Popping the Cork on the Screwcap Debate

Popping the Cork on the Screwcap Debate

Post by Chuck Hayward | August 7th, 2012

The debate over corks and wine is causing controversy once again, proving its unique ability to be an issue of contention for the foreseeable future. Much ballyhoo has been raised by the cork industry recently regarding Christian Canute, the owner of Rusden Winery in the Barossa Valley, and his decision  to forswear screwcaps in favor of corks (despite the fact that he only used screwcaps for one of the ten wines in his portfolio and even that was only for a few vintages).

Top: 1999 Clare Valley semillon, 28 months after bottling. Bottom: After 125 months

In other news, UC Davis and PlumpJack Winery recently announced the commencement of a two year study that will attempt to determine, once and for all, how different closures affect the ability of wines to age. (Read more about the study here). This research is taking place despite the fact that the Australian Wine and Research Institute (AWRI) has been involved in a similar project for more than a decade. That study, analyzing 14 different types of closures, is in the process of concluding that screwcaps are superior when compared to other types of seals. Looking at the picture above (courtesy of Old Bridge Cellars), I don’t think I would want any of the wines on the right side of the picture. And by the way, the screwcap bottles are on the left.

This is all great for science but it’s rare for consumers and those of us in the trade to experience first-hand proof that screwcaps are superior to corks for aging wine. Last year, JJ Buckley customers had a chance to determine how wines age under screwcaps at a unique tasting of pinot noirs from Mt. Difficulty  (read more about that event here), but there was no direct cork vs. screwcap showdown at that special event.

Same wine, different closures

So a festive JJ Buckley gathering a few weekends ago looked like a great opportunity to pull a few bottles from my cellar that would address the issue. Out came two bottles of 2002 Wolf Blass “Gold Label” Shiraz, one under cork and the other in screwcap, both stored at the same location since they were purchased. This was one of only five Australian wines exported to America where one vintage was sold in both screwcap and cork, so this provided us with a rare opportunity to taste the wines side by side.

The result: a hands-down preference for the bottle under screwcap. The bottle under cork had more diffused aromas, redolent of herbs and muddled spices and a more advanced palate lacking the signature message of deep shiraz fruit. With deeper aromas and flavors filling up the darker range of the fruit spectrum, the screwcapped bottle clearly left a fresher, more youthful impression with a core of soft fruits that had matured enough to show softer textures with just a hint of secondary complexity. It was as though the wines came from two different places.

While this is not a scientific study and merely another in a litany of anecdotal stories regarding the virtues of screwcaps, it’s also quite evident that our simple tasting will do little to settle this robust debate. Nevertheless, it sure caused a commotion among the JJ Buckley staff. Here’s hoping that everyone seeks out the opportunity to try the same wine under different closures, it’s truly an eye-opening experience.


  1. About six years ago, in the company of fellow Epic Wines Team Leaders, I recall tasting two bottles of Ata Rangi Martinborough Pinot Noir sent by the winery. One was in cork, the other under screw cap; same vintage, same bottling date. At the the time they were selling the wine in screw cap almost everywhere but the USA. The winery’s purpose was to give us a choice of either closure & they would comply with our decision.
    I vividly recall the greater depth & freshness of the wine under screwcap compared to the more earthy, darker flavors of the wine with cork closure. Both were great wines reflecting both their origin & the craft. We decided on the screwcap & have not looked back.
    The point here is that we’re making decisions on what flavor profiles we wish to buy & sell & our choices will determine the future flavors of wines. Its quite an interesting pivot point in the industry.

  2. I actually like non-fruity Bordeaux and Burgundies. I think for wines that need to age in the bottle, screw caps might not work all that well. Imagine it takes 100 years for a Chateau Margaux to reach it’s peak with a screw cap. What a time investment!

    1. Jonathan, the aging time depends on the OTR (Oxygen Transfer Rate) which can be controlled by design of the sealing liner in a screw cap. You can, in principle, age a Chateau Margaux even faster than it would with cork (If you felt this was desirable) by selecting a sealing liner with the appropriate OTR. Screw caps have the potential to perform far better than corks ever have. The technology is still being developed, so try to be patient.

  3. Two years ago I had a side-by-side comparison of Marquis-Phillips 2004 Sarah’s Blend with screw-cap and cork. The screw capped wine was notably superior to all four tasters.

