510 g organic unbleached bread flour
57 g organic whole-wheat flour or whole-wheat spelt flour
9 g kosher or sea salt
22 g (1/4 cup) King Arthur Flour Baker’s Special Dried Milk (optional)
28 g pepitas (optional)
28 g sunflower seeds (optional)
227 to 255 g cooked pureed pumpkin
283 to 340 g pumpkin-cooking water, whey from yogurt, whey from cheesemaking such as ricotta, or water, or a mixture
28 to 43 g fresh sourdough starter
In a large (3-quart) bowl, stir together the bread flour, whole-wheat flour, salt, and optional ingredients if you choose to use them.
Make a well in the center and pour in the pumpkin puree, about 3/4 of the liquid, and the sourdough starter. Begin mixing the ingredients into a dough with a wooden spoon, switching to a bowl scraper when the dough gets too tough to handle with the spoon. Add more liquid, little by little, to make a fairly wet dough. Cover the bowl with plastic wrap and leave on the counter for 15 minutes or up to 1 hour. Fold the dough over on itself, rotating the bowl as you dig under the dough and pull up and over the mass with your rubber bowl scraper. This will incorporate any bits of unmixed flour into your dough. Recover and repeat the resting-folding process twice more. If time is short, do one fold, go out to do your errands, and do another fold or two when you return. The bread will be fine whatever you choose.
After the folds, set the covered dough aside on the counter to rise until the dough is very bubbly on top and nearly fills the bowl, 18 to 24 hours depending on how warm the kitchen and the liveliness of your starter.
Turn the dough out onto a well-floured board, flour the top, and then fold the dough over on itself like an envelope: right to center, left to center, top to center, bottom to center. Repeat. Flip seam-side down, cover with the bowl, and let rest 15 minutes.
Spread a proofing cloth on a cutting board. Dust the cloth very lightly with flour and heavily with polenta. Gently shape the dough into a ball and place, seam-side down, on the prepared proofing cloth. Top with more polenta, cover with the cloth, and place the dough on the board into a plastic bag. Let proof 60 to 90 minutes.
Meanwhile, preheat the oven to 500°F. Put a heavy, covered casserole such as a cast-iron Dutch oven in the oven to preheat as well. Make sure the oven is blasting hot. It is very helpful to keep one or more baking stones in the oven.
Working quickly to retain all the heat you’ve built up, use very thick hot pads to remove the pot from the oven and set the lid aside. Gently turn the dough into the hot pot making sure it is now seam-side up. (As the dough bakes it will open along these ragged seams to give a terrific rustic look.) Shake the pot so the dough rolls around the pot and isn’t sticking to the sides. Recover the pot and place in the oven. Lower the heat to 475°F (or to 425°F if your bread is more than 10% whole-grain flour).
Bake 30 minutes. Uncover the pot and bake until the loaf is a crusty and medium brown, another 20 to 30 minutes. Let cool on a rack.
If you have any of the pumpkin’s juices or the cooking water left after cooking the pumpkin, use it as the liquid in the bread.
You can vary your add-ins depending on whim and what you happen to have on hand. I’ve used as much as 7 ounces combined rye and whole-wheat flour, added dried milk powder, flax seed meal, oat bran, pepitas, and sunflower seeds. Lately, I’ve retreated to just 10% whole-wheat flour and left out the dried milk in pursuit of a lighter, more robustly flavored bread.
See the multigrain no-knead bread and variations for more detailed mixing and baking instructions.