They are safe - and they aren't safe. Lead capsules are coated with a thin layer of tin for handling reasons. The tin is "slicker" and it acts as a lubricant as the sheets of lead pass through various cutting and stamping machinery. Pure lead would "grab" moving parts and destroy its own shape in the process.
The tin coating is fortunate for health, but it is not the only safeguard. Most capsules are also painted, at least on the outside, and this forms another barrier to the toxicity of lead. (Tin is a comparatively safe metal to ingest.)
Normal use of tin-coated lead capsules as covers for wine closures has been considered safe for many decades. If the consumer cuts the capsule well below the lip of the bottle, then wipes the top of the bottle before removing the cork, he will get essentially zero lead in the wine as it is poured from the bottle. This assumes there was no corrosion under the capsule, which is usually true for most white wines.
The problem is that wines which have been aged in the bottle usually have corrosion under their capsules. The corrosion is seen as a white, grey, black or brown, pasty, granular sludge under the capsule top and on the outside top of the cork. Some of this sludge is bound to be lead carbonate, oxides, acetate or tartrate.
I've seen waiters skip the capsule cutting ritual and just screw the corkscrew into the cork right through the capsule! When the cork is pulled, it comes out through a jagged hole in the capsule. Pouring wine through this hole in the capsule is a sure way to get foreign material from under the capsule into your wine glass.
Hopefully, nobody eats where I don't either anymore, and this kind of thing doesn't happen now. If the waiter doesn't wash, or at least wipe, the bottle top after removing the capsule top, the lead from sludge will end up in somebody's glass (and later, in his liver). Improper storage can make it far worse: Imagine a bottle of great red wine lying on its side in a location which allows a wide rise and fall of temperature. When the temperature rises, wine in the bottle expands and (if the cork seal isn't perfect) a bit of wine can seep out between the cork and the bottle neck. It contacts the underside of the capsule even though no obvious leak can be seen. When the temperature falls again, the wine inside the bottle contracts - drawing the "seepage" wine back into the bottle by the original route past the cork. After several cycles of this you can imagine wine corroding the underside of the capsule, dissolving lead and pulling it into the bottle. The chance of lead pickup by this mechanism depends upon how poorly the cork seals, how much the temperature varies and how long the storage lasts.
That tends to make old red wines more unsafe than young white wines. But using care and common sense can keep the intake of lead from old corroded capsules to near zero levels.
None of the story so far was a reason to ban lead. The lead ban sprang from the industry's success at selling wine. Millions of wine bottles now lie buried in land fills around the world. Any lead capsules there are slowly decomposing so that the lead could eventually leach into ground water supplies. To stop this, legislation banning the use of heavy metals (especially lead) in packaging was first introduced in Connecticut, Iowa, Maine, New Hampshire, New York and Vermont. Other states have followed and there is now a similar federal bill as well. Lead capsules are a poor investment right now.
What can you do? You should follow the Wine Institute's mid-1990 recommendation and stop using lead capsules as soon as practicable. Obviously there will be a use-up period for existing inventories, but you should try to replace your lead capsules by the end of 1991 if possible. Some states, including California, will continue allowing the use of lead capsules by wineries beyond 1991 provided the capsules themselves were produced prior to the end of 1991. Each state has its own rules and it would only confuse to list them all here.
The best substitute for lead (except for the higher cost) is to use pure tin capsules. Using tin capusles will at least double your present cost for lead. The capsule makers are scrambling to find a cheaper look-alike for lead, and this search incorporates various plastics and aluminum-plastic laminates. Most of them don't look as well as lead on the bottle, but hopefully somebody will come up with a good one soon.
One thing bothers me about the way we talk about lead: Suppliers call them "tin-lead capsules" because of the tin coating. Common sense says that this may taint the word "tin" in consumers' minds and make them wary of using the perfectly safe pure tin. Wouldn't it be smarter to call lead capsules "lead capsules" (even though they have a thin tin coating)? Then when wineries change over to pure tin, the consumer will see the definite difference and not mentally condemn tin by its former association with lead.
Maybe tin's cost will make the problem go away when a supplier comes up with something cheaper and just as good. Don't plan on it in the next few months. Common sense says: Get your plans finalized now. Decide from today's choices and place your orders - at least for your 1992 needs. Suppliers may not be able to fill all the last minute orders that such a universal changeover will spawn.
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|Title Annotation:||ban on lead capsule use in bottling wine|
|Author:||Peterson, Richard G.|
|Publication:||Wines & Vines|
|Date:||Jul 1, 1991|
|Previous Article:||Westin continues its wine program.|
|Next Article:||Wine Institute's new regime; ASEV honors Leo Berti.|