As with much of wine chemistry involving oxidation (“and reductive chemistry is even worse”, quips Milanowski), we are still far from a full understanding of what makes glutathione tick. And better yet, as the Plumpton College lecturer points out, certain research papers aimed at determining the role and mechanisms of glutathione have concluded that some of the action attributed to that wonderful tripeptide could actually come from… other, as yet unidentified compounds. Yet another example of what makes wine so complex and fascinating, both in making it and drinking it.