Recipe by Peter Endriss, Runner & Stone, Brooklyn, NYC
300g white bread flour
100g whole wheat bread flour
300g cold water
1g dry, instant yeast (osmotolerant if possible)
10g kosher salt
200g walnuts, raw, untoasted
Prepare levain with equal parts water and flour and 25 percent old starter 12 hours before mixing the dough. Leave to ferment at room temperature.
Mix together white bread flour, whole wheat flour, and cold water until combined and let sit for 30 minutes. Add all remaining ingredients except walnuts and mix on low speed until combined, and then medium speed for 1 minute to develop a little strength. Mix walnuts in on low speed just until combined.
Put dough in a lightly oiled bowl and let ferment at room temperature for 1-2 hours (longer if room is cooler, shorter if room is warm). Fold all four corners of the dough into the center and flip over in bowl. Cover and place in refrigerator for at least 12 hours, up to 24 hours.
Two hours before you’d like to bake, remove the dough from the refrigerator and allow to come to room temperature for 1 hour. Divide dough into 2 pieces (about 1 pound each) and shape into boules or batards. Place on floured board or sheet tray, cover and allow to proof for 1 hour. Halfway through the final proof (and 30 minutes before you’re ready to bake), preheat the oven to 450 degrees Fahrenheit with a baking stone on the lowest rack of the oven. Score loaves and place on stone. Throw a few pieces of ice onto the floor of the oven, quickly close the door (be careful for steam!) and bake for 20-30 minutes, to deep golden brown. Cool completely on wire racks before cutting and enjoying.
Note: This recipe has not been tested by the I Robbed a Farmer Kitchen