In a big bowl, add 124 g of whole wheat flour. Then, hydrate it with the 284 g of room temperature yeast water.
Combine well to incorporate water into the flour and make sure it is well combined with no dry flour patches.
Cover it and let it ferment until it doubles up. Mine took about 4 hours. The exact time will depend on your ambient kitchen temperature and the vigor of yeast water. So, watch the levain for the rise. It should become a bit bubbly.
Now, combine the rest of the flour, water, and salt. Mix with the back of a wooden spatula until everything comes together and becomes a dough. Use hands towards the end if needed.
Cover with a cling wrap or a kitchen towel. Let the dough cold rise in the refrigerator overnight. (Cold fermentation helps with gluten development process)
By the next morning, the dough would have doubled in volume. Take it out of the fridge and remove it onto a flour-dusted work surface.
Dust your hands with some flour and collect the edges to pre-shape the dough. Collect the edges from sides and tuck them at the center over one another. Now grab the lower edge and fold it over the dough and flip the dough over in a way that it is resting on the surface with all the seams facing down.
Let the dough rest for 5 minutes. Before doing the final shaping.
For shaping the dough, dust your hands and the work surface around the resting dough with some flour. Flip the dough with the seam sides now facing you.
Stretch the edges outward and tuck them one over the other. Now grab the lower edge, stretch toward yourself and tuck it at the center. Repeat the same with the top edge. Now, gently flip the dough.
Using your hands pull the dough gently toward you, to build tension on the surface. Rotate the dough, 90 degrees, and again pull towards yourself.
Now using a dough scraper, gently lift the dough and flip into a proofing basket or a bowl with flour-dusted linen.
Let the dough proof until it doubles in size.
Preheat the oven to 500 0F with a Dutch oven placed inside.
Gently transfer the dough onto parchment paper. I like to put a slash on the loaf, to prevent uneven cracking all over the surface and also give the bread some guide to rise along.
Bake covered for 20 minutes at 450 0F. Remove the lid and bake for another 20-22 minutes until the loaf becomes brown.
Let the loaf cool completely before slicing.