Methods/steps

1. Rinse the beans in a colander and sort through them to remove any small stones or foreign matter.  Transfer them to a large bowl, add enough water to cover them by two inches and soak them overnight.  After soaking, discard any "floaters" and drain the beans.
2. Preheat the oven to 300 degrees.
3. Cook the bacon in a 5- to 6-quart Dutch oven over medium-high heat until it is browned. Remove the pot from the heat and transfer the bacon to a mixing bowl.  Add the mustard, Worcestershire sauce, molasses, brown sugar, and tomato sauce, stir to combine, and set aside.
4. Drain all but about 3 tablespoons of fat from the pot, and place it over medium heat.  Add the onions and sauté until they are translucent, about 5 minutes.  Add the garlic and cook for another 2 minutes.
5. Add the diluted Glace de Viande Gold® and the beans, stirring and scraping the browned bits from the bottom of the pan.  Bring the mixture to a simmer, cover the pot, and transfer it to the oven.  Bake the beans for 45-60 minutes, until they are tender enough to bite into, but still firm and slightly mealy.
6. Stir in the reserved barbecue sauce and bacon mixture and return the pot to the oven uncovered.  Bake until the beans are completely tender, 30 to 60 minutes.
7. Cool the beans to room temperature, cover the pot, and refrigerate overnight.
8. To finish, bring the beans to a simmer, uncovered, over medium heat.  Reduce the heat to low and simmer, stirring occasionally, until the liquid has reduced and thickened to the consistency you want, about 40 to 60 minutes (or longer, depending on how thick you like the sauce).  Stir in the vinegar and season to taste with salt and pepper.