The environmental argument: corks vs. screwcaps

Interesting article:

http://www.wineindustryinsight.com/RSS/index.php/hop/latest/screw-cap-wine-blamed-for-loss-of-forest-in-new-campaign-to-revive-traditional-telegraphcouk/29276" onclick="window.open(this.href);return false;

ridiculous–this “argument” has been circulated for years. Evidently cork used for wine stoppers is only a tiny percentage of the cork used for various things–it’s an effort to play on emotions rather than reality claiming that screwcaps will destroy the environment. We covered this topic once on the other board.

alan

Alan,

Could not agree more.

Cheers!

Seems like a major spin, blaming screwcaps for an industry of failed quality. Solution: consistently make better cork closures.

This argument is recycled every few months or so. It never gets any better. Screw caps have their issues, but the environment is not one of them.

What gets me most in these articles (not necessarily in this article, but in others I’ve read) is that research that is quoted to show how screw caps are hurting the environment is funded by - you guessed it - the cork industry!!! Surprise surprise!

Gents,

The article reports that a screwcap’s carbon footprint is 24 times that of a cork, and that is a pretty serious difference of magnitude, if the article is correct on this. The blather that the cork industry is paying for the pro-cork forest advertising campaign is rather silly- who do you think paid for all the pro-screwcap promotions currently and in the past- the aluminum industry. The research to date is overwhelming that SC taints more wines than natural cork today (for any who can be bothered to read it), and the reality is that wineries use it because it is cheaper than corks and improves their bottom line. Any other stated reason is simply a smoke screen to cover the fact that they are trying to save money with the closure and increase profitability. Nothing wrong with that of course, if the closure is not screwing up the wine in the process, but unfortunately as of today, it continues to do so.

Fortunately, most consumers drinking screwcapped wine cannot spot a wine tainted by reduction (a majority probably cannot spot a corked wine either), so of course wineries selecting to use SC hope that the closure can be fixed to stop its propensity to reduction before John Q Public figures out what a wine tainted by reduction smells and tastes like, so that the increased profitability from the use of the closure can be locked in on into the future. But if I were a product liability attorney, I would not hesitate to delve into this issue, as the research out there is overwhelming that the closure is flawed and that this has been generally known within the industry for quite some time, and yet wineries continue to use the closure. (Not the pro-SC wine columnist for the Telegraphe adding his two cents that the closure is fine for young reds and whites.) Add to the equation the use of heavy metals in some countries to try and put off the day of reckoning and you have a potential payday for the enterprising law firm that will look like the Christmas to end all Christmases.

John, from what I’ve read reduction and TCA taint occur at about the same rate with their respective closures. Hasn’t there been research done to determine how to reduce the possibility of reduction?

Also, I’m not sure how heavy metals factor into the Stelvin closure. There’s a liner between the wine and the cap. Are you suggesting heavy metals are in the liner?

Finally, I don’t think when it comes to high quality Stelvin closures that they are any cheaper than corks. There are many types of corks, and there are many types of screw caps. I’ve found the composite corks tend to have a glue smell when I pop open a wine bottle, though it’s not noticeable once the wine is poured. With other cheap corks, anecdotally, I find a higher incidence of corked wines. While the best, most carefully selected corks do the best job, they probably aren’t worth the cost for everyday wines.

I’m curious exactly what the cost “footprint” difference is between the two? Just how much of a bottom line advantage is it to go with with the screws? My guesstimation is that the difference is little.

John,

I truly beg to differ that all companies are using screw caps just because of cost . . . If that was the case, they’d use synthetics - they ‘look like’ corks and are A LOT cheaper than most screw caps.

As far as ‘faulty wines’ go, I beg to differ as well - I ask wherever I go, and there is not systemic issues at this point. I ask somms at nicer restaurants when I go - same reaction - nothing negative.

Just a divergent viewpoint here . . .

Cheers!

Found this interesting:

Natural cork closures have a centuries-long heritage; however, they allow for a bottle of wine to be “corked” as the saying goes. A “corked” bottle has a musty smell and taste that stems from TCA (2,4,6-Trichloroanisole) - a substance used to sanitize the natural cork prior to bottling. The result is a flat, moldy flavor devoid of fruit-filled taste and aroma. It is estimated that about 5-10% of wines available on merchants’ shelves are “corked.”

