Screw top wines being ruined by sulphidisation?

Thoughts?

Millions of bottles of wine sealed with screw tops rather than corks could be ruined by the smell of rotten eggs, experts have discovered.

Tests suggest that more than one screw top bottle in 50 sold in Britain could be affected by the problem, a chemical process called sulphidisation. The figures throw into doubt claims by the wine industry that screw tops are safer and more reliable than corks.

The annual International Wine Challenge event tested tens of thousands of wines from around the world including around 9,000 with screw caps. It found 2.2 per cent of screw top bottles suffered from sulphidisation and other problems connected with the wine not breathing.

The effects leave a whiff of sulphur, likened by some to burning rubber, rotten eggs, burnt matches or stink bombs. Around 100 million screw top bottles of wine a year are sold in Britain and the figure is rising as it becomes a popular alternative to cork.

Almost 90 per cent of New Zealand wines now arrive in screw top bottles. Warren Adamson, the UK director of the New Zealand Wine & Grape Industry, said: "This is the first time any official figures have come out with regard to the screw top's sulphide problems. These are helpful for our producers. However New Zealand wines were only 1.7 per cent affected, below the average."

But a wine taster Martin Isark said: "Although the smelly problem is a small percentage, with over a hundred million screw top wines hitting our shelves that's potentially a big stink."

When I first saw a screw top wine and the campaign that went with them my first thought was, "If it aint broke, don't fix it."

rwj

....The effects leave a whiff of sulphur, likened by some to burning rubber, rotten eggs, burnt matches or stink bombs...

Burnt matches is the result of levels of SO2 being too high. This is the fault of the winemaker and has nothing to do with screw caps. I've had German Riesling in cork bottles with that flaw, in addition to 4 cases of my home made Riesling (but it integrates over time). Hydrogen sulfide (H2S), the rotten egg odor, is a problem that could be attributed to screw caps, but can also be found in wines with corks. It's interesting that if a wine has H2S and is finished with a cork, the winemaker is at fault, but if it's finished with a screwcap, the screwcap is at fault.

I'll take H2S over TCA any day.

-Paul W.

I'll take H2S over TCA any day.

-Paul W.

Not me. A co-worker at a chemical plant I used to work at was almost killed by hydrogen sulfide. From the website: The Agency for Toxic Substances and Disease Registry (ATSDR)
"Just a few breaths of air containing high levels of hydrogen sulfide gas can cause death."
I realize that H2S levels in wine are very low, but I just don't like the stuff.

I'll take H2S over TCA any day.

-Paul W.

Not me. A co-worker at a chemical plant I used to work at was almost killed by hydrogen sulfide. From the website: The Agency for Toxic Substances and Disease Registry (ATSDR)
"Just a few breaths of air containing high levels of hydrogen sulfide gas can cause death."
I realize that H2S levels in wine are very low, but I just don't like the stuff.

Yes, H2S is every bit as toxic as hydrogen cyanide, the stuff used in gas chambers. However, the smell of H2S is so noxious, and we are so sensitive to it, that it's very rare that someone dies of H2S poisoning because they'll smell it and get away (if they can) long before receiving a toxic dose. The one way that people do get a lethal dose is when the concentation goes up gradually, over a long period of time, because we quickly lose our ability to smell it if continually exposed. It's much like how to boil a frog, actually.

Regarding sulfur in screwcaps, my understanding was that Antipodean winemakers were already adjusting their sulfite levels in response to the switch to Stelvin. Certainly, none of the wines I've tried under screwcap have been notably sulfurous (I haven't had any German BAs or TBAs, however, which is where I'd expect to find it most evident).

Mark Lipton

Coming from NZ, I drink a fair few screwcapped wines and I have noticed the odd 'reduced' character, but it is nothing decanting hasn't fixed. Even without decanting, taste the wine the next day, and you wouldn't even know. And I've certainly not smelt any with 'rotten egg' characters. Anyone who has been to Rotorua knows what this smells like.
Sulphide problems have been around for a long time - and it's been said over and over again, "it's a winemaking problem".

