In a medium bowl, mix the levain ingredients until just combined. Cover the bowl and let the levain ferment at room temperature for 10 – 12 hours.

In a small bowl, combine the soaker ingredients. Cover and let rest for 2 – 12 hours.

Place the final dough ingredients, except the soaker, into the bowl of a stand mixer. Mix on low speed until the ingredients are incorporated, about 4 or 5 minutes. The dough will be sticky and have a medium consistency.

Continue mixing on low or medium speed until the dough reaches a medium level of gluten development. This might take about 5 minutes, but will depend on your mixer.

Add the soaker and mix in low speed until it is just evenly incorporated into the dough.

Transfer the dough to an oiled container.

Ferment for 1.75 – 2 hours, with a fold after the first 45 minutes. The dough will increase about 50% in volume and be light and spongy, but without large gas bubbles.

Divide the dough into two equal pieces. Preshape the pieces into balls and let them rest, covered, for 30 minutes.

Shape the dough into balls. Roll the top of each ball on a wet towel to hydrate it, then in bran or seeds.

Place the loaves right-side-up in a couche. Slash each loaf about ½-inch deep, at a 90-degree angle to the loaf. Not too many slashes!

Proof, covered, for 45 minutes to one hour.

Meanwhile, preheat the oven, with baking stone, to 475F. Bake for 8 minutes with steam, and another 22 minutes or so without steam. Turn off the oven and leave the loaves in for another 10 minutes, with the door ajar for the last 5 minutes of this time.

Cool on a wire rack. Wait until completely cool to cut and eat; best if you can wait at least 12 hours.