Dew the Twist

November 1st, 2023

Dew the Twist

On more than one occasion I’ve gone to recommend a wine of quality, and found resistance because the wine was sealed into the bottle with a (gasp!) screw cap. Now, to be fair, I understand why one might be resistant to a bottle of wine enclosed with the same technology used for a 2L of Mountain Dew, but fortuitously for us though, it isn’t the same technology, it is in fact much better than the cap to a bottle of the Dew.

Screw caps, also referred to as Stelvin enclosures, were developed around 1960 in France and put into use shortly thereafter, though they would face opposition, mostly aesthetic, for years to come. The traditional use of cork likely stems back to the 6th century B.C.E with cork being used to seal amphorae or barrels of wine. Of course this means that tradition, pomp, and circumstance had plenty of time to develop around the mystique of the opening and presentation of wine. Look up “port tongs” on YouTube sometime, it’s a hell of a way to open a bottle of wine.

These days, the majority of cork production in the world comes from cork oak trees (Quercus suber) in Portugal, the bark of which can be peeled off every 9 to 12 years without killing the tree. Based on geography, it isn’t hard to imagine who Portugal’s top cork customers have historically been: Spain, France, Italy, Germany, etc. Rumor has it that those further afield, New World, cork customers may not have always gotten the primo goods.

In the 1960s and ‘70s, winemakers in Australia and New Zealand noticed that they seemed to have a higher than average rate of cork taint, or TCA. With the advent of the screw cap enclosure Australian wineries led by Yalumba began experimenting in earnest in 1973, improving the technology along the way. Without getting too nitty gritty, the results were promising.

What has been found over time is that the Stelvin enclosure has a lower rate of cork taint and oxidation, as well as less bottle variation. A conversation that I had with Murray Barlow, of South Africa’s Rustenberg winery, a number of years ago really drove that point home (though forgive me if I’m a little fuzzy on the details, it was quite a long time ago).

He told me that the winery had made an experimental lot of wines from the same grapes in a single vineyard, but half the wine was put under cork, and half the wine was put under screw cap. After a period of time, 7 or 10 years I believe, they started opening bottles to see how they had aged. What they found was that there was much more uniformity in the wines bottled under Stelvin, whereas the wines bottled under cork showed a lot more variability and in general seemed to have aged more rapidly. After this experiment they began putting almost all of their wine under screw cap, aside from the high end reds in the American market. He said American consumers liked the tradition of pulling a cork. Pop!

It isn’t all sunshine and roses though, there are some issues with Stelvin. Much like corks, not all screw caps are created equal, the liners can have different quality levels and offer different oxygen transfer rates which will affect how a wine ages. A good rule of thumb would be that if the wine is $7, then it probably isn’t worth trying to age it for very long. No longer than the drive home at least. Additionally, since the screw caps allow less oxygen in than cork does, reductive wine, the opposite of oxidation, is a more common problem. But at least this problem can be ameliorated with more time bottle aging, or exposure to oxygen. Nothing can be done to help an oxidized wine.

So next time that you’re out shopping, fear not wines with a twist top, but you can still be wary of the Mountain Dew.

-Joe Buchter, Import Wine Buyer

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