A toast to aluminium screwcaps

Aluminium screwcaps

Blog post

There are few disappointments greater than opening a fine bottle of wine just to find that it tastes like a musty basement. For centuries, this risk was practically unavoidable. Corks were the principal way that wine bottles were sealed (prior to that, the French used oil-soaked rags!), and the possibility of cork taint was always lurking.

But all that changed with the arrival of the aluminium screwcap.

Enter the screwcap 

The revolution started in 1964, when Peter Wall, a winemaker at Australia’s prestigious Yalumba winery, contacted Le Bouchage Mécanique (LBM), a French company in the heart of Burgundy. He knew that LBM had been experimenting with alternative sealing systems for bottled wines, and he was searching for a solution to the frustrating cork taint problem. LBM, which is now part of the Amcor Group, responded by developing the “Stelvin®” screwcap, which combined an aluminium cap, a plastic liner, and a long metal skirt that imitated the traditional foil.

The Stelvin® was trialed by Swiss winemakers for their white Chasselas, a wine particularly vulnerable to cork taint. It proved to work, and Austrian and German winemakers soon took note, adopting aluminium screwcaps for their white wines in the 1980s.

Sealing the deal down under

But screwcaps still had a serious image problem, despite their many advantages. Wine drinkers considered them cheap-looking, better suited for jug wines than vintage Burgundies.

And then, in 2000, 13 winemakers from the Clare Valley in Australia grouped together to release their premium Rieslings under screwcap. The following year, the Australian Wine Research Institute published an earthshaking report, after sealing a Clare Valley Semillon wine with 14 different closures, including natural cork, technical cork, plastic corks, and screwcaps. Their findings? The screwcaps performed best in practically every regard.

Meanwhile, in New Zealand, a collection of nearly 30 wineries created the New Zealand Screwcap Wine Seal Initiative in 2001, after deciding that too much of their wine had been ruined by cork contamination.

Aluminium screwcaps are now the undisputed closure of choice in Australia and New Zealand, reaching more than 90 percent of the two wine markets.

Taste you can count on…

Arnaud Riess, Director Sales and Marketing, Specialties, is based in Constellium’s plant in Singen, Germany, the global leader for aluminium closure sheets. He says there is a clear advantage for wine producers, retailers, and customers to switch to screwcaps: “Neutral in taste and smell, non-toxic, and resistant to corrosion, screwcaps guarantee consistency and uniformity—you can be sure that every bottle in a given vintage will taste exactly the same.” Some screwcaps now come with a selection of liners that precisely control the oxygen transfer rate and how a wine will age. And because screwcaps minimize interaction with oxygen, winemakers can significantly reduce the amount of sulfur dioxide they use.

Natural corks, on the other hand, are all different, and provide variable results. Random oxidation and premature maturation are two potential problems. Worst of all is TCA, or 2,4,6-trichloroanisole, also known as cork taint—a compound that can arise during the cleaning process, when yeast interacts with chlorine. An affected cork will give a wine a moldy (or “corked”) smell and taste. TCA affects anywhere from 3-7% of wines bottled with cork.

It still remains to be seen how aluminium screwcaps affect the taste of a premium wine that is aged for several decades. But most wines are meant to be drunk within a few years of bottling—and for that, screwcaps have proven their worth.

…and many more reasons to switch

Anyone who has ever struggled with a bottle opener can appreciate the convenience of aluminium screwtops (and any restaurant waiter on a busy night has good reason to love them, too). They are safe and easy to open and close, requiring nothing more than a twist of the wrist. Plastic corks, on the other hand, can be extremely difficult to remove, and are practically impossible to put back into an unfinished bottle. And while a natural cork can crumble into the bottle, that will never happen with aluminium screwcaps. 

Arnaud Riess also sees design and cost advantages: “A screwcap can add to a bottle’s visual appeal, just like a label. Technology offers unlimited possibilities for one-of-a-kind closures with a range of designs and finishes.” Then there is the cost benefit—aluminium closures can be produced in large quantities, for an excellent price-performance ratio.

The genie is out of the bottle

As the stigma fades, nearly one-third of the world’s bottled still wines—or billions of bottles a year—are now sealed with aluminium screwcaps.

Studies have found that millennials, who are less wedded to tradition, tend to prefer screwcaps to cork, even in conservative wine markets such as France and Germany. Rosé wines, a favorite of younger generations, have been on the rise, and are bottled in a range of different shapes, often with screwcaps.

Even premium winemakers such as PlumpJack Estate in Napa Valley have come around, and it is no longer surprising to see screwcaps on vintages at every price. While the contents might be red or white, and the provenance down below, up above, or somewhere in-between, winemakers around the world have made it clear that aluminium screwcaps are here to stay. Cheers!

*Constellium does not advocate the abuse of alcoholic beverages. Please drink responsibly.