This New England classic is adapted from the baked beans served at Boston's famous Durgin-Park restaurant.
Soak beans overnight in cold water. When you're ready to cook, place beans in a heavy saucepan; fill with water to cover by about a half inch. Boil 25-30 minutes, until just tender; don't overcook. (Pick up a bean between thumb and forefinger and pinch; the outer shell should slip off.) Drain and rinse, reserving the liquid.
Preheat oven to 400°. Place half the salt pork in the bottom of a large ovenproof pot. Add beans, sugar, molasses, dry mustard, white pepper, salt, and reserved liquid. Top with remaining salt pork. Cover and bake 4 to 4-½ hours. Stir occasionally and add more water as needed. Let beans rest 30 minutes before serving.