Just screw it: Why WSU winemakers ditched cork for caps
When he founded the Blended Learning winemaking course three years ago, Thomas Henick-Kling had an important choice to make: How to seal his department’s student-created wines.
“For me, there was no question,” said Henick-Kling, director of Washington State University’s Viticulture and Enology program. “We were going to put them under screw caps.”
Traditional cork, with its iconic pop, lost out to the humble aluminum cap — and for good reasons.
“It’s the best technology for closing wine in a glass bottle,” said Henick-Kling, who is out to dispel old myths about caps being an inferior product typically used for cheap wine. He chose caps to avoid a common problem called cork taint.
“I’m a rationalist,” said Henick-Kling, explaining his decision. “It makes sense.”
For the past six years, every wine made by a WSU student or researcher has gone under screw cap.
Cork taint can wreck as many as seven bottles of wine out of a hundred. Tainted wines may have a moldy, musty, off-putting smell, or hardly any smell at all — either way, your sipping experience is ruined.“We’re not interested in dealing with cork-tainted wines,” said Jim Harbertson, WSU associate professor of enology.
Cork taint is mainly caused by two compounds, trichloroanisole and tribromoanisole, known as TCA and TBA. They develop anywhere that wood, water, chlorine and microorganisms combine. Even store-bought fruit can be ‘corky,’ says Henick-Kling, if it’s transported on pallets that happen to get splashed by chlorinated water.
“Dump chlorinated water onto wood or cardboard, and boom, you have TCA,” said Henick-Kling. “You only need parts per trillion, tiny amounts,” for the chemical to be detectable.
In the Blended Learning program, enology students learn how to make and market their own wines over the course of a year, developing their product to commercial standards in partnership with Washington wineries. Blended Learning produces a small run.
“200 cases is a lot for us,” said Henick-Kling. Yet even in a limited run, “I save, because I don’t have to accept a failure rate of two to seven percent, or in some cases even higher.”
Inconsistency in natural corks would be a big problem in the small number of bottles the university produces for research, said Harbertson.
“We cannot simply discard several and look for one with a good closure,” he added. “Every bottle needs to reflect the quality of wine produced for a particular research project.”
Bigger wineries have made the same switch to caps for the same reason.
“If a consumer opens their wine, and it happens to be corky and they don’t like it, they may not know it’s the cork. They blame the winery,” said Henick-Kling.
Breathe in, breathe out
Since wines started flowing into glass bottles in the 15th century, corks, made from the bark of the cork oak tree, have been the main stopper. Today, about 80 percent of the world’s 20 billion bottles produced annually are sealed with cork.
Cork is spongy enough to be forced into the neck of a wine bottle, but expands to form a seal. Cork quality can vary, however, and wines can breathe or age differently depending on cork variability.
“A perfect cork doesn’t let in air,” said Henick-Kling. A bad cork will quickly oxidize wine. The problem, he said, is there is no practical way to test every cork, so winemakers always run a risk of a corky or poorly aged wine.
Under caps, “you can control oxidation. You can completely keep it out, or allow a small, controlled amount of oxygen to get in,” Henick-Kling added. Airflow through a cap is controlled by the kind of plastic liner that forms the seal. Some liners breathe, others don’t. “With a screw cap, I don’t have to worry. It’ll be fine for 20 years or longer.”
Pros and cons
Researchers are studying how wine – and consumers – react to different closures.
“There is interest in the industry to see how these wines change,” said WSU food scientist Carolyn Ross. A 2007 study by scientists with the Australian Wine Research Institute looked at changes in wine properties during two years of storage under cork and caps.
“The chemical reactions that occur in the wine vary with the closure, due to the different amount of oxygen that is present,” she said. Under caps, Australian researchers found in some wines reduced aromas — unwanted sulfur compounds smelling subtly of rubber, mocha or struck flint. Reduced aromas can also develop under corks. It takes time for these aromas to develop.
“A lot of people drink their wine before they see change,” Ross said.
A 2007 study at Oregon State University looked at how different closures affect consumers’ purchase intent and price expectation. The study found consumers are willing to pay less for caps. Ross suspects the situation may have changed since then.
“People are understanding it more,” she said. “They’re exposed to more screwcaps now, on higher quality wines. People who are really experienced with wines may have already worked through that.”
Aesthetically, caps and corks are different. Screw caps twist off. It requires some finesse with a corkscrew to open, but the satisfying pop when the cork comes free is a traditional sound of celebration.