  4. Is anyone going to speak of Sulphide Redux here? or how you can’t stack pallets of wines with screw cap because the caps are fairly easily compromised. I’ve tasted many many wines under various closures. I like screw caps with high acidic whites. I don’t care for it on ageable chardonnays, or reds with a lot of depth. They’re not the same. Everyone brings up that Plumpjack did it for a second on their nicest cab. I tasted it – it wasn’t horrid, but definitely did not compare to the finished in cork. Each closure has it’s pros and cons. Screw Cap is not for everything, but it doesn’t suck.

    1. Andrew,

      Experts (e.g., Tom Mansell with Palate Press) say that some closures allow lots of oxygen ingress (synthetic cork, bag in box, etc.) while some allow little oxygen (a good natural cork) and some barely any oxygen at all (screwcaps). It’s been speculated that a small amount of oxygen ingress can stabilize disulfides in the bottle, preventing them from breaking apart into the more potent mercaptan aroma compounds (which can smell like rotten eggs). This could explain why a “reductive” fault or flaw is often attributed to screwcapped wines, and the screwcap is given the blame. But, some Sulphide problems can be avoided with the wine making process.There is still considerable debate on this topic as screwcaps become more widely adopted around the world. But, screw caps are expected to eventually be the preferred closure because the oxygen transfer rate can be controlled by proper design of the sealing liner. There is no inherent property of screw caps that results in Sulphide problems with wine. Moreover, some would argue that screwcaps can help preserve volatile thiol aromas like passion fruit and grapefruit (an example is New Zealand Sauvignon Blanc, religiously bottled under screwcap).

      1. William,

        I have tasted many wines and on more than a few occassions a winery used a screw cap on a wine, and the wine had no fruit character to it.
        The problem was sulphide redux which dumbs down the fruit. I have read that this effects about 10% of wines with a screw cap closure. I am a fan of the closure myself but know that it is not right for everything.

        The problem with sulphide redux happening in a screw capped wine often has nothing to do with your example above – but I have heard the argument. It’s like when people say TCA is coming from an unclean winery – while it may be true at times, this is not the majority of the sulphide redux problem.

        The biggest problem with sulphide reduction is that the there is no fruit, unlike when a natural cork has TCA which is more easily noticeable – at least the consumer can point to a reason for the wine not tasting good (if they have the knowledge). Where as someone in this case can not point to an issue – the wine just doesn’t taste like anything special. Case in point I was at a trade tasting at Ft. Mason and a winemaker from good winery in Sonoma said ‘hey check out my petite sirah’ – I did, and it had no distinctive flavor to it. – Screw cap.

        While I realize you are the head of the screw cap program at Metacork – haha, and it looks like a great product! seriously, I had not heard of it and I am impressed. I still don’t think it’s the answer to everything. It might be a good idea for you to see that and be a bit more realistic. When you pay $50+ for a bottle you want to see a good, solid, and long natural cork. Some may be compromised by TCA but it continues to be the best for longevity. And synthetic corks works great and is much much more affordable than metacork – so it makes sense and the majority of major wine companies use it – including in Australia. Because it works. However, you have a great product there – I would love to learn more about it. The website seemed to be having problems or maybe that’s just my computer. Thanks.

      2. Andrew,

        The MetaCork Company, Gardner Technologies, Inc., was closed over five years ago, when it failed to raise the capital needed to go into full production with its only product–a result of its partner, Robert Mondavi Winery, terminating its agreement with GT, along with other house cleaning in preparation for its sale (to Constellation Brands). The MetaCork capsule was compatible with any cork, natural or otherwise. It simply provided an integrated means for convenient cork removal and bottle resealing. The MetaCork capsule was threaded and it screwed off and on the bottle. But it was not a screw cap that does away with corks. It was an enhancement of cork closures for consumers’ convenience.

        I point this out here just to make it clear that my comments about closures are not intended to support any particular product, but simply to spread the word that, regardless of shortcomings of past or present screw caps relating to the extent to which they prevent oxygen transfer from the environment into the bottle, the OTR (oxygen transfer rate) issue is about the sealing liner, not screw caps themselves, and liner technology is progressing as we speak (write). Research by wine-industry/academic-enology partnerships is leading to commercial startup efforts at producing liners that establish whatever OTR the winemaker specifies for each particular wine. As this technology matures, concerns of the sort you express (assuming you meant “redox” not “redux”) will likely pass, and I venture to say that we might find screw caps eventually becoming the preferred closure for all wines.

        It may be worth pointing out here that both Sulfur and Oxygen can have either beneficial or harmful effects on wine, depending on many conditions. The chemistry of wine is really quite complex.

        Finally, regarding your remark about the limitation on pallet stacking imposed by the possibility of aluminum-screw-cap deformation compromising the bottle seal, can you refer readers to your sources of data or other information on this issue? Thank you.

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