Weigh the starter, water, germ, and both flours into the bowl of a stand mixer fitted with the dough hook. (Add the smaller amount of bread flour.) Knead on medium-low speed (2) for 5 minutes. Cover and let autolyse 20 minutes.
Sprinkle on the salt, and knead the dough on medium speed (4) for another 5 minutes. It should be sticky, but not wet, and should pull away from the sides of the bowl as it is kneaded. Add more flour by the tablespoon if necessary. Add the thyme and olives, and knead on medium low (1-2) for another 5 minutes until thoroughly combined. Turn the dough out onto a lightly floured surface and knead a few minutes by hand until the texture feels right, adding as little flour as possible to keep the dough from sticking to your hands and the surface. The dough should feel smooth, springy and elastic; wet enough to be pliable, but not overly sticky.
Place the dough in a large, lightly oiled ceramic bowl or a large plastic container at least twice the size of the dough. Cover the vessel tightly with plastic wrap or the lid, and allow it to rise until doubled, three to four hours. (You can also let the dough rise in the fridge or a cool place overnight. Let the dough come to room temperature before shaping it, and be sure that it has doubled in bulk to properly develop the glutens.)
Gently turn the dough out onto a lightly floured surface, pressing out the air bubbles. Shape into a boule by tucking the edges under itself, then gently rotating the dough on the surface to form a taught outer layer of dough. Here's a quick video of how to shape a boule. To shape into an oval, rock the boule on the counter with your palms until is elongates slightly. If you have a rising basket, sift a light layer of flour onto the inside, and place the boule in it upside-down, pinching the seam shut. (If you don't have a rising basket, place the boule directly on a peel or board dusted with cornmeal or flour.) Place the whole deal in a large plastic bag, such as a trash can liner. Inflate the bag and close it with a twist tie or clip. Let the bread rise a second time until doubled, about 1 1/2 - 2 hours. When the bread is ready to bake, it will hold an indentation of your finger when you press it lightly, rather than springing back.
While the bread is rising, about an hour before you're ready to bake, remove all but the bottom rack of your oven. Place a baking stone on the rack (or a heavy duty baking sheet), and place a metal pan that you don't care about sacrificing (it will get rusty) on the floor of the oven. Crank the oven up to 500º.
When the bread has doubled, gently turn it out onto a wooden peel dusted with flour or cornmeal. Holding a lame or sharp knife at a 45º angle to the loaf, draw the blade, about 1" deep, across the top of the loaf, beginning and ending 2" from the bottoms of the boule. Fill a 1 cup measure with ice cubes. Quickly slip the boule off the peel and onto the stone, and toss the cubes into the hot pan on the floor of the oven. Bake 20 minutes, then turn the oven down to 450º and bake another 20 minutes or so, until the bread is a deep, burnished golden-brown. An instant read thermometer inserted into the middle should read 210º.
Let cool completely on a wire rack, one to two hours, before enjoying. The best way to store this type of bread is in a paper bag at room temperature for a couple days. After that, I put the whole thing, paper bag and all, into a plastic bag and continue to store at room temp.
I like to use a stand mixer for this bread as kneading in the olives by hand can be quite messy. See my recipe for a basic boule for more info on starters and instructions for mixing the bread by hand.Total time: about 9 hours, not including refreshing starterTimeline:Refresh starter four hours before beginning recipe mixknead and autolyse dough, 1 hourfirst rise, 3 - 4 hours (or overnight in fridge)shape dough, 10 minutessecond rise, 1 1/2 - 2 hoursbake, 45 minutescool loaf, 1 - 2 hoursNutritional values are based on one of twelve servings.