Add the beans to a large bowl and cover with water. Soak for 8 hours or overnight, then drain.
Heat oven to 350ºF (180ºC). Heat a large Dutch oven or heavy bottomed pot with a lid over medium heat, add the bacon and cook until fat has rendered and almost crispy, about 5 minutes.
Add the onions and garlic, sautéing until tender, about an additional 5 minutes.
Add the soaked beans, ketchup, maple syrup, brown sugar, apple cider vinegar, mustard powder and Worcestershire sauce.
Cover with 8 cups (1.9L) of water. Bring the mixture to a boil over medium-high heat then transfer the Dutch oven from the stovetop to the oven. Season generously with salt and pepper.
Bake, uncovered, until the sauce thickens and the beans are tender but not falling apart, stirring occasionally, about 4 hours. If needed add enough water to keep the beans just covered, 1 cup (240g) at a time.