Local Wine Co's Blog


Where did the “screw cap” come from? by cdbakunas
October 19, 2010, 11:23 am
Filed under: Libations | Tags: , , , , ,

Where oh where did the screw cap come from, and where oh where will it go?

The classic cork closure, developed for bottling wine circa 1600 has remained a very static technology. Harvest a thin layer of bark from cork trees in Portugal and Spain, sanitize the bark and cut to specific diameter to match the neck of a wine bottle. Voila, you’ve sealed your bottle of wine which can then be transported or stored for aging. Where did cork technology come from? Its predecesor was a small piece of hemp cloth soaked in olive oil that was jammed into the necker with a blunt piece of wood. This transition to cork closures was greatly aided by the ingenious monks from Dom Perignon who realized that cork was better than grimmy pieces of oil soaked rags. By 1795 the first patent for wine corks was issued in England which closely coincided with glass production which became more efficient and standardized. As early as 1750 Spain had its first cork production facility to supply the thirsty wine drinkers of Europe an improved closure.  So why hasn’t this technology changed over the last 400 hundred years? 90% of the world’s wines were still under cork as late as 2002. Yes, the screw cap, or the twist cap, is growing in popularity and acceptance but has not been entirely embraced

In the 20th century screw caps pop up under the eponymous name Stelvin. Stelvin technology was created in the 1960’s by La Bouchage Mecanique, a French company that was subsequently sold in the late 1960’s landing in the hands of Australian Amcor, a multi-national packaging company headquarted in Melbourne.  But is this really where the screw cap came from. Whiskey producers might have something to say about the evolution of closures.

In 1856 a thin cork disk attached to a metal screw cap is introduced in whiskey production. Hmmm, sounds like cork served again as a proper barrier to liquid beverages and was the precursor to the wad of plastic, mostly commonly made from PVDC. PVDC is attached to the underneath side (or wad) of modern twist caps (polyvinylidene chloride or Saran resin. Sound familiar? You got it, it’s Saran Wrap!). The first patent on twist cap technology was in 1858 by John Landis Mason (yup, the Mason jar) with a zinc twist cap. Further enhancements were made to the screw cap and its application was brought to wine bottles by a gentleman name Dan Rynalds in 1889. Mr. Rynalds invented the wine screw cap in England but the technology never caught on. There seemed to remain a pesky problem with wine’s acid corrosive relationship to metal. It wasn’t until Le Bouchage Mechanique invented an aluminum twist cap, in the 1960’s, that had a chemically treated wad facing that worked harmoniously with wine’s low pH levels (high level of corrosive acid).

So why are we still emotionally connected to cork? And is there truth in the belief that corks allows wine to breath over time, thus enhancing its character as it ages.  The real deal is that when bottling under cork there is a margin of oxygen to the order of a few tenths of a milliliter of air that is diffused into the wine in the first few weeks. And a few hundreths of milliliters over the next four months. This is significant as oxygen plays a critical role in wine making and the aging of wine.  Stelvin, or screw cap, closures reduce this diffusion to nearly nil. This then poses certain bottling problems under Stelvin and running the risk of creating a reductive environment inside your bottle.  Reduction can raise its head in a finished bottle of wine smelling like rotten eggs (hydrogen sulfide) to burnt match or burnt rubber (thiols or mercaptans from oxidized hydrogen sulfide) all the way to vegetal, rubbery, onion like aromas (disulfides).  As further studies continue on the reductive potential of screw caps gains are being made in order to eliminate these off putting aromas.

Simply knowing that screw caps are much more effective in reducing cork taint and spoilage caused by TCA (trichloroanisole), an occurrence as common as 5-6% failure rate, is reason enough to search for alternative closures. Will cork remain with us for more generations to come? Or will a new technology usurp screw caps and capture the emotional attention of wine drinkers around the world? I just don’t know, but am excited to watch how this story unfolds. Let us now raise a glass in the hopes of never having a corked or reduced bottle of wine again.


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2 Comments so far
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This is a great article. I find this subject really interesting, particularly because it is one about which so many wine-drinkers are fiercely impassioned.
Why is it that we are still emotionally connected to cork? I think for many it may be simply attributed to its ceremonial quality. The extracting of the cork has become, for many, as integral a part of the wine-drinking experience as the wine itself.

One day practicality and finance will succeed in dictating the use of alternate closures; and who knows, maybe the romance formerly ascribed to the extracting of a cork will someday be redirected to the twisting off of a cap.

I raise my glass to that.

Cheers,

Paul Kalemkiarian,
President, Wine of the Month Club

Comment by Paul Kalemkiarian

I’ll raise my glass to that. Thanks Paul

Comment by cdbakunas




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