As the primary election season heats up, a different kind of debate is taking shape in Yakima Valley’s wine country:
Do you close a wine bottle with a cork or a screwcap?
The Hogue Cellars, a Prosser winery, recently made a case for screwcaps with the release of a five-year study showing that wines topped with a screwcap taste as good or better over time than wines topped with natural cork or other closures.
The study backed up Hogue’s decision to use screwcaps for all its wines, including its higher-priced reserved wines, beginning with its 2009 vintage.
While the study was done in-house, the winery underwent years of blind testing under an extensive research criteria to ensure it received sufficient scientific data to prove there was a difference between the different closures, said Co Dinn, Hogue’s director of winemaking.
“Not only will (the wine) be preserved, our outlook is that they will continue to age well,” he said.
While many in the wine industry locally and statewide praised Hogue’s research efforts, the study is not likely to settle the ongoing debate.
“What they’re doing is best for them, but I’m not sure if it’s the answer for everybody,” said Mike Januik, winemaker and owner of Januik Winery in Woodinville.
There are no hard and fast figures on the market share of different closures.
But there is one thing not up for debate: The majority of wine bottles are closed with a cork, while screwcaps and synthetic corks follow the leader.
Screwcaps have been commercialized since the 1970s, but momentum for the closure took shape more than a decade ago after reports of what is known as cork taint — when a chemical substance called TCA develops in the cork and negatively alters the flavor and taste of the wine.
A variety of studies done in the past decade report 5 percent to 7 percent of bottles topped with traditional corks could be affected.
As a result, more wineries took a look at screwcaps.
In 2004, The Hogue Cellars, frustrated with throwing out a percentage of its wines from cork taint and dealing with an ineffective seal with synthetic cork, completed a 30-month study on wine closures.
That initial study showed that the screwcap best preserved the flavor of their wines.
Based on that study, Hogue began topping 70 percent of its wines — all but its higher-priced reserved red wines — with a screwcap.
Along with affirming the results of the earlier study, Hogue’s newest study focused more on how red wines age long-term with a screwcap closure.
To do so, it compared two merlot wines under a variety of closures, including cork, over a five-year period. It measured the quality of the wine on several criteria by conducting an in-house blind tasting by a professionally trained panel, made up of staff from Hogue’s winemaking, production and enology teams, every 12 months.
The study uncovered a crucial point: The liner, which separates the wine from the aluminum screwcap, is key in the wine’s aging.
Hogue found that a liner made with Saranex, a film developed by the Dow Chemical Co., let in enough oxygen for the wine to age well while preserving the wine’s fruity flavors.
The study also notes that the same liner better preserved the fruity flavor of sauvignon blanc, a more oxygen-sensitive white wine.
Screwcaps with a tin liner, for example, did not let in any oxygen, causing a gunpowder-like taste over time. Bottles closed with a synthetic cork let too much oxygen in, causing a decline in wine quality over time.
“We wanted a little air,” Dinn said. “Not too much, not too little.”
After seemingly in decline just a decade ago, cork has made a comeback of sorts.
In the last two years, cork has gained more fans, including environmentalists, who claim corks are more sustainable, and sommeliers who think corks provide a better tasting experience.
Cork manufacturers also have been aggressive in improving their quality control process to ensure that corks with TCA are not delivered and used by wineries, said George M. Taber, author of “To Cork or Not to Cork: Tradition, Romance, Science and the Battle for the Wine Bottle.”
Taber, quoting a study from Christian Butzke, a professor at Purdue University in Indiana, said cork taint is so rare — less than 1 percent, according to many estimates — that an average wine consumer will go a lifetime without opening a tainted bottle.
“(Cork manufacturers) spent a lot on research. They spent a lot of money on improving their manufacturing and getting rid of the chemical problem,” he said.
With that issue dying down, many wineries remain firm about their decision to keep using cork, especially with the persistent perception that wines with screwcaps are lower priced and of lower quality.
“That’s the ultimate question: Will people pay the same amount of money for a screwcap wine as for a corked wine?” said Jim Harbertson, associate professor at Washington State University in Prosser.
That perception is a driving factor for Ste. Michelle Wine Estates to keep using cork for most of its wines, said Jan Barnes, the company’s vice president of marketing.
Some of Ste. Michelle’s brands offer a limited number of bottles with a screwcap. But it hasn’t prompted consumers to demand the closure for other varieties, she said.
That means cork will still be the main closer with most of its wines, Barnes said.
But the screwcap still has plenty of fans.
All the white wines at Thurston Wolfe Winery in Prosser are closed with a screwcap.
Winemaker Wade Wolfe, who worked at Hogue Cellars during its first study, said screwcaps provide more consistency. While the cork taint issue has died down, cork still can impart other unwelcome flavors into to the wine, he said.
“I think in the last decade, the screwcap has proven its value as a valid closure to give you an optimized quality of wine,” he said.
Like Democrats and Republicans, Red Sox and Yankees and Cougars and Huskies, corks and screwcaps are more likely to co-exist than declare complete victory.
“They all have their strong sides and their weaknesses,” Taber said. “There’s no perfect closures and I don’t think there ever will be.”
Dinn, Hogue’s director of winemaking, acknowledged that he’s not expecting to change the cork die-hards.
Still, he believes his winery’s study might persuade wineries who are undecided on the issue.
“The best we can do to move the needle is to put the information out there,” he said.