Ensure your sourdough starter is active and bubbly (fed 4–12 hours before mixing).
In a bowl, combine flours, water, starter, honey, and oil. Mix until no dry flour remains. Cover and let rest (autolyse) for 30 minutes.
Sprinkle salt over the dough and mix thoroughly (by hand or stand mixer).
Cover and let rise at room temperature (70–75°F) for 6–10 hours, folding the dough 2–3 times in the first 2 hours to strengthen gluten.
Gently shape the dough into a log and place into a greased loaf pan. Cover with a damp towel.
Let rise 1–3 hours at room temperature OR refrigerate overnight (for deeper flavor).
Preheat oven to 375°F (190°C). Bake for 35–40 minutes until golden brown and internal temperature reaches 200°F (93°C).
Let cool completely (1–2 hours) before slicing to avoid a gummy texture.