Why we love numbers

We love opinions. Without them, what would wine writers write about? But we love facts even more, and the 100% Cork campaign is dedicated to disseminating factual information about wine stoppers because the facts support cork.

From consumer and trade opinion research on preferences and perceptions, to empirical market and sales data, to chemical and sensory analysis of faults and taints, to scientific research on oxygen transfer and sustainability – data continues to overwhelmingly confirm that cork is the leading choice for preserving wine, the best choice for the environment, and the preferred closure for both consumers and wine professionals.

46 %
in-store sales increase for wines identified as using natural cork
(source )
15 %
perceived quality increase in blind tastings for cork finished wines over screw caps
(source )


  1. Consumer and trade opinion research by respected independent research organizations such as Wine Opinions and Tragon (now Curion).
  2. Market data from Nielsen.
  3. Empirical surveys and data gathering.
  4. Blind taste tests.
  5. Environmental organizations such as the WWF and the Natural Resource Defense Council.
  6. Scientific research, testing and studies by not only the cork industry, but independent wine research organizations and laboratories such as AWRI and ETS.
112 grams

Amount of CO2 removed from the atmosphere and sequestered in every single natural cork stopper ( source )


number of cork trees cut down to harvest the bark and make cork stoppers


number of indigenous and endangered plant and animal species protected by native cork oak forests ( source )

Watch the Cork Facts video here

Using numbers to dispel myths

Large scale wine competitions with professional but anonymous judges show rejection rates of 1% or less for TCA contamination, against about the same 1% rate for wine faults such as oxidation and reduction. These numbers are backed up by chemical analysis and laboratory testing. So why do so many people in the wine world, both professionals and wine lovers, still cite higher numbers? For one reason, even educated tasters when sensing something is not right with a wine automatically say ‘it’s corked’, even though more often than not the reason is a different fault.


Reduction in TCA over the past 10 years for corks coming into the US ( source )


Rejection rate for cork taint for all submitted wines at the International Wine Challenge from 2007-2016 - vs. 1% for oxidation and .9% for sulfides (from the AWRI)


Identified cork taint in 3300 wines tasted by 70 judges at Indy Wine Competition 2008-2009

Key numbers that tell a story

While 70% of the world’s wines are sealed with cork, 88%* of the world’s best wines are sealed with cork.

That is why
97 %**
of wine lovers associate natural cork with quality wine.
More research on closures

*Wine Spectator's Top 100 List, **2017 Wine Opinions

That is why
97 %**
of wine lovers associate natural cork with quality wine.