Dissolve salt in cold water in a large bowl. Add beans, soak 8-24 hours, then drain and rinse.
In a Dutch oven over medium heat, cook bacon until browned, 5-8 minutes. Add onion, bell pepper, and celery; cook until soft, 6-7 minutes. Stir in garlic, thyme, paprika, bay leaves, cayenne, and black pepper; cook 30 seconds.
Add beans, broth, and water. Bring to boil, reduce to a lively simmer. Cook, stirring occasionally, 45-60 minutes until beans tenderize and liquid thickens slightly.
Add sausage and red wine vinegar. Continue cooking until beans are fully tender, sauce thickens to creamy, about 30 minutes. Adjust seasoning with salt, pepper, and vinegar.
Serve beans over white rice, garnish with scallions. Hot sauce optional.