Oxygen not necessary for ageing bottled wine

Oxygen plays no important part in the ageing of bottled wine, an Australian study has found.

Earlier this month Southcorp’s research & development winemaker Allen Hart announced the results of different sets of research: Southcorp trials running since 1997, and trials conducted in collaboration with the Australian Wine Research Institute.

Both projects tested closures of varying permeability. The AWRI experimented on premium red wine sealed with varying closures and filled to different ullages of air space.

Hart’s conclusion, published in Wine Business Communications, was that oxygen is not ‘a vital component for the ongoing evolution and maturation of these red wines after bottling.’

The studies found that the evolution and maturation of wine would be accelerated with small but measurable amounts of oxygen entering via a closure, but that red wine continues to mature anaerobically without oxygen ingress through the closure.

He went on to say that wine aged anaerobically did show reductive characters, but not enough to affect the commercial acceptability of the wine.

Veteran Clare Valley winemaker Jeffrey Grosset, whose company Grosset Wines is involved with the grant-donating partners including the Australian Closure Fund (ACF), said that when this new research was added to the weight of existing evidence, ‘we can now say with a high degree of confidence, that oxygen is not necessary for ageing bottled wine, red or white.‘

Grosset added that ‘zero or low permeability closures’ are the obvious choice where quality is the priority.

He said that it was also evident that current synthetic and natural cork closures are too permeable and/or inconsistent to properly do the job of sealing the wine.

Written by Adam Lechmere