4 ounces salt pork, trimmed of rind and cut into ½-inch cubes
2 ounces bacon, cut into ¼-inch pieces
1 medium onion, finely chopped
½ cup + 1 tablespoon mild molasses, divided
1/3 cup light brown sugar
2 tablespoons brown mustard
1 pound dried small white beans (like great northern beans), rinsed and picked over
1¼ teaspoons salt
9 cups water
1 teaspoon apple cider vinegar
Salt and pepper, to taste
1. Adjust oven rack to lower-middle position; preheat oven to 300 degrees F.
2. Add salt pork and bacon to a large Dutch oven (at least 7 quarts); cook over medium heat, stirring occasionally, until lightly browned and most fat is rendered, about 7 minutes. Add onion and continue to cook, stirring occasionally, until onion is softened, about 8 minutes.
3. Add ½ cup molasses, brown sugar, mustard, beans, 1¼ teaspoons salt, and 9 cups water; increase heat to medium-high and bring to boil. Cover pot and set in oven. Bake until beans are tender, about 4 hours, stirring once after 2 hours.
4. Remove lid and continue to bake until liquid has thickened to syrupy consistency, 1 to 1½ hours longer. Remove beans from oven; stir in remaining tablespoon of molasses, vinegar, and additional salt and pepper to taste. Serve. (You can make the beans ahead of time, letting them cool to room temperature, and then storing in an airtight container in the refrigerator for up to 4 days.)