Boar’s Head announced Friday that liverwurst and the plant that made it are gone forever. The company has been battling a recall linked to an outbreak of listeria. According to the federal Centers for Disease Control and Prevention, the outbreak led to at least nine known deaths and 57 cases across 18 states. The CDC traces the outbreak to liverwurst, which was made at the Jarratt, Virginia, plant operated by Boar’s Head. Boar’s Head reported Friday that “our investigation has identified the root cause of the contamination as a specific production process that only existed at the Jarratt facil…