Food writer Stefan Gates continues his quest to uncover the truth about those notorious food additives, E numbers. In this episode Stefan looks at E number preservatives. He discovers one that keeps deadly bacteria out of our bacon, one that can double up as an explosive, and he even discovers an E number that the entire human race can't live without. And in a true act of immersive reporting, Stefan even attempts to extract several E numbers from his own body. As if this weren't enough, he then rustles up a cake out of them. We're not making this up.