Synthetic corks, derived from plastic, appeared to be a viable alternative to traditional corks. However, their track record has been tarnished due to their inability to keep oxidation at bay for any real length of time, significantly decreasing the shelf life of a wine and short-changing the maturing process of select wines.

Screw caps provide the best seal for bottled wines, and eliminate the “corked” and oxidation problem in one fell swoop. Hogue Cellars completed a 30-month study comparing natural and synthetic cork closures with the Stelvin screw caps, their findings suggest significant benefits in utilizing screw caps over either natural or synthetic cork closures. While, screw caps do diminish the drama and romance of bottle opening it is well worth the sacrifice to ensure a taint-free wine that offers consistent aging, maintained flavor and freshness with optimum quality control.

The 7 Best Wine Openers in 2023: Expert-Tested" onclick="window.open(this.href);return false;

Hi Greg,

You are right that the SC industry is feverishly at work trying to figure out how to replicate natural cork’s properties for gentle oxygen ingress during the first couple of months that the cork is put in the bottle, and then its tapering off its oxygen permeability over the ensuing months and years. It seems that this performance works beautifully to obviate most wines’ tendency towards reduction. But to date, the SC industry has not yet been able to replicate this performance characteristic of natural cork. I am sure that one day they will figure this out and the closure will offer dramatically better performance as a wine seal than is currently the case.

I have not seen any recent data generated through clinical research on the percentages of reduction taint in wines sealed under SC, if indeed there has been any studies done, so I cannot comment on their performance in the realm of reduction vis a vis natural cork’s performance in regards to TCA taint. But in terms of TCA taint in natural cork, industry leaders like Amorim have dramatically reduced the amount of TCA taint in their products over the last 10-15 years (their record prior to this was as abysmal as even the staunchest of SC proponent will contest), and the research I have seen shows the numbers for TCA taint well below 1% these days for all corks produced at Amorim. Ironically, the Diams, which are some of the cheapest corks out there, actually have the best performance in terms of TCA taint (virtually zero), but they are not as aesthetically appealing as a top grade, single punch corks, and hence are not being used (yet?) for most top end wines. However, William Fevre in Chablis changed over all of their village and premier cru bottlings to Diam with the 2007 vintage, so perhaps they are making inroads into higher end wines.

In terms of SC reduction taint, I can only add anecdotally my recent experience with wines sealed under the closure for an article I wrote on Edmunds St. John’s wines. I had eight bottles of ESJ wine sealed under screwcap, with six showing signs of reduction on either the nose or palate, and two performing well and showing the wine optimally. The reduction issues ranged from sulfur-generated off-putting aromas such as burning rubber and cabbage, to impressions of metallic minerality on the palate, pinched palate impressions and clipped finishes. Of the six bottles showing reduction issues, four were undrinkable. In contrast, of the twenty ESJ bottles that I tasted sealed with natural cork (ranging from the 2007 vintage back to 1994), not a single example was TCA-tainted and all showed extremely well. So at least in terms of this small sample, the natural corks rather outperformed the SC-sealed wines.

I should note that two of the SC bottles was emptied and I poured the unused portions of the cork finished ESJ wines into them to save for cooking. Seven weeks later, those bottles resting in my cellar showed no signs of oxidation and made a superb sauce, so clearly SC has its place in my cellar these days.

In terms of heavy metals with SC, it is common knowledge in the industry that in Australia and New Zealand wines to be sealed under SC are routinely “copper-fined” with copper sulphate to put off the onset of reduction once the wines are sealed under SC. The Australian Wine Research Institute has recently published a long paper warning vintners against a too aggressive regime of copper fining, as well as inaccurate calibration in “blue fining” with Potassimum Ferrocyanide (used to remove excess residual copper post-fining) underlining the potential health threat of residual cyanide in the wine post “blue fining”. We went into all of this in quite some depth a year ago on this board, so you may be able to dig it up in the archives. If not, I can happily point you to the scientific papers published on these issues over the last few years and let you draw your own conclusions.

All the Best,

John

John, thanks for the explanation. I’m certainly not one to advocate for long-term aging in Stelvins at this point. Research indicates that there isn’t yet a liner that matches an ideal cork in its oxygen transmission. For age-worthy wines, it certainly makes sense to spend the extra bit to get a top quality cork as that’s as important as the raw material inside the bottle.

