Place the beans in a large bowl and cover with cold water by 1-inch and cover with plastic wrap. Refrigerate overnight. Drain and rinse the beans and then drain again.
Place the beans in large pot with 2 quarts water, the onion, bay leaf, and peppercorns. Bring to a boil, then lower the heat and simmer for about 50 minutes, or until tender. A good test is to scoop up several beans in a spoon and blow on them: if the skin starts to peel off, they're done. Drain the beans, reserving the cooking liquid.
Preheat the oven to 225 degrees F.
In a small saucepan, whisk together the maple syrup, brown sugar, ketchup, chili paste, ginger, salt, and 1 1/2 cups of the cooking liquid, still reserving the remaining liquid. Bring to a simmer and cook over medium heat for 6 minutes.
Transfer the beans to a medium Dutch oven or a bean pot. Push half the bacon into the beans and place the rest on the top. Pour the maple syrup sauce over the beans. Place the lid on top and bake for 6 to 8 hours. Check occasionally; if the beans are too dry, add 1/2 cup more of the cooking liquid. If you like, you can remove the lid for the last 30 minutes to thicken the sauce. Discard the bay leaf. Serve hot.
