The metal primarily used to make beer cans is aluminum. Aluminum is lightweight, resistant to corrosion, and has excellent barrier properties, making it ideal for preserving the freshness and flavor of beer. The use of aluminum for cans also allows for efficient recycling, as the material can be recycled indefinitely without losing its properties. Most beer cans are designed for easy opening and are coated on the inside to prevent the beer from coming into direct contact with the metal, which helps maintain the beer's taste. The widespread adoption of aluminum cans revolutionized beverage packaging.