The next day, place the beans in a pot with fresh water and bring to a boil over medium-high heat. Do not add salt—the smoked pork will provide enough salt. Lightly crush the carnations, allspice grains, and juniper berries with a mortar. Place them in a tea filter bag along with the bay leaves and add to the pot.
After 1 hour of cooking, add the smoked pork belly. Reduce heat to medium and cook for 45-60 minutes, adding more water as needed if the liquid level drops.
Remove the pork belly and set aside. Season the bean liquid with the sugar and wine vinegar. Dissolve the cornstarch in a small amount of cold water and stir into the boiling liquid. Cook for 2 minutes, stirring often, until thickened. Return the pork to the pot and remove the tea bag with spices.