For the beans:
8 cups water
2 1/2 tablespoons salt, divided
1 pound dried cannellini beans

For the soup:
1/2 pound (5 to 6 pieces) thick-cut bacon , diced (or substitute 1 tablespoon olive oil for vegetarian version)
2 large yellow onions, diced
3 celery stalks, diced
4 garlic cloves, minced
1 cup white wine or water
1 bay leaf
1/2 pound pasta
5 thyme sprigs
10 ounces baby spinach
2 teaspoons salt
Pepper to taste