Makes 2 loaves
The day before baking the loaves:
Make the levain: Mix levain ingredients in a container, making sure it is mixed well and no dry flour is visible, then loosely cover and put in a draft-free, warm place, letting it mature for 4 hours.
After 3 hours, from the main dough ingredients, mix the flours and 640g of water in a bowl, making sure there are no dry flour spots. Cover and put in same draft-free place as the maturing levain. This process is called autolyse.
When the levain has matured, uncover the flour and water mixture and pour the levain, the remaining 50g of water, and the salt into it. Mix well for about 2-3 minutes, making sure all of the ingredients are incorporated together. Place in a bowl and cover. The dough needs to ferment for 4 hours, covered, in a warm, draft-free place. The dough needs 4 turns* every 30 minutes, starting at 30 minutes after you first put it to rest. After the folds, leave the dough for the remainder of the bulk fermentation.
After the 4 hour bulk fermentation, turn dough out onto a lightly floured surface. Divide into two using your bench scraper. Shape the dough into rounds by pulling the dough towards you lightly, then rotating slightly and pulling the dough towards you again, as you turn the dough into a round shape, making sure you build enough surface tension on the top, without tearing it. Let it rest for 30 minutes, uncovered.
After 30 minutes have elapsed, lightly flour the surface of the dough rounds, then lightly flour your work surface. Working one round at a time, flip the dough round onto the work surface. Lightly stretch the dough out at the bottom (the side nearest you), then both sides. Pull the bottom up and fold a third of the way up the dough. Then grab the sides and fold onto each other, like when one folds a t-shirt. Lastly, grab the top part of the dough (farthest away from you) and fold down a third of the way. Flip the dough and gently cup and pull the sides of the dough onto the bottom, creating more tension on the surface. Place the dough, seam side up, into your bowl or bread basket for overnight proofing. Repeat for the remaining dough. Cover the dough with plastic and place in the refrigerator overnight.
Build your fire in the Cru oven.
*To turn the dough: Take one section of the dough farthest away from you in the bowl, gently pull up and over, towards you, much like folding the dough in half towards you. Then turn the bowl 180° and repeat. Now turn the bowl 90° and do the same fold. For the last fold, turn the bowl 180° and repeat.
You should lite your oven when you are ready to bake the bread. Once lit continue to feed the fire. You want a robust fire that will break down the wood into coals. Keep feeding fire until you attain approximately 700F. Leaving the door off monitor temperature until temperature decrease to about 600-650F. Scrape coals as far as possible into the back of the oven (see photo). Place dough on your peel and launch into your oven with the goal of place the dough in the center of the stone but as far back from the coals as possible. Close oven opening using the full size oven door. Bake approximately 30-40 minutes rotating approximately every 6 to 10 minutes. For second loaf scrape the coals away from the back of the oven and spread them over the middle oven the stone. Add some small and medium sized pieces to the coals and reignite fire (you may have to blow on the coals or add some bark, ect.). Add several more smaller pieces of wood as they these will breakdown into coals faster than larger pieces. Keep the fire burning robustly to break down the wood into coals as fast as possible. Once the oven is at temperature scrape the coals as far back as possible and repeat the above baking process.
Baking Notes - bread typically bakes faster in wood fired ovens so all times are approximate. Monitor bread frequently to prevent burning. If over browning cover bread with aluminum foil.