Supreme Cork Justice

Umbra on wine bottle stoppers 8

Dear Umbra,

Here's a question I couldn't find an answer to in the Grist archives: What kind of plastic is being used for the corks in wine bottles? If I decide to put a bottle in the cellar for several years, will the plastic leach into the wine? Thanks for your help!

Holli B.
Portland, Ore.

Dearest Holli,

No need to fret: Wine bottles plugged by plastic stoppers or screw-tops can be stored upright, with the plastic separated from the liquid, getting you around the potential problem of plastics leaching into the wine. Natural cork must be kept moist so it won't degrade and allow too much oxygen to enter the bottle; thus, corked wines are stored on their sides with the wine lapping up against the cork. For plastic stoppers, or "synthetic closures," this leisurely recline is unnecessary.

Your wine doesn't need to recline.

Synthetic wine bottle plugs are made from oil-based thermoplastic polymers (aka stretchy, rubbery, but also plasticized chains of molecules). Beyond that, who knows -- I think it's a trade secret. Supreme Corq is one major manufacturer of solid stoppers, which are made from a thermoplastic elastomer; the "corks" are certified by the Food and Drug Administration and approved for organic use. Nomacorc, which uses foam in its stoppers, launched a carbon footprint study to see which closures were best for climate friendliness, and its products placed second -- after natural cork. (In the "no surprises here" category, aluminum screw caps came in last.) As to quality impacts, there are some reports that synthetic stoppers can cause oxidation problems that age vino prematurely. Those are a few eco-ish tidbits of the "for what it's worth" sort, but I could find no reports of leaching. I'm somewhat reassured by the knowledge that the wine industry is obsessed with flavor, quality, and product control. If the synthetic stoppers were adding something unwanted, wouldn't we at least hear a whisper about it from oenophiles? That thought is a small comfort in the absence of information, but it's perhaps worth drinking to.

Although a nice glass of wine can play an important role in our environmental activism (see: staying positive), the environmental impact of the bottle closure has less to do with leaching plastics and more to do with overall manufacturing footprints. Naturally corked wine is a little prone to "cork taint," a musty, cardboard-y taste caused by compounds in some cork. The taint issue is the only problem with natural cork, which is an environmentally preferred product. Cork oak forests in the Mediterranean are sustainably managed for the health of the trees and income of surrounding communities. A cork oak tree -- which can live for about 200 years -- has thick bark that is harvested every decade or so, and then grows back. The corks themselves are organic material and hence biodegradable. None of this can be said of plastic.

In short, plastic stoppers may not harm our health, insofar as we currently know -- but cork is the real corker where planet health is concerned. As to whether the long-term storage of synthetically plugged wine is recommended by connoisseurs, I know not. There are plenty of wine experts out there to answer that question, so I leave it to them. Happy sipping.

Rieslingly,
Umbra

 

Yours is to wonder why, hers is to answer (or try). Send your green-living questions to Umbra.

Umbra Fisk is Grist Research Associate II, Hardcover and Periodicals Unit, floors 2B-4B.

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  1. Maeve Posted 3:32 am
    17 Sep 2008

    Corked wineWhile I'm no expert (learning slowly, but surely), I believe "corked wine" generally refers to bad/ruined wine caused by TCA contamination (from http://www.cellarnotes.com, the first google site that came up "A 'Corked' wine is a wine that has been bottled with a cork that is contaminated with TCA (2,4,6-Trichloroanisole). TCA contamination usually comes from corks but can also come from barrels, other cooperage or even, apparently, from wood within the cellar including walls or beams. The term 'corked wine' is applied to all wines with TCA contamination because corks are the souce of most of the problems."
    So, your reference to wine sealed by natural cork as "corked wine" might give some the wrong impression (easily fixed by actually -reading- the article, but still).  
    Just wanted to comment and give you a head's up. :)

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  2. murphy97219 Posted 6:19 am
    17 Sep 2008

    plastic corksUmbra~ Holli from Portland might have a cellar, in which bottles are racked on their side for storage. Sure she can stand them, but maybe her storage unit is racks, not shelves or counter top.
    Holli~ With that in mind try to stand the bottles as the acid will certainly dissolve something of the plastic. Remember, in PDX metal screw caps can be recycled after to pop the plastic insides out.

    As can beer and soda bottle caps.