I’m aware that copper is used as a fining agent to remove hydrogen sulfide and perhaps mercaptans as well. I was not aware that Australia and NZ abused it. I guess that’s just another reason to avoid Australian wines, aside from the pathetic quality and overripe style. I wouldn’t blame Stelvins, though. I’d blame the producers for manipulating a product that would be better off being distilled into hard liquor. Usually their alcohol levels get them about halfway there from the start!

If you’re worried about carbon footprints; both screwcaps and corks pale in comparison to the glass in bottles.

To start off, I’m not neutral in this argument because my company is the one developing the controlled-oxygen liners for screwcaps. I definatley have taken a side and it is based on the assumption that wine quality is more important than the cork tradition. If you disagree with me on that then dont expect to see eye-to-eye with me on the following.

With my bias out there, also understand that it is my partisanship that has caused me to look pretty hard at the environmental claims presented. I’m an environmentalist and I’m sure not going to produce a product that pillages the landscape - so this claim is important to me.

Fortunately, as I read through the report, I found what I expected: Highly biased assumptions that favor the client who commissioned the report which if they were more balanced would quite easily favor the screwcap.

The environmental study was comissioned by Amorim and done by price waterhouse coopers. The thing is 126 pages long. You can find it on the cork industry’s own site, so if you want to argue what I am about to say, please feel free to look it up yourself:
corkfacts.com - Diese Website steht zum Verkauf! - Informationen zum Thema Wine." onclick="window.open(this.href);return false;

You can read that study (though I wouldnt suggest it) and you will find a number of significant biases. My brain turned to mush pouring through the thing, but some of the most glaring biases are:

1. The analysis does NOT include an analysis of the impact of the tamper-evident foil used for covering the cork. The whole point of a Life Cycle Analysis (LCA) is to provide an apples/apples comparison. Corks and synthetics both require a capsule over the cork as protection against tampering. Screwcaps have their tamper-evidence built-in and do not require a capsule.

This omission alone should swing the analysis pretty far towards the screwcap - but let’s continue

2. The LCA takes credit for the carbon-sink effect of the cork forrest. In essence, they are saying that if we do not put corks into wine bottles then the cork forrest will stop consuming CO2.

What is stunning is that this bias is called out in the peer review of the LCA itself (page 62 for those of you who are reading along)

"It is abusive to consider that the carbon capture of the oak forest could be, even indirectly, attributed to Corticeira Amorim"

No shock that this objection has been ignored and the claim is more fervently repeated by the industry than ever before.

Lets put reason into this argument:

The only way to stop the cork forrest from capturing CO2 is to both cut it down, and ensure that nothing else grows in it’s place.

Who’se hands would be on that chainsaw? Portugese cork farmers, including Amorim.

If you look elsewhere in the cork industry’s own “green” publications they talk about how those forrests are currently protected by law.

So for the environmental danger that is threatened to manifest itself, they would have to first change the law, and then cut down their own trees.

Here is the kicker: What is the crop they might plant instead of cork oaks? Other fast-growing trees for paper pulp production… Yeah, those plants sequester MORE carbon than the slow-growing oak…

This argument is more than self-serving - it is bordering on eco-terrorism: “Buy my corks - or I’ll cut this baby DOWN!”

3. The study uses the worst-case scenario for considering the environmental impact of aluminum

a ) The assumption that 100% of the energy required for refining aluminum comes from non-renewables
b ) The assumption that cap aluminum is not recycled, and that only 1/3 of the source aluminum comes from recycled sources

Again, the peer review points out in many places where the assumptions about recycling screwcaps were ignored.

I could go on for a while with this, but those are the three ones that get my ire raised the most.

You can call this report and the environmental activities a number of things, I prefer the terms “greenwashing” or “lying with facts”

Either way, the non-partisan data about cork failures puts the cork failure rate at 5% - between cork taint, premature oxidation, and reduction.

It is a myth that corks let in a moderate amount of oxygen. If you average them, that might be true, but in one batch of corks you will get some that let in almost none, and some that prematurely oxidize the wine. In fact, Richard Gibson in australia has a presentation that shows that 45% of all corks LEAK - that is fail a pressure test, so if there are temperature swings the thing will be pumping air into and out of the bottle.

Thinking about the “average” cork’s performance is an abuse of the notion of average. The truth is that only a very few corks perform near this average - the rest are scattered all over the map - and ALL objective study of cork oxygen performance backs that up.