“There’s a certain, satisfying sound, and a certain feel, when you’re removing the cork,” said Harbertson. “I would miss that.
“But I don’t want the hassle of cork taint,” he added. “Most of us would prefer not to deal with it.”
– Seth Truscott
Winemakers converge for wine trial showcase, learning and networking
Ninety-four winemakers gathered for the second annual Harvest Trial Showcase held on March 18 at WSU Tri-Cities in Richland. The Washington Wine Technical Group and Washington State University Viticulture and Enology Program partnered to host the seminar and wine trial tasting.
The two groups started the event to bridge academic research and practical winemaking in a meeting of the minds where free dialogue takes place. Young winemakers learn the importance of solid experimental design, while seasoned veterans contribute practical experience, glean the latest in research and hear about their peers’ recent projects.
The Trial Showcase featured a vintage review by Josh Maloney, director of winemaking at Wahluke Wine Company, comparing their 2013 and 2014 vintages.
Thomas Henick-Kling, WSU Viticulture and Enology Program director, covered microbial issues that can occur during wine fermentation and their effects on wine quality. Some problems are compounded when less desirable winemaking conditions arise, such as high pH, compromised fruit or exposure to high levels of oxygen.
José Santos, president of Enartis Vinquiry, expanded on the microbiology theme by detailing practical preventative steps to achieve clean fermentations and sound wine storage. Remediation was covered for those cases when all else fails.
The latter part of the day was devoted solely to the presentation of harvest trials data and tasting the resulting wines. Four wineries presented their data and wines. The tasting was very Cabernet-Sauvignon-centric with choice offerings presented by Walla Walla Vintners, College Cellars, Long Shadows and 14 Hands. Matt Oakley, assistant winemaker for Long Shadows, presented interesting data on adding tartaric acid to wine to assist in cold stability. Tim Jones, Assistant Winemaker for 14 Hands, compared Pulsair (a proprietary system using compressed air) versus manual pump-overs for achieving skin extraction during red wine fermentations.
Part of the allure of the Trial Showcase is the ability to learn, socialize and taste great wines all at the same event. The day concluded with tours of the new state-of-the-art Wine Science Center at WSU Tri-Cities lead by WSU enologist Jim Harbertson, research winemaker Richard Larsen, and viticulture and enology director Thomas Henick-Kling.
Following the tours, the Washington Wine Technical Group provided drinks and appetizers at That Place Pub and Eatery to further facilitate industry networking.
– Richard Hood, President of the Washington Wine Technical Group
Save the date: Vintners in the Vineyard on Red Mountain June 6
Enjoy majestic vineyard views of Red Mountain, a delicious dinner and more Washington wine selections than you can taste in one evening: all for just $95!
Join 25 exceptional winemakers for Vintners in the Vineyard, 6 to 9 p.m. Saturday, June 6, at Col Solare Winery, 50207 Antonori Road, Benton City.
Each participating winery will be pouring three to five of their latest releases, making this an excellent chance to choose from more than 100 wines and see what’s new with Washington wine. Washington State University viticulture and enology students will be pouring their Blended Learning wines.
Gourmet food will be catered by Jake Crenshaw of Olive Marketplace & Cafe in Walla Walla.
Tickets are available through the Auction of Washington Wines.
– Erika Holmes
Washington state vintner shares expertise in new video
Is decanting necessary? Why shouldn’t you fill a wine glass more than halfway? How do you examine the cork? How do you choose a wine at the grocery store?
Patrick Merry, owner of Merry Cellars Winery, answers these questions and offers tips for pairing food and wine in a recent video created by WSU Global Connections, part of WSU Global Campus. This video packs hours of wine education into 40 minutes, and is now available on YouTube.
For a list of upcoming Global Connections events, please visit connections.wsu.edu.
Highlighting WSU V&E student and faculty achievements
Viticulture and enology undergraduate student Kaelin Campbell was awarded a $1,000 scholarship for the 2015 fall semester. The V&E Program won the $1,000 scholarship funding for raising the most money from items donated to the WSU College of Agricultural, Human, and Natural Resource Sciences Honors Silent Auction held March 26.
Soil scientist Joan Davenport was elected to the 52nd Annual Class of Fellows of the American Society for Horticultural Science and will be honored August 4, 2015, during the ASHS Conference in New Orleans.
Viticulturist Markus Keller was appointed science editor for the globally recognized American Journal of Enology and Viticulture by the American Society for Enology and Viticulture Board of Directors. His tenure will begin in 2016.