New Materials in Wine Sealing and Packaging
Flashback: March 1993
Dear Paul, I heard something not too long ago about lead getting into wine. Then I recently noticed that the 'foil" which covers the cork on a lot of wine bottles is different than what it used to be. Am I correct in assuming that there is some relationship between the two?
Yes, indeed, you are correct! According to The Wine Institute in San Francisco, in 1991 at least nine states (New York, Connecticut, Maine, Minnesota, New Hampshire, Iowa, Rhode Island, Vermont, and Wisconsin) have enacted laws which prohibit "heavy metals," such as mercury, cadmium, and lead, from being used in packaging materials.
This, of course, includes the "traditional" lead capsules (lead foil bottle closures) on wine bottles. These familiar closures are deftly removed by waiters with the little knife gadget on their "waiter's corkscrew," as a necessary preamble to extracting the cork. Capsules have been in use in the wine trade forever, it seems. And they have been made of lead for at least as long. But the new capsules are, of legal necessity, made from other materials.
Wineries must now use alternative closures decidedly free from poisonous heavy metals. Acceptable substitutes include closures consisting primarily of tin, aluminum, aluminum composite, plastic, and poly laminates. Many of these alternatives have already been in use in the industry for years.
The increase that you have noticed in the use of alternative closures is strictly an attempt to comply with the new legislation. Generally, legislation in the states involved affords a three-year transition period during which producers and manufacturers are to undergo a progressive reduction of heavy metals in packaging. So, you can expect to see increasingly more and more of these different foils.
There's another innovation that you may soon be noticing: synthetic corks! Traditional corks made from the bark of the cork oak suffer from two escalating problems: lower quality and higher prices! Generally, about 6% of corks available for use as wine stoppers are defective, although as much as 10% of the stocks available at any given time can be bad. Any wine that comes in contact with such a cork is liable to be adversely affected. The taste might go "off" or the wine might even get completely spoiled. (Same difference in my book!) Synthetic corks are inert and do not impart any flavor to the wine at all. Since they cost the same as "natural" cork the industry is looking at this alternative as a viable way to go.