For the final dough:
• 250 grams sourdough (see above)
• flax seed soaker (see above)
• 280 grams organic white bread flour
• 280 grams organic spelt flour
• 400 grams water
• 14 grams coarse sea salt
Mix starter, cover and let sit overnight (eight to 12 hours) at room temperature of about 75 F. Pour the flax seeds into a separate bowl and just barely cover with water, then cover the bowl. By the morning, the flax seeds will have absorbed all the water. (In a pinch, even two hours of soaking will do.) Ideally, the starter will have risen fully and then just started to deflate.
Combine the starter and water in a bowl and mix it up with a wooden spoon or spatula until combined. Add the flours and using a plastic bench scraper, spoon, or mixer with dough hook, mix the dough until all the lumps of flour are gone. This will take about two minutes. Cover and let rest for 20 minutes.
Add salt and mix on a slow speed, about four minutes. If kneading by hand, do so until the salt is mixed throughout and the dough is starting to take on a smooth appearance, about five minutes. Add the flax seed soaker and using your hands or the mixer, continue mixing until the seeds are evenly distributed.
Form into a ball and place in a clean, oiled bowl and cover for the first rise. Assuming the temperature is around 75 F, turn the dough out onto the counter and fold it at 50 minutes. (See video of technique here.) Be careful not to tear the skin of the dough. Fold again at another 50 minutes. Let it rest for another 50 minutes, for a total rise of two and a half hours.
Turn the dough out on a lightly floured counter, divide in two and form into rough batards or boules. Let rest for 15 minutes, then finish shaping the loaves. Place them in a floured towel inside a bowl, or a floured couche for batards and cover with a towel or plastic wrap.
The final rise should take 90 minutes. Or, to build up the flavor of the loaf, cover the loaves then let them sit for 30 minutes before putting them in the refrigerator in a closed plastic bag. (I use Ziploc Big Bags.) Retard the loaves for eight to 12 hours, or longer if you want a pronounced sour flavor.
When ready to bake, check the loaves. They should have risen by about 75 percent. If they have risen sufficiently in the refrigerator, keep them there until baking. Otherwise, remove one loaf and let it rise at room temperature for another hour as the oven is preheating.Turn the oven to 460 F with a baking stone in the middle of the oven and a rimmed sheet pan on the bottom. Preheat for at least one hour.
When ready to bake, slash the loaf in a square pattern with a bread knife or blade, then place in the oven on the heated stone. (Batards can be slashed lengthwise.) Pour two-thirds cup of water into the sheet pan and close the door. Bake for 30 minutes. Turn down the oven to 420 F and keep baking for another 15 minutes. Check the loaf. It is done when you rasp it on the bottom with your knuckle and it makes a distinct hollow sound. If not yet done, turn down oven to 400 F and keep baking for 10 minutes. Then turn off the oven, open the door slightly and let the loaf sit for another 10 minutes. Repeat with the second loaf.
Allow the loaf to cool for at least one hour before cutting it open.
To read more about the process and thinking behind Sam's whole-grain sourdough, click here.