The US winemaker Hogue Cellars today announced the results of a four-year study it has been conducting into the effect of five different closures on its wines.

The results, it said, showed that screw cap closures were proven to hold fruit and maintain freshness more effectively than natural and synthetic corks.

Jordan Ferrier, research enologist at The Hogue Cellars, will present the winery's extensive study today at the 55th annual American Society of Enology and Viticulture (ASEV) Conference in San Diego.

As a result of the study, Hogue will bottle its entire line of 2004 Fruit Forward wines - representing 70% of total production - in Stelvin screw caps with Saranex liners. The wines will be available in January 2005.

"After scientifically researching the effects of two kinds of screw caps, two brands of synthetic corks, and the traditional natural cork, we have come to the conclusion that Stelvin screw caps best preserve the quality of wine in the bottle," said David Forsyth, director of winemaking at The Hogue Cellars. "For us, it's all about delivering high-quality wines, and screw caps more effectively preserve the purity of the fruit and winemaking flavors with which the wines are meant to be enjoyed."

A panel of Hogue winemakers and trade professionals tasted and analyzed a 1999 Hogue Genesis Merlot and a 2000 Hogue Fruit Forward Chardonnay at six-month intervals for 30 months. Each wine was closed with natural cork, synthetic Neo cork, synthetic Supreme Corq, Stelvin screw cap with Etain liner, and Stelvin screw cap with Saranex liner.

The company said that at the conclusion of the study in December 2003, the following results were found:
The wines closed in natural corks showed low to medium levels of cork taint, while the synthetic and screw cap wines showed none.

Over time, synthetic closures began showing oxidation characteristics, leading to lower levels of fruit aromas and taste, as well as browning in both the Merlot and Chardonnay.

Screw cap closures maintained fruit, and the wines were considered less developed and relatively fresh for both red and white wines.

At both 24 and 30 months, screw caps were preferred over synthetics, which were preferred over the natural cork.

Screw caps and natural cork held SO2 better than the synthetic closures.

"Bottling our wines with screw caps will yield tremendous benefits: elimination of cork taint, as well as consistent and appropriate aging, lower SO2 levels at bottling, and greater ease in opening bottles," said Forsyth. "We are striving to reduce all barriers in delivering the quality of wines that consumers expect from Hogue."