Ingredients:

  • 50g active sourdough starter (fed within 4-6 hours)
  • 500g bread flour (divided: 50g for levain, 450g for dough)
  • 50g whole wheat flour
  • 390g warm water (divided: 50g at 85°F, 340g at 90°F)
  • 10g fine sea salt

Instructions:

  1. Build the Levain: Mix 50g active starter, 50g bread flour, and 50g warm water (85°F) in a jar. Let sit in a warm spot until tripled in size, approximately 4 hours.
  2. Mix the Dough: In a large bowl, whisk 340g warm water (90°F) with the active levain until milky. Add 450g bread flour, 50g whole wheat flour, and 10g fine sea salt. Mix by hand until a shaggy mass forms.
  3. Develop Gluten: Perform 4 sets of 'Stretch and Folds' every 20 minutes over the course of 80 minutes to build dough strength.
  4. Bulk Fermentation: Cover and let the dough rest in a warm spot (75°F–80°F) until it grows by 50% in volume and shows visible surface bubbles (approx. 4–5 hours).
  5. Shape: Gently tip dough onto a floured surface. Fold edges into the center to create a round boule. Tension the surface by dragging it against the counter.
  6. Cold Retard: Place shaped dough into a proofing basket, cover, and refrigerate for 8–15 hours.
  7. Bake: Preheat a 5-6 quart Dutch oven. Score the loaf and bake at 450°F (230°C) for 45 minutes total (covered for the first 20 minutes to trap steam).