Sweet Potato Bread with California Raisins

1. Twelve (12) hours before final mixing, gently mix sponge ingredients together with bench scraper or wooden spoon until mixture forms shaggy dough. Cover with plastic wrap or damp towel and leave at room temperature (75˚F) for 12 hours.
2. Macerate raisins in warm water or orange juice (75°F) just to cover; soak for 12 hours. (Desired final macerated weight is approximately 72% raisins and 28% liquid.)
3. Cut sweet potatoes in half lengthwise; brush with oil and sprinkle with salt and pepper. Bake for 1 hour at 350˚F or until tender. Cool; peel and cut into 1/4-inch cubes. Set aside.

Final mixing:

1. Drain raisins, thoroughly. Weigh out final amount of macerated raisins. Set aside. 2
2. Break sponge into smaller pieces and place in bowl of spiral mixer. Add flour, water, milk, yeast, salt and butter; mix on 1st speed for 3 minutes. Add cooked, diced sweet potatoes and continue mixing for another 2 minutes. Then, increase to 2nd speed and beat 2 minutes longer.
3. With spiral mixer on 1st speed, fold in raisins and spices; mix until fully incorporated. (Desired dough temperature is 75°F. Do not over mix.)
4. Turn dough into large container; cover and allow to bulk ferment for 2 hours, folding dough after 1 hour.

Shaping:

1. Divide into four 17.7-ounce (500-gram) pieces. Pat out batards a little and point ends of dough to look like sweet potatoes. Place seam side up on a couche dusted with flour and proof for 1 hour.
2. Bake at 410˚F with steam for about 45 minutes, until done.