all the levain from aboveall the levain from above
50gwhole wheat flour
450gstrong bread flour
375gslightly warm water
10gfine sea salt
Instructions
Mix starter, flour, and water; let ripen 6-8 hours until bubbly and doubled.
Combine levain, water, and flours; knead into shaggy dough, autolyse 1 hour.
Add salt, knead gently, and let rest 45 minutes. Optional lamination: stretch, fold, and shape dough into a bowl; refrigerate overnight.
Perform folds every 45 minutes for 3 rounds; let rise until puffy with bubbles, about 2 hours.
Shape dough into a log, place seam side up in a floured basket, cover, and refrigerate overnight.
Preheat oven to 475°F with Dutch oven inside. Transfer dough onto parchment, score, and bake covered 25 min, then uncovered 20 min at 450°F. Cool 2 hours before slicing.
Notes
Use a banneton or bowl lined with floured towel for proofing.