Since 2000, Wakefield has led the early adoption of the screwcap closure, a trend which gained momentum here in the Clare Valley before taking over the (mainly southern and new) world of wine.
In mid-2000, we joined with fellow Clare Valley winemakers for a meeting at the classic Rising Sun Hotel and a historic decision was made. After a long night of conversation which centred on the shortcomings of the cork closure (and a few glasses of wine), the Clare Valley winemakers agreed to initiate what would be a game-changing move, to bottle the region’s iconic riesling under screwcap.
In 2004 we moved to seal all our wines under screwcap— the first major winery in Australia to do so. More than a decade on, screwcap closures now account for more than 90% of current vintage Australian wine.
The problem with cork
Sadly, there has been many a great wine ruined by cork taint. Most well informed sources agree that at least three percent of wine is affected – probably more. Cork taint, a problem commonly caused by a compound known as TCA (its chemical name is 2, 4, 6 trichloroanisole) is produced by a fungus in the cork developing inside the closure and infusing the wine with a smell that many describe as similar to the smell of wet cardboard and can destroy the taste and aroma of the wine. An equally serious issue for a wine is the potential for 'random oxidation' due to the inherent variability of cork’s oxygen barrier. On the other hand when storing wines under screwcap, the food-grade polymer seal in the cap can virtually eliminate outside air contact, preventing not only leakage but eliminating spoilage due to cork taint.
Effects on ageing
Storing wines under screwcap, still allows wines to develop and the flavours mature, though many believe it will be at a slower, more controlled rate. Wines age as a result of not only that small amount of air that enters the bottle through the cork. Many of the changes in a wine occur without the presence of oxygen, so will continue unaffected.
This in turn means there will be far less variation in wine quality from one bottle to another. Storing wines under a screwcap means you can leave them standing upright or lying down. Normally the only reason to lay bottles down is to keep the cork from drying out. So storing wines under screwcap can offer greater flexibility in where and how you locate your cellar.