The final thing I’d like to say is this: The wines ruined by cork have been estimated to be of value on the order of $10 billion per year. The cork industry is asking consumers to eat $10B worth of defective products so that they might not feel motivated to cut their own damn forests down.

I’m sorry, I don’t have much sympathy for that argument. I’ll be donating a fraction of the money made by my screwcap technology to help protect the environment - and it will be a much more effective than giving into eco-blackmail.

Cheers!

Tim,

Thanks for your observations about the report. I have a number of wines in my cellar bottled under screwcap, and I have high hopes for their positive development with age. But of course the concerns John Gilman voiced about the development of reduction worry me as well. Since you appear to be at the center of the issue, perhaps you could clarify something for me. In your post, you stated that:

If that is the case, how do you/did you determine the ideal model of oxygen-ingress for your controlled-oxygen liners? Surely the goal is to emulate the aging performance of the best possible corks while avoiding TCA taint. But if cork performance is so random, how do we know what the determining factors are in positive aging?

That is in fact an EXCELLENT question - and one that I have done a considerable amount of work in answering.

The short answer:

There is no single “optimum” amount of oxygen - variances in wine style, variety, vintage etc are too broad. Instead, we have specced the range of oxygen rates that winemakers might want and give them the choice. On a wine-by-wine basis, only the winemaker can make that selection - and I wouldnt want it any other way.

The long answer:

If you look at post-bottling oxidation from the more pragmatic stance of SO2 management, then the range of oxygen rates can be determined:

1. We know that the average bottling SO2 level of a wine is 30ppm. (this is from my 12+ years in the CA wine industry)
2. We know that in model wine studies 1ppm of oxygen can lower your free SO2 by as much as 4ppm
3. We know that a wine will allow acetaldehyde to survive in equilibrium somewhere around 10ppm free SO2.
4. We consider that the ability to smell a wine as oxidized (aldehydic) is the official end-of-life for the wine.

So by logic, we can say that you can allow 5ppm of oxygen into a wine, but after that, it’s life is dependent on the wine’s own ability to absorb oxygen. Heavier wines will absorb more, lighter wines less.

Given that wines are not expected to be “perishable” (they dont have expiration dates) we feel that at the very least the consumer has the right to safely hold on to a wine for 5 years and in fact see an increase in quality over that time.

So 5ppm over 5 years = 1ppm O2 per year.

On the other side of the equation with concern to reduction, the tin screwcaps let that same 5ppm in over the course of 150+ years. The Saran screwcaps are surprisingly inconsistant, but range on the order of 40 to 80 years for that same 5ppm.

Given these observations the relevant range is easy to define: Certainly nobody is going to complain if a wine lasts “only” 10 years. And in fact, the wines most likely to be put down deliberatley for this purpose are those that are the most tolerant of oxygen exposure.

So we have targeted the range of 1/2 to 1 PPM of oxygen per year. Heavier wines with a 5 year closure will probably age for 10-20 years gracefully and with no ill-effect, and lighter white wines can select a 10 year closure that will let them age gracefully without overdoing it.

That said, if winemakers want more or less than this range, we will give them that!

I hope that was complete information overkill…

Tim - great input. But let’s not neglect the carbon footprint of packaging and shipping.

Screwcaps are a complete product. They are sturdy enough to be shipped in a single cardboard box without any internal structure - just like cork. Basically a cardboard box with a plastic bag filled with screwcaps. So up to this point corks and screwcaps are about equal.

But as you point out, corks need capsules. While they’re about the same weight as screwcaps, they aren’t as rigid, and therefore need a plastic tray to keep their shape. So not only do you have extra packaging, you have double trucking. Not very environmentally friendly.

Tim,

Thanks for the info. Timely since I red this malarky earlier today about the cork pimps use of Facebook:

http://tinyurl.com/24g4rch

Robert

I’m an agnostic on this issue, but for sake of accuracy I believe you are forgetting a quite corked bottle of 2005 Rocks and Gravel. And I’d be hard pressed to say the '99 Sangiovese (cork finished) didn’t show as old (no clue whether just age or cork failure, but definitely some oxidative notes).
I did think the 2008 Porphyry showed quite poorly from reduction, though air made it a bit better. None of the other screwcaps (I believe 5 at that particular tasting) showed poorly for me (but I admit I’m not very sensitive to reduction).