Exactly, and it's not inevitable, whereas with cork at the current level of technology there's a certain level of ruination that's accepted by the cork producers.

This is not news, it was reported in the original AWRI study and has been much discussed since.

I haven't had any German BAs or TBAs, however, which is where I'd expect to find it most evident

Just curious, why would sulfurous elements be more obvious in Beerenauslese and Trockenbeerenauslese?

Yes, H2S is every bit as toxic as hydrogen cyanide, the stuff used in gas chambers.

I know what it is like to die from HCN. I used to manage a large electroplating facility, where we used tons of cyanide and hydrochloric acid (HCL) a month. There was no OSHA or EPA then, so we kept the chemicals in open containers right next to one another. Occasionally, someone would drop some cyanide in the acid and HCN gas would billow out.

Men would be overcome instantly and pass out cold. Luckily, we always witnessed them falling, so we could hold our breaths and drag them out of the fumes. Treatment would consist of placing the men on the railroad tracks in the fresh air outside the loading doors. Then of course you would have to listen for trains, which were infrequent. The beauty of cyanide gas is that if it doesn't kill you, it won't hurt you. I guess long exposure to cyanide increases the risk of certain cancers; but of course there is no such thing as long exposure to hydrocyanic gas.

Once I got a good whiff myself. It overtakes your consciousness so quickly and painlessly that you have but a millisecond to get yourself out of the gas or you are out and then dead, unless someone sees you fall. I lunged away from the puff and fell to the floor, and slowly came back. But the gas isn't even slightly unpleasant, as it is made out to be in the movies. So if you ever have a choice, take that or lethal injection. I never could understand how some convicted killers actually chose hanging over these other painless means. Maybe hanging is usually painless, too; but the anticipation of it isn't, at least to me.

[David M. Bueker]

H2S is very handy to keep Pierre Antoine Rovani away! It works better than garlic.

As I said on another forum, this article smells a lot worse than any screwcapped wine.

By the way...just to stop any discussion cold...the one who brought it up on eBob was Zucc!!

[James Roscoe]

H2S is very handy to keep Pierre Antoine Rovani away! It works better than garlic.

As I said on another forum, this article smells a lot worse than any screwcapped wine.

By the way...just to stop any discussion cold...the one who brought it up on eBob was Zucc!!

Was he sober at the time?

H2S is very handy to keep Pierre Antoine Rovani away! It works better than garlic.

As I said on another forum, this article smells a lot worse than any screwcapped wine.

By the way...just to stop any discussion cold...the one who brought it up on eBob was Zucc!!

Yes, fishily a number of the UK newspapers picked up on it with hardly an enquiring mind. Personally I smell the cork lobby at work, but that's mostly down to their track record of spending money on media instead of on the solution to cork taint / failure.

Yes, fishily a number of the UK newspapers picked up on it with hardly an enquiring mind. Personally I smell the cork lobby at work, but that's mostly down to their track record of spending money on media instead of on the solution to cork taint / failure.

It's been running amok in the NZ papers too today. And the Google newswires are full of it. Don't journalists just love to pick up on this kind of story, happily reporting something off the newswires without realising it is a regurgitation of a story that did the rounds months and months ago. And now all the same issues are being raised and the same antagonists are being quoted with the same quotes.
And how did "low levels of sulphidisation in wines, likened by some drinkers to a smell of burning rubber, or spent matches", as reported in the original story, turn into stinky "rotten eggs". Anyone who has been to Rotorua knows what rotten eggs smell like. I open a lot of screwcapped wines and I've never smelt rotten eggs. I cracked a chook egg once, though, and that was rotten. Yuck!

When did they start sealing wine vessels with corks? The Seventeenth Century, right? Or was it during the Roman Empire and revisited much later in France? Anyway, we are still debating whether they make sense.

