The Auswine Forum

I cannot help but wade again into these shark infested waters... BUT finally there has emerged a study which at least goes some way to supporting the main concern I have with screw caps: that I always feel they are much more likely to be damaged in handling and transit than with corks, and you may not even be able to tell if this has happened until too late (at, say, the 2033 Sydney Offline)...

"Damaged screwcaps are an even bigger problem for wine quality than cork taint, according to research by one of Australia’s newest masters of wine.

The level of physical damage to screwcaps found in retail outlets was a shocking 26 per cent, while the level of damage severe enough to cause loss of quality in wine was 8.2 per cent – a level higher than generally acknowledged for cork taint.

Much of the damage results from handling in retail outlets. Bottles in presentation racks had the highest level of damage, and large retail outlets were found to have higher levels of damage than small. Damage also occurs during application, packing, storage, transport and unpacking.
The research was done by Alison Eisermann-Ctercteko as part of her Master of Wine dissertation. She found decorated caps were the most susceptible to damage, presumably because the printing process involves heat which weakens the metal.

She also found that plastic-lined caps, such as Stelvin Luxe, are more sturdy, although more expensive. They can carry decorations, logos etc without being compromised. The study is published in Wine & Viticulture Journal Volume 28 Number 5."
Summary courtesy of Huon Hooke, Corkscore Newsletter

I would love to read the full article but its subscribers only, I will see if I can dig it up.

I've always wondered about that. Great post.

Also,under screwcap, how can you tell if the wine has had a good 'cooking'?

WineRick wrote:Also,under screwcap, how can you tell if the wine has had a good 'cooking'?

The cap is slightly domed if it has been thrashed.

I have a hard time believing those statistics though..1 out of 4 screwcaps are damaged? and 8% of the wine has been compromised? I dunno...that doesn't seem to fit right with what I see...

Maybe there are a ton of 5-10 dollar bottles no one cares about or notices that are skewing the results...Has anyone else seen this?

I do like the Luxe caps though..they feel nicer and seem a bit more resistant to damage...but someone told me they're not as consistent tightness wise? Not sure..

I can't recall ever seeing a damaged screwcap in a retail outlet.

The only times I've ever seen damaged caps is once due to poor handling in transit and twice when I've belted the top of the bottle accidentally myself.

Why would anyone buy a bottle with a damaged screwcap anyway?

No one would buy a bottle showing any signs of a dodgy cork so why would a screwcap be any different?

Where is Ms Eisermann-Ctercteko getting this information? From the cork industry in Europe?

I dunno...but sounds like a made up dissertation to get her MW.....My guess is that her data is flawed...I don't think she made up her numbers..but the numbers she had told her something and she made a conclusion...but the flaw is probably her sampling...

Interesting.

I have a couple of questions though

What constitutes a 'damaged' screw cap? What does it look like? How can you identify one? Why can't you (in some cases) identify it until it's too late?

Through what mechanism does a damaged screw cap affect the quality of the wine? And what is the effect that a damaged screw cap has on the quality of wine? Is it something analogous to 'cork taint' e.g. a component of the screw cap seeping in to the wine (a la dinted and rusted tinned food)? Or is it a damaged seal leading to accelerated oxidation? Or something else all together?

Ok, so how damaged does a screwcap have to be to effect quality? I'd imagine it'd need a significant whacking, but then if 8% are faulty because of it, I have to say 2 in 25 bottles I drink do not have noticeable damage to them - so my question is this:

For a wine to be negatively effected by a screwcap, does the damage have to be visible? I would imagine so. If this is then true DON'T BUY WINE WITH A DAMAGED SCREW CAP! simple. Fixed. When was the last time any of you SAW cork taint in a bottle shop?

Panda 9D wrote:

WineRick wrote:Also,under screwcap, how can you tell if the wine has had a good 'cooking'?

The cap is slightly domed if it has been thrashed.

And in winter, in a cold storage situation, that dome will be sucked backed in. So then pop into the Spring Auctions! Sorry for my cynicism but
I've seen, in many arenas of wine presentation, a large number of screw-capped wines looking 'dopey' when in the 'pop-and-pour' situation. I respect those winemakers who've got screw-caps down pat, but there are many who haven't, and perhaps over -use cu++.

I've seen my fair share of dented screw caps. I guess the further they travel, the greater the chance of damage is.

Panda: 1 out of 4 though?

I've seen dented screwcaps...but nothing like 1 out of 4..You figure if they're dented, they're probably not going to sell them...so they're much more likely to switch to Luxe if that was the case...

And 8% failure rate? As in something is wrong with it? I haven't heard/seen that either..by any wineries, stores, etc...

I can definitely see the argument that Stelvin can be damaged..but these numbers seem way off the charts....

I mean, how many bottles have people had from messed up screw caps in here? I rarely ever hear of it..I know it happens..I know it can happen....but we should be seeing a lot more reports of this if that was the case...

No, not one in four. I'm not necessarily agreeing with the numbers there.. but I have always wondered how much of a knock it takes to break the seal.

It's only $8.80 for the article (7 pages)

Just another smear attack at unstoppable takeover of screw cap over cork, total nonsense.
First of all, as one of the posts said, why would you buy a bottle from a shop if it has cap damage? If it is coming thru post and comes out of box with damaged cap, any decent winery will replace it. Besides, I had so many bottles with damaged cap delivered to me (lovely wine delivery service of AU Post) none what soever had any leakage or any compromise of the seal. Oldest ones I have are Marius 2002 Shiraz, for some reason entire dozen had scrapped/dented caps (Roger kindly offered to replace them all but I said I'll see how it goes), so far had 7 bottles out of 12, all of them kept the wine in pristine condition. If you are concerned in any way, just lay the bottle sideways for a while, if it is not leaking, seal is intact, that simple. I’ve just had some Coldstream wines delivered; one had a considerable dent on the cap, kept it sideways for a week, no leak, no problem, not a worry.
Of course I am not claiming that screw cap is un-destructible but most of the damage seen due to negligent handling has no effect on the integrity of the seal.
RIP cork, amen.

