Vino Lok: The Cork Alternative
Cork has been in use since ancient times when the Egyptians and Greeks discovered its fantastic properties for a myriad of uses. It was first used as a wine closure in the 1600's by the famous Dom Pérignon, and then migrated from there around the world and has been the predominant wine closure ever since.
Basically, even though it is a superior closure to oil soaked hemp and wood for the ancient times, there are many inherent problems with it. These problems focus around the bastardly cork taint, the chief cause of which is the presence of 2,4,6-trichloroanisole (TCA) in the wine. Corked wine containing TCA has a characteristic odor, variously described as resembling a moldy newspaper, wet dog, or damp basement. In almost all cases of corked wine the wine's native aromas are reduced significantly, and a very tainted wine is completely undrinkable (though harmless).
While the human threshold for detecting TCA is measured in the single-digit parts per trillion, this can vary by several orders of magnitude depending on an individual's sensitivity. Detection is also complicated by the olfactory system's particularly quick habituation to TCA, making the smell less obvious on each subsequent sniff.
The production of TCA in wine is complex, but mostly results when naturally-occurring airborne fungi are presented with chlorophenol compounds, which they then convert into chloroanisole. Chlorphenols taken up by cork trees are an industrial pollutant found in many pesticides and wood preservatives. Chlorphenols can also be a product of the chlorine bleaching process ironically used to sterilize corks.
The incidence of bottles with cork taint is estimated to be between 1 and 15 percent. The former figure is from the cork-industry group, APCOR, which cites a study showing a 0.7-1.2% taint rate. Anecdotal evidence from wine professionals suggests that the rate may be substantially higher. In a 2005 study of 2800 bottles tasted at the Wine Spectator blind-tasting facilities in Napa, California, 7% of the bottles were found to be tainted.
As a young winemaker coming up in the industry, I was distressed by all the problems associated with cork closures, and with no particular loyalty to the closure outside of its' history and tradition, I opted to go cork free from day one.
The options for cork alternatives are many, but I never really liked pulling synthetic closures and decided to go with Screwcaps, which eliminate the problems of TCA contamination, given that the winery is free from it, which we are.
Starting in 2006, we also began using a new glass closure called the Vino Lok, becoming the first Washington winery to bottle with this closure. We were encouraged by its use in Austria and by Peter Rossbeck of Sineann. Closure wise, it is identical to the properties of Screwcap, but more elegant and presentable at the table. We have been extremely pleased with the Vino Lok and will continue to bottle using only glass and screwcap.