God knows how long we will debate screwcaps. I used to join in, but I decided to revisit the discussion in a few years. If nothing new has been verified by then, I will probably forget about them.

[James Roscoe]

When did they start sealing wine vessels with corks? The Seventeenth Century, right? Or was it during the Roman Empire and revisited much later in France? Anyway, we are still debating whether they make sense.

God knows how long we will debate screwcaps. I used to join in, but I decided to revisit the discussion in a few years. If nothing new has been verified by then, I will probably forget about them.

You are just an old amphora advocate anyway.

Personally I smell the cork lobby at work, but that's mostly down to their track record of spending money on media instead of on the solution to cork taint / failure.

I'll take the smell of H2S over the smell of the cork lobby and their TCA any day.

-Paul W.

Question for Mark Lipton.
From what I understand H2S is a natural by-product of alcoholic fermentation, and small traces of it can be found in wine. H2S is transformed into mercaptan by interaction with the alcohol. Only if this chemical reaction does not take place will aeration be helpful in eliminating the problem. Otherwise the wine has to be treated only by fining with Copper or Ascorbic Acid/Copper solution. My question is this.
For this chemical reaction to occur is an almost oxygen free environment or an environment with some oxygen present more favorable?

Salute

Question for Mark Lipton.
From what I understand H2S is a natural by-product of alcoholic fermentation, and small traces of it can be found in wine. H2S is transformed into mercaptan by interaction with the alcohol. Only if this chemical reaction does not take place will aeration be helpful in eliminating the problem. Otherwise the wine has to be treated only by fining with Copper or Ascorbic Acid/Copper solution. My question is this.
For this chemical reaction to occur is an almost oxygen free environment or an environment with some oxygen present more favorable?

Salute

Victor,
The presence or absence of oxygen will not dramatically affect this reaction. pH will, though, with lower pH giving rise to a faster reaction. One other point: exposure to oxygen is generally good for elimination of sulfur odors because sulfur oxidizes so easily. I guess that it's just a question of what else oxidizes alongside of it.

HTH
Mark Lipton

Thanks Mark

Salute

Thanks, Mark. For my money, and I've spent a great deal reaching this conclusion:

1. Corked wines never get better, no matter what I do to them.

2. On a very few occasions, I've smelled an off odor with screw capped wines, but after five minutes of swirling, they've tasted fine.

I may have missed some nuances, but gee, nothing like what I've missed with corked wines where the TCA never blows off, or wines that may have been adversely affected by corked wines where I may not have been able to detect TCA.

Lots of sound, not much fury in my book.

[I can't get those two beautifully appearing but corked Pichon Lalande Comtesse from last December out of my mind, whenever this subject comes up.]

I'll take my chances with screw caps any day.

Regards, Bob

NB: as a half a...ed statistician, that quote about millions of affected screw-capped bottles resonates -- how many corked bottles have been affected, would you suppose?

Hint: take their own numbers. 5% times 90% of all wines sold times the number of bottles sold -- quite a large number, I would guess. B.

Is it correct to think that because screw-caps give a “better seal” (almost oxygen-free environment) that the concentration of the reactants (alcohol and H2S) will remain fairly high and therefore increase the chance of the reaction to occur.

Salute

Is it correct to think that because screw-caps give a “better seal” (almost oxygen-free environment) that the concentration of the reactants (alcohol and H2S) will remain fairly high and therefore increase the chance of the reaction to occur.

Salute

More to the point, because of the tightness of the seal, no oxygen gets in to oxidize the sulfides and no H2S can get out. It's generally agreed that wines bottled under screwcap are more reductive, but even that's being addressed by Stelvin and others (who are making screwcaps that allow a bit more oxygen through).

Mark Lipton

This issue would apply to synthetic corks and I would guess even composite corks too.

My experience like other have said is the sulfurie odor dissipates with the bottle open for a hour or so.