India's First Wine, Food and Hospitality Website, INDIAN WINE ACADEMY, Specialists in Food & Wine Programmes. Food Importers in Ten Cities Across India. Publishers of delWine, India’s First Wine.
Skip Navigation Links
About Us
Indian Market
Wine & Health
Wine Events
Retail News
Contact Us
Skip Navigation Links
Wine Tourism
Book Review
Photo Gallery
Readers' Comments
Video Wall
Media Partners
Ask Wineguyindia
Wine & Food
Wine Guru
Gerry Dawes
Harvest Reports
Mumbai Reports
Advertise With Us
US Report on Indian Market Released
Top Ten Importers List 2015-16
On Facebook
On Twitter
Delhi Wine Club
UC Davis Study on Cork vs. Screwcap

Posted: Monday, 16 July 2012 16:37

UC Davis Study on Cork vs. Screwcap

July 16 : For many wine drinkers, the sight of screwcaps on a bottle indicates it is cheap wine but they have become increasingly popular with winemakers around the world including India, even as the opponents believe corks are a must for ageing wine but now University of California, Davis has been commissioned to conduct an independent 2- year Study to evaluate the closures.

 ‘Bottle Aging- Closure and Variability Study’ being conducted in partnership with the PlumpJack Group, a wine company that uses both screw caps and corks for its premium labels, aims to  compare the effectiveness of screw cap as compared with natural and synthetic cork as the wine closures.  Bottles of 2011 Cade Napa Valley Sauvignon Blanc, the Fumé styled barrel fermented wine from Cade Winery owned by the Group, has been chosen for the study.

Sustained amounts of oxygen may lead to degradation in taste and colour. Unlike corks, a screw cap doesn’t let oxygen into the bottle. It also ensures that a wine won't get corked (provided it was not corked during the processing because of unhygienic conditions in the cellar) – cork can be tainted by the chemical compound TCA (2,4,6-Tri Chloro Anisole) during its manufacture, leading to musty wine. Questions like whether a bottle of screw cap wine age as gracefully as a bottle with a cork or screw caps trap unpleasant hydrogen sulfide aromas that might otherwise be vented by porous corks, are being addressed in this independent two-year study. The goal is to provide direction for the industry so vintners can make informed decisions about which closures to use on their bottles.

"While natural corks have been used effectively for thousands of years, they are no longer a sustainable method of closure," said Andrew Waterhouse, professor of viticulture and enology at UC Davis, in a statement. "With this study, we hope to scientifically analyze the effectiveness of other closure methods and thereby to provide information and direction for the industry."

The two-year study will analyze wines under three different types of closures generally in use-screw caps, synthetic corks and natural corks- glass enclosures are apparently not a part of the study. The test group of 200 bottles of Cade Napa Valley Sauvignon Blanc 2011 will be monitored every few months using a spectrometer to detect changes in colour. The wines will also be chemically analyzed using oxygen sensors placed inside the bottles. The sensors allow the researchers to measure how a wine is aging without opening the bottle. The wines that show differences will be opened at the end of the study and tasted to determine if the quality has been compromised.

The study will determine the range of differences in each closure group, specifically, how much oxygen has been allowed into the bottles. When oxygen interacts with a wine it causes it to oxidize, changing its colour and taste. Corks and screw caps limit the amount of air the wine in the bottle is exposed to, preventing it from aging prematurely. "It's really a variability study," said Dr. Waterhouse. "We want to see how different they can be between themselves."

PlumpJack Group, which owns two wineries in Napa including Cade,  as well as two hotels, a wine shop and several restaurants, has been conducting in-house studies on the aging potential of screw caps since 1997 but decided to approach UC Davis, an independent body to assess the closures, making it an important study. It is not the first scientific study to be conducted on screw caps but it does employ new technology and is independent. Though many vintners find it hard to market screw caps to consumers, a company spokesman says the younger generation of wine drinkers is willing to embrace alternative closures.

Indian wine industry has seen a paradigm shift during the last 5 years or so with a strong move towards screwcaps and the market accepting them. The leading producer Sula has completely shifted to screwcaps barring their recent top-end variant Rasa (Retail Price Rs.1100 in Delhi) a barrique fermented Shiraz. Similarly, the UB owned Four Seasons uses cork only for the Reserve range- Barrique Reserve Cabernet Sauvignon and Barrique Reserve Shiraz (Retail Price around Rs.900). Grover Vineyards which had initially been reluctant to changes when Sula had pioneered, shifted to screwcaps and today only their La Reserve is in the cork. The common thread is the same in all the three top wineries-use screwcaps for young drinking wine and where aging potential is the key, they still owe allegiance to the cork.



Niladri Dhar Says:

Australian Wine Research Institute (AWRI) is at the forefront of research on wine closures and their studies are going on since the 90s. Anyone looking for in-depth and fascinating (quite technical though) results of their findings must visit their website and do a search...treasure trove of information. Their website - An example of the information you will find on the subject - (follow the links). Cheers, Niladri

Posted @ July 18, 2012 11:10


Want to Comment ?
Please enter your comments in the space provided below. If there is a problem, please write directly to Thank you.

Generate a new image

Type letters from the image:

Please note that it may take some time to get your comment published...Editor

Wine In India, Indian Wine, International Wine, Asian Wine Academy, Beer, Champagne, World Wine Academy, World Wine, World Wines, Retail, Hotel


Copyright©indianwineacademy, 2003-2020 |All Rights Reserved
Developed & Designed by Sadilak SoftNet