Step 1

Mix: In a large bowl, combine 100g active sourdough starter and 350g warm filtered water. Stir until the starter dissolves and the water looks milky. Then add 480g unbleached bread flour, 20g dark rye flour (or all 500g unbleached flour), and 10g sea salt. Mix until you have a shaggy dough. If it seems too dry, add a tiny bit of water at a time until it comes together. Cover and let rest for 1 hour.

Step 2

Stretch & Folds: After the dough has rested, perform four rounds of stretch and folds, 30 minutes apart: With wet hands, grab one side of the dough, stretch it up, and fold it over itself. Rotate the bowl and repeat on all four sides. Cover and let rest for 30 minutes.Repeat this process four times total.

Step 3

Bulk Fermentation- Let your dough rise on the counter until doubled in size, bubbly, and jiggly. The timing depends on your dough temperature and starts in step 1 when you mixed your dough.80°F (27°C) → ~5-6 hours75°F (24°C) → ~7-8 hours70°F (21°C) → ~12 hours65°F (18°C) → ~16 hoursYou'll know your dough is done when you see these visual cues- Doubled in size, airy, bubbly, and jiggly.

Step 4

Shape the Dough & Coat with Sunflower Seeds: Once your dough is ready Pre-shape: Gently turn it out onto a clean surface. Using wet hands and a wet bench scraper, shape it into a round loaf getting tension in the top of the dough. Let it rest for 30 minutes to relax the gluten.Final shape: Flip dough smooth side down, stretch into a small square, fold the bottom half into the middle of the dough and the top half into the middle as well. Rotate dough and roll into a log shape.Spray the top of the dough with water. Flip it upside down onto a plate of about 1/3 cup sunflower seeds, rolling it to coat the surface evenly. Place it seed-side down into a well-floured banneton basket. Stitch up the dough slightly to create a better structure and oven spring.

Step 5

Final Proof- You have two options:Cold proof (Recommended for better flavor & handling): Cover and refrigerate overnight (or up to 24 hours).Room temperature proof: Let it rise for 2 more hours, then bake immediately.

Step 6

Bake: Preheat your oven to 450°F (232°C) with a Dutch oven inside for 30 minutes. Take your dough out of the fridge and flip it onto a piece of parchment paper or a silicon sling. Score the top with a sharp knife or bread lame. Carefully place the dough into the hot Dutch oven. Bake covered for 30 minutes, then uncovered for 15 minutes.

Step 7

Remove from the oven and let it cool on a rack for at least 2-3 hours before slicing. Cutting too soon can lead to a gummy texture.