The night before serving, rinse the beans picking out any bad ones and place in a large bowl. Cover with water, add a pinch of baking soda and let soak at least 12 hours. The next day, drain well, and place the beans in a heavy stock pot with the vegetables and rosemary and bring to a boil. Reduce the heat to a simmer and cook until the beans are tender, about 1 hour. Drain, remove the vegetables and rosemary sprig. Place the beans in a large bowl and dress with the remaining ingredients while still warm. Taste, and adjust seasonings and vinegar as needed. Toss well, and serve at room temperature.