Like any food product wine undergoes either aerobic or anaerobic aging depending on how much air is present. Both of these processes produce general flavour characteristics, independent of where the wine was made thereby effectively destroying the terroir driven characters of the wine. Aerobic aging browns the wine, alters fruit flavours to cooked fruit and jam flavours and with enough time flattens and dulls the wine. Anaerobic aging produces sulphides which also alters fruit flavours creating sulphury, cooked vegetable, swampy, cooked fruit and rubber flavours.

What is the optimum oxygen transmission zone and how does it help? It is the zone where there is enough air to stop anaerobic aging processes but not enough air for aerobic aging processes to be significant thereby protecting the terroir driven wine characteristics.

A major benefit of using ProCork’s specifically designed selective membrane technology with either natural cork or micro-agglomerated cork is that the oxygen transmission rate will always land in this optimum zone, where neither excessive anaerobic or aerobic aging will be predominate.

This has been demonstrated in two separate independent closure trials. In the red wine trial (shown above) the terroir driven red berry and cherry flavor was protected from alteration when the ProCork selective membrane technology was used. The OTR of the various closures was measured in the trial clearly demonstrating the optimum OTR zone which only the ProCork membrane landed in and it did so consistently. All the other closures including natural cork, agglomerated corks (including all the 1+1’s and micro-agglomerated corks), screw caps, plastic corks and glass stoppers all fell outside the optimum zone thereby losing the distinctive red berry and cherry characters for the more general cooked fruit or cooked vegetable characters.