total package oxygen (TPO) is the awkward but efficient neologism used to refer to the total amount of oxygen that can influence the development, quality, and longevity of a wine once it has been bottled. It includes any oxygen that passes through the closure (see oxygen transmission rate), oxygen that diffuses out of the closure itself, oxygen in the head space, and dissolved oxygen in the wine. New non-destructive methods based on luminescence, as well as other destructive methods based on the use of dyes, have enabled the accurate measurement of TPO. It is clear that unless the pick up of oxygen throughout the winemaking and bottling processes is controlled, there is little point in stoppering the bottle with closures that are highly engineered to control oxygen ingress.
