The OTR spread of the natural cork supports the observation that the best natural corks are brilliant for the wine but the worst natural corks, over time, oxidize and destroy the wine’s natural fruit characters.
The OTR spread of the ProCork product supports the theory that the oxygen selective membrane turns high OTR corks into good OTR corks, thus improving consistency across bottles including the retention of natural fruit character and SO2 as demonstrated in further independent scientific wine trials (shown below).
The selective permeation technology relies on size exclusion. Large molecules like cork tannins, taints, adhesive chemicals used in agglomerated and colmated corks, and even water etc are blocked from passing through the sieve while small linear molecules like oxygen can pass at a slow rate. In this way the cork can still "breathe" while blocking taints.
The improved OTR (oxygen transmission rate) is actually a result of decreasing the OTR of the high permeability corks but leaving low permeability corks unchanged. This can be seen with the measurement of OTR spread (as shown below).