Feed your sourdough starter and leave it at room temperature to double in size within 6 hours. If using refrigerated starter fed within the last 7 days, it can be used cold without feeding. The starter should be at or just past its peak activity for best fermentation.

Using a kitchen scale, weigh flour into a medium bowl, then add salt, spices, and optional seeds. In a separate small bowl, mix starter and water until cloudy and well combined. Pour starter-water into flour and mix with a fork or wooden spoon until a thick, shaggy, sticky dough forms. Cover and rest 15 minutes.

With a wet hand, pull and stretch the dough upward and fold it over its center, turning the bowl quarter turn and repeating this 3-4 times for about 30 seconds until dough feels firm. Cover and rest 15 minutes, then repeat this stretch and fold once more.

Cover the dough bowl with plastic wrap, wax wrap, or damp towel, and proof at room temperature (68-70°F ideal) for 8-12 hours. Adjust duration based on ambient temperature—warmer environments require less time, colder require longer.

Dough should be noticeably expanded with a slight springy dome. Perform the poke test to check readiness. Line a high-sided bowl with parchment or rice-floured banneton. Loosen dough from bowl edges, lift and stretch it vertically 1-2 feet, then fold onto itself multiple times with wet hands, turning the bowl between stretches. Perform up to three stretches with resting intervals. Transfer dough to prepared bowl or banneton, seam side up if proofing basket is used, sprinkle with seeds and rice flour.

Place shaped dough uncovered in the refrigerator for 1 hour (or up to 3-4 hours for delayed baking) to cold-proof and firm up for better scoring and oven spring. Meanwhile, preheat oven fully to 500°F for 1 hour with a Dutch oven inside and lid on. Use convection if available.

Carefully remove dough and Dutch oven from fridge and oven lids. Score dough swiftly with a sharp blade at a 45-degree angle about 3/4 to 1 inch deep. Lift parchment with dough and place directly into hot Dutch oven, cover immediately. Bake at 500°F with convection for 20 minutes (or 25 minutes without convection), then remove lid, reduce temperature to 450°F and bake uncovered for another 10-15 minutes until deeply golden and internal temperature reaches 204-208°F.

Remove loaf from Dutch oven and cool on a rack or tilted on its side for 1 hour before slicing to preserve crumb texture. Serve toasted with butter, ghee, olive oil, or toppings like mashed avocado or jam.

Store wrapped in a kitchen towel for 1-2 days to maintain crust crispness, then transfer to a zip-lock or waxed bread bag to keep moist longer. Sourdough slices can be frozen. Leftover bread can be used to make croutons.