough rises and collapses, about 2 hours. Refrigerate the dough and use over the next 14 days -- you can use the dough immediately (as I did) but evidently it’s easier to work with when cold.

When ready to bake, dust the surface of the dough with flour and cut off a 1-pound piece. Dust with more flour and shape it into a ball by stretching the outer layers to the bottom, rotating the dough until smooth on all sides. If you have taken it from the refrigerator, rest the dough on a cornmeal covered pizza peel for 40 minutes (I don’t have a pizza peel so I used a cutting board). If not, it can rest for the 20min the oven is pre-heating.

Set a baking or pizza stone in the center of the oven and preheat it to 450°F 20 minutes before baking. Also, place an empty broiler tray on a different oven rack.

Sprinkle the dough with flour and use a serrated knife to cut slits or “scallops” across the top. Slide the dough onto the baking stone and pour 1 cup of hot water into the broiler tray. Bake until the crust is browned and firm, about 35 minutes (if your loaves are smaller, start checking around 15min!)