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  3. DrMetzler Posted 7:31 am
    17 Sep 2008

    WIne CorksHello, I am a wine person and I can tell you that the debate about corks is heated in the "wine world" Wine Spectator has written articles about it, as have I, and if you are going to age a wine for any amount of time you need natural cork, however that being said, they are working on a screw cap that will allow for air exchange which is what natural cork does. Plastic does not allow for this but wines that have these types of closures usually do not need aging. There are many wines out there now with screw caps thgat are terrific! Caymus Conundrum comes to mind, that is a white blend and they won't tell you the grapes used.Its fun to try and guess! As for leaching I will tell you that I do not want my wine sitting on plastic, definitely store these upright and remember thay will not really "age". In other words don't buy a cabernet sauvingnon with a rubber cork because that does need aging.Hope this helps!

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  4. ballestrem Posted 7:34 am
    17 Sep 2008

    plastic corksThe problem is that winemakers don't indicate on their labels whether they have sealed the bottle with cork or plastic.  Screw tops are easy enough to identify, but usually the bottle tops are covered with a dark material (plastic, metal, etc) so it is hard to tell with those.  Do you just remove that covering to answer the lay down/stand up question?  I suppose that would work, so long as that doesn't somehow compromise the cork-sealed bottles.  Hmmmm ...
    Murphy - yes, I do have a lovely, hand-made wine rack that only allows the bottles to be stored on their sides.  But it's good local wine - there's always room on the floor in the basement if they must stand up  :-)

    -Holli

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  5. rivergal Posted 9:17 am
    17 Sep 2008

    Lose the cork and heavy glass and go box wine!We live in AK which produces very little of its own wine, so all the wine we drink has to be shipped up from the Lower 48 (Seattle is 1500 miles away).  The energy used to transport glass bottles is substantial, and there's not always a local market for recycled glass here.  So, we've increasingly found ourselves buying decent box wine.  Some plastic is used to make the inner bladder and spigot but probably about the same amount as would be used in four bottles, the equivalent of the 3 liter bladder's capacity.  The box itself is recyclable cardboard.  You can get drinkable table wine if you go up a level from the older box brands, e.g. a 3 l box for the equivalent of $6/bottle ($24).  There's better variety and quality in reds than whites but as box wine's popularity increases that will change.  The best part is ease of storage -- the box fits better in the fridge than bottles do (especially 1.5 l bottles) and there is little air exposure after the bladder is tapped, so you can enjoy the wine over several days or weeks with no change in quality.  If you're going to drink vin ordinaire, do the environmentally conscious thing and help increase the market for boxed wine!  Thanks!!

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  6. BMendenhall Posted 3:25 pm
    17 Sep 2008

    So many reasons to choose corkThe best environmental choice is wine that is sealed with natural cork.  And that may go for Alaska also.  For many in the lower 48, wine is shipped from far away, as well.
    The cork oak forests of Spain and Portugal are privately owned and extraordinarily diverse natural habitat for several endangered species. Without the income from wine cork sales, the owners of these ancient sustainably harvested forests will likely be forced to sell their land for development.  Other uses of cork that have developed more recently do not provide sufficient quantity of usage to make up the loss of wine sealing corks.
    Audubon Magazine had a really good article in January 2007 (http://www.audubonmagazine.org/features0701/habitat.html) that will give you the detail on this.  The article also describes the steps that the wine cork industry has taken to almost completely prevent TCA contamination in good quality corks.  
    The way you find out how a wine was sealed is to ask the salespeople where you are shopping - and tell them that you only buy wine with natural cork because it is the best environmental choice and protects important natural habitat.  

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  7. Bearclaw Posted 2:34 am
    18 Sep 2008

    AwfulThis is awful people sitting around worrying around wine corks.

    My goodness the world has gone insane !!

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  8. grist4themill Posted 4:46 am
    22 Sep 2008

    ChampagneI took a tour of the Moet & Chandon cellars in Epernay, France this summer.  They said plastic corks are now being used on some batches of champagne during certain phases of the extensive process, and that any natural corks used during processing are recycled.  Of course the final product uses natural cork.  They cited the rising cost of cork as the reason for the shift to include plastic, and I got the impression this rising cost is caused by a shortage of natural cork.  Your article suggests the cork oak forests remain healthily in tact and able to sustain global demand.  Perhaps, rising cork prices reflect the higher and higher costs of shipping?

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