I find that wine fridges do as much damage as I'm trying to get bottles to fit. I have managed to dent a few, but like ufo, the dented caps have never given me any trouble wine quality wise. I've only ever had 2 dud bottles of screw capped wine and they were probably just that - dud bottles. That does happen.

About the only drawback with screw caps is the wine can be a bit reductive when it's young, but this does blow off with a good airing.

Crown seals on Sparkling wines should be the next crusade.......

Cheers
Ian

Guys I am enjoying the debate as always, and agree in my view the extent of issues found seemed surprisingly large... but can we try and limit the remarks that tend to impugn the integrity of the author of the paper (especially in a situation where none of us have yet read the full methodology)?

Remember this is someone's 12,000 word MW dissertation, the high point of their professional training...

Obviously the 8.2% weren't actually sampled, the damage just looked significant enough to "potentially" cause problems.

And as people have mentioned, if the cap looks damaged just don't buy that bottle. There is no way of telling if a wine is potentially corked just by looking at the bottle.

I must have 500 screwcap bottles in my cellar and I have never pulled out one with a damaged cap or faulty wine.

can someone please post a picture of a damaged screw cap?

This one appears to have been so damaged it has become completely separate from the bottle

Well, that's just it though...If really there was 8% damaged that bad, surely that would cause some alarms for wineries that need to replace them? Or if 26% were damaged enough for people not to buy them, that in and of itself is a cause for concern.

Sam - It isn't her integrity...As I said, I don't think she made up numbers...but I do question her ability to understand statistics....Wine people aren't stats people...and maybe I'm completely wrong and 1 out of 4 bottles are damaged...but no one has seen any empirical evidence to support that....if 8% were possibly damaged enough to cause issues where the bottle would be replaced, wouldn't wineries be concerned about that? It isn't like they can take it back and reseal....It would, according to the summary, be an automatic for most places to go to Luxe given the costs of needing to replace 8% of their bottles...or even given the remainder of the 26%..some of which is damaged and buyers are ok..but like someone said, if you saw a damaged screwcap you wouldn't buy it...so if you take a stab at half of the damaged bottles are owned by end drinkers already...so half of 18% so 9%...and 9% are damaged in stores..and if you assume half of those get sold cause people don't know...that's still 4.5%...we're looking at 12%+ of their bottles that are "dead".

I fully admit, she could be right and we just don't know....it just seems like from most people's experience, the numbers aren't anything close to that...and certainly you'd have heard something about this before...

sjw_11 wrote:This one appears to have been so damaged it has become completely separate from the bottle

ha. love your work.

sjw_11 wrote:Guys I am enjoying the debate as always, and agree in my view the extent of issues found seemed surprisingly large... but can we try and limit the remarks that tend to impugn the integrity of the author of the paper (especially in a situation where none of us have yet read the full methodology)?

Remember this is someone's 12,000 word MW dissertation, the high point of their professional training...

Does not matter what level of expertise she has, the prejudice will get her nowhere.

[quote="Polymer"]Well, that's just it though...If really there was 8% damaged that bad, surely that would cause some alarms for wineries that need to replace them? Or if 26% were damaged enough for people not to buy them, that in and of itself is a cause for concern.

Sam - It isn't her integrity...As I said, I don't think she made up numbers...but I do question her ability to understand statistics....Wine people aren't stats people...and maybe I'm completely wrong and 1 out of 4 bottles are damaged...but no one has seen any empirical evidence to support that....if 8% were possibly damaged enough to cause issues where the bottle would be replaced, wouldn't wineries be concerned about that? It isn't like they can take it back and reseal....It would, according to the summary, be an automatic for most places to go to Luxe given the costs of needing to replace 8% of their bottles...or even given the remainder of the 26%..some of which is damaged and buyers are ok..but like someone said, if you saw a damaged screwcap you wouldn't buy it...so if you take a stab at half of the damaged bottles are owned by end drinkers already...so half of 18% so 9%...and 9% are damaged in stores..and if you assume half of those get sold cause people don't know...that's still 4.5%...we're looking at 12%+ of their bottles that are "dead".

I fully admit, she could be right and we just don't know....it just seems like from most people's experience, the numbers aren't anything close to that...and certainly you'd have heard something about this before...[/quote]

Spot on.

Scotty vino wrote:can someone please post a picture of a damaged screw cap?

Here they are





See the dent on the left one. The shiny part on right which looks like flash reflection is actually a considerable scratch.

ufo wrote:

Scotty vino wrote:can someone please post a picture of a damaged screw cap?

Here they are

IMG_2013.JPG

IMG_2011.JPG

See the dent on the left one. The shiny part on right which looks like flash reflection is actually a considerable scratch.

is this just superficial damage to the cap or something more serious?

The small dent on the left one is quite deep. When I saw it I thought it would leak but kept it sideways for a week no leak at all. The other one is a deep scratch as if someone help angle grinder against it but again no leak.

Scotty vino wrote:can someone please post a picture of a damaged screw cap?

OK, try this for something a bit more obvious..

sparky wrote:

Scotty vino wrote:can someone please post a picture of a damaged screw cap?

OK, try this for something a bit more obvious..

crikey that's a whack. Has that pierced through?

ufo wrote:The small dent on the left one is quite deep. When I saw it I thought it would leak but kept it sideways for a week no leak at all. The other one is a deep scratch as if someone help angle grinder against it but again no leak.

no leaks is good.