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Carlos Macku, Ph.D.,
Kyle Reed, Ph.D.,
Department of Technical Services,
Cork Supply, Benicia, CA
ntil the early 1980s, natural
cork was basically the only
material used by the wine
industry to close a bottle
of wine. Cork was the only choice
because it was considered the perfect
material, unchallenged by centuries
of winemaking practice. Then in 1981
and 1982, Swiss scientist Hans Tanner
and his team published research
that made the landmark association
between 2,4,6-trichloroanisole (TCA)
and cork taint.1,2
Winemakers have always been well
aware of cork taint, but the problem
was considered a very minor annoyance
due to its very low rate of incidence.
However, anecdotal accounts
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have reported that, since the end of
World War II, the rate of taint climbed
close to double-digit figures, particularly
during the 1970s and 1980s.
This situation, understandably, created
much angst among winemakers,
while at the same time leading to an
epic struggle to find a satisfactory
means of wine packaging. During the
ensuing years, innovative and entrepreneurial
individuals worked hard to
develop reliable and consistent wine
closures that kept precious wine vintages
away from oxygen with no negative
effects.
At the same time, commercial globalization
and the renaissance of scientific
winemaking have added product
convenience and quality consistency
to the potential benefits of new and
daring closure alternatives to natural
cork.
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Today, producers and consumers
can choose from many types of wine
closures. Wine packaging (probably
one of the most challenging of all food
barriers) has certainly evolved from
the days when the product was transported,
stored, and sold in Egyptian
amphorae or medieval wooden barrels.3
For the last ten years, three types of
wine closures have clearly dominated
the market: natural corks, synthetics,
and screw caps or screw tops (also
known as Roll On Tamper Evident or
ROTE). Other types of closures are also
available, such as Vino-Seal, and Zork.
Nevertheless, this article will focus on
the first three types of closures and
establish useful comparisons between
the three systems.
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FIGURE 3: Oxygen Transmission Rates for the most widely-used wine closures (based on air measurements).
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