Combine salt pork or bacon and water in a heavy-bottomed stock pot or Dutch oven over medium heat and cook, stirring occasionally, until water has evaporated and pork has begun to brown and crisp in spots, about 8 minutes. Add onion, and celery. Season gently with salt and pepper and continue to cook, stirring occasionally, until onions are softened but not browned, about 4 minutes longer. Add flour and cook, stirring, until no pockets of raw flour remain. Stir in clam juice, followed by milk. Add potatoes and bay leaf and bring to a simmer.
