- 8 ounces old dough or sourdough starter
- 10 1/2 ounces unbleached all-purpose flour
- 11 ounces unbleached bread flour or high-gluten flour
- 1 ounce spelt flour
- 3 1/4 teaspoons kosher salt
- 1 teaspoon instant yeast
- 1 3/4 cups cool water
- 1/8 cup extra virgin olive oil
Combine all ingredients in a large metal bowl. Work with the paddle attachment of a stand mixer or by hand until flour absorbs all liquid, forms a coarse ball, and begins to strengthen, about 3 minutes. Let rest 5 minutes. Continue to work until soft, supple, and only slightly sticky, about 3 minutes. The dough should pass the windowpane test. You may have to incorporate more flour or water to achieve this texture, depending on the hydration of the old dough.
Form dough into a ball by repeatedly folding in corners until surface tension develops. Oil a large bowl and roll ball of dough all over to coat with oil. Cover bowl with plastic wrap. Let rise at room temperature for 1 1/2 hours. Punch down dough, re-form into a ball, and refrigerate for at least 2 hours, or until ready to use.