Horse bone needles play an essential part in assessing whether prosciutto is ageing properly and it meets the usual high standards. They are inserted by experts into different parts of prosciutto in a “piercing” process because they have a degree of sponginess that helps them to absorb the aroma of each part. Over time, they have become a hallmark of connoisseurs of genuine Prosciutto di San Daniele and a symbol of optimum ageing.