Interesting tasting last night at the launch of Tyson Stelzer’s new book, “Taming the Screw†, a wine industry technical manual for the use of screwcaps on bottled wine.
On tasting were 8 vintages of Henschke Julius Riesling under screwcap ( 1997-2004), and Charles Melton Shiraz 2002 and Nine Popes 2002 under both screwcap and cork.
Without going into a massive amount of detail, what was of most interest to me was the performance of the red wines under their differing closures. Being an unabashed fan of stelvin/screwcap/ROTE for all varieties of wine, I was quite surprised to find that I preferred the cork sealed versions of both the Charles Melton wines on the night.
I guess there are all sorts of assumptions to be made about the reasons for this, greater oxidation, etc, but the cork sealed versions were softer and friendlier in the mouth and showed a greater level of complexity on the nose( more savoury orientated notes). One other taster there ( studying winemaking at Uni) went further and felt that the ROTE sealed wines exhibited a “tinny†character. Whilst I didn’t quite agree with that descriptor, it certainly indicated to me that quality wines such as these may take much longer to reach their zenith of drinkability in the reductive environment provided by such alternative closures.
ThereÂ’s no question that ROTE closure slows down the rate of aging, but just how much?
ItÂ’s got me thinking too- will we just have cellars full of Peter PanÂ’s, lovely fresh, primary fruited wines that will change very little over our lifetime? IÂ’ve read nearly every research paper on the matter now, and although they all point to wines living longer, last night got me thinking about the evolutionary phases in such matters and just what may eventuate as a result.
Cheers
Screwcap vs Cork- Henschke,Melton and some observations
I drink alot of red and probably 80% are now screwed.
What I find is they need alot more breathing than cork closed wines and by breathing I don't mean just unscrewing the top. If I drink half one day, the remainder invariably looks even better the next day. If I intend drinking a whole botle I normally give it a decent splashy decant, does wonders.
As for ageing, I've had numerous whites from the original screwings in the mid 70s and they've got wonderful developed characters so not sure why reds wouldn't go the same way.
I think it was Glenn Green who pointed us a while back to some independent research that showed screws will age reds at about the same rate as the best corks but without bottle varuiation and the despised TCA.
What I find is they need alot more breathing than cork closed wines and by breathing I don't mean just unscrewing the top. If I drink half one day, the remainder invariably looks even better the next day. If I intend drinking a whole botle I normally give it a decent splashy decant, does wonders.
As for ageing, I've had numerous whites from the original screwings in the mid 70s and they've got wonderful developed characters so not sure why reds wouldn't go the same way.
I think it was Glenn Green who pointed us a while back to some independent research that showed screws will age reds at about the same rate as the best corks but without bottle varuiation and the despised TCA.
Cheers - Steve
If you can see through it, it's not worth drinking!
If you can see through it, it's not worth drinking!
Steve,
I'm a fan of ROTE, and like you, much prefer the reliability of the screwtop to the variation of cork. I've also read the Penfolds study that you refer to, that is 8 years through on a 20 year technical analysis. What it did say was that the best corks replicate screwcaps in as much as they both allow virtually identical amounts of oxygen ingress(0.001 ml per day) into the bottle, thereby providing the circumstances for the wines to age in a similar manner. As much as it didn't please me to find out, in the interests of objectivity I thought it was worth mentioning that the cork sealed wine was, on the night, a more enjoyable drink.
Cheers
I'm a fan of ROTE, and like you, much prefer the reliability of the screwtop to the variation of cork. I've also read the Penfolds study that you refer to, that is 8 years through on a 20 year technical analysis. What it did say was that the best corks replicate screwcaps in as much as they both allow virtually identical amounts of oxygen ingress(0.001 ml per day) into the bottle, thereby providing the circumstances for the wines to age in a similar manner. As much as it didn't please me to find out, in the interests of objectivity I thought it was worth mentioning that the cork sealed wine was, on the night, a more enjoyable drink.
Cheers
-
Guest
Fair call Grant.
I'm a dedicated screwcap person too, but I've had the same experience a couple of times: when served with both, the cork-sealed wine has smelled and tasted better, even after both have been given a long decant. My no-scientific view on this is that screwcaps on red can maintain a sense of bottling-shock for a greater length of time - but that they'll settle down and, in the end, drink better than cork-sealed wines over the long haul.
just how long that haul is will, in some cases, be the interesting thing.
Campbell.
I'm a dedicated screwcap person too, but I've had the same experience a couple of times: when served with both, the cork-sealed wine has smelled and tasted better, even after both have been given a long decant. My no-scientific view on this is that screwcaps on red can maintain a sense of bottling-shock for a greater length of time - but that they'll settle down and, in the end, drink better than cork-sealed wines over the long haul.
just how long that haul is will, in some cases, be the interesting thing.
Campbell.
Brings to mind a discussion with Len Evans,( who is a known supporter of cork)who mentioned the 1979 Petaluma Chardonnay as an example of the Peter Pan syndrome. Some of the vintage was bottled experimentally under screwcap, and his reflection on the difference's inherent were that even though the screwcap lasted much longer, it never attained the levels of complexity that the cork sealed wine did. From his experience, the wine did not evolve in the normal manner under ROTE seal.
Everyone has a viewpoint, and most of them are quite valid and based upon some experience relevant to the argument. I guess time will provide an answer eventually.
Cheers
Everyone has a viewpoint, and most of them are quite valid and based upon some experience relevant to the argument. I guess time will provide an answer eventually.
Cheers
screwcaps
We did a trial with a fairly large tannic red.
At 6 months we preferred the screwcap and then after that, the cork.
Screwcap seems to go tough and hard and even a bit tinny.
Having said that we're still fans of the screwcap for Sauv Blanc and Rieslings. I think its the tannin (whites don't have much).
Found the same thing with other peoples reds.
Cheers
Smithy
home of the mega-red
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Guest
Grant, please keep reporting it as you find it, if the cork tastes better it does. This might be an interesting experiment to look at the two versions of the Melton's in a few years time to watch development and taste.
Whilst many wineries have been doing trial batches of screws for a number of years, it's only now that consumers can cellar both versions of some wines like the Meltons to do their own assessment.
Smithy, interesting to note your observations.
Not sure of the science (sulphur etc?) but I've been told by a couple of screw cap using winemakers that they NOW prepare the wines differently for screws than cork.
Whilst many wineries have been doing trial batches of screws for a number of years, it's only now that consumers can cellar both versions of some wines like the Meltons to do their own assessment.
Smithy, interesting to note your observations.
Not sure of the science (sulphur etc?) but I've been told by a couple of screw cap using winemakers that they NOW prepare the wines differently for screws than cork.
Cheers - Steve
If you can see through it, it's not worth drinking!
If you can see through it, it's not worth drinking!
Steve,
As a rule, I hate corks. They suck. But you have to be objective too in relation to your experience of wine, and not too selective in your reporting.
The current recommendations in relation to avoiding reductive/sulphidic characters in wine under screwcap goas far back as sulphur dusting in the vineyard, and avoiding doing this within 4 weeks of picking. There is a chapter on it in Tyson Stelzer's new book, pretty technical but worth reading for anyone wanting a better understanding of the matter.
Cheers
As a rule, I hate corks. They suck. But you have to be objective too in relation to your experience of wine, and not too selective in your reporting.
The current recommendations in relation to avoiding reductive/sulphidic characters in wine under screwcap goas far back as sulphur dusting in the vineyard, and avoiding doing this within 4 weeks of picking. There is a chapter on it in Tyson Stelzer's new book, pretty technical but worth reading for anyone wanting a better understanding of the matter.
Cheers
707 wrote:Not sure of the science (sulphur etc?) but I've been told by a couple of screw cap using winemakers that they NOW prepare the wines differently for screws than cork.
Steve,
IMO this is the key...
On this thread on the other Forum I pointed out (as did Tyson on the night) that the Julius clearly demonstrated a progressive improvement in Stephen Henschke's handling of the wine under ROTE over the period from 97 to 04.
There is no doubt in my mind, and I understand this is extensively covered in the Stelzer/Grosset/Brajkovich text, that the winemaker needs to make a series of adjustments to their process in order to convert to ROTE...It therefore comes as no surprise that some winemakers will get less than outstanding results from ROTE if they don't make those adjustments.
As Murray has said previously on this forum, ROTE/Stelvin is not a cryogenic seal. NTL if we can encourage winemakers and wineries to make the necessary adjustments to their process and achieve a significant reduction in the incidence of TCA and random oxidation, we will all benefit in the long run.
Cheers,
MartinE
-
KMP
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MartinE wrote:707 wrote:Not sure of the science (sulphur etc?) but I've been told by a couple of screw cap using winemakers that they NOW prepare the wines differently for screws than cork.
Steve,
IMO this is the key...
On this thread on the other Forum I pointed out (as did Tyson on the night) that the Julius clearly demonstrated a progressive improvement in Stephen Henschke's handling of the wine under ROTE over the period from 97 to 04.
There is no doubt in my mind, and I understand this is extensively covered in the Stelzer/Grosset/Brajkovich text, that the winemaker needs to make a series of adjustments to their process in order to convert to ROTE...It therefore comes as no surprise that some winemakers will get less than outstanding results from ROTE if they don't make those adjustments.
As Murray has said previously on this forum, ROTE/Stelvin is not a cryogenic seal. NTL if we can encourage winemakers and wineries to make the necessary adjustments to their process and achieve a significant reduction in the incidence of TCA and random oxidation, we will all benefit in the long run.
Cheers,
MartinE
Bruce Zoecklein has a few pieces on Closures in his Enology Notes that are relatively simple to understand and give some idea of the differences that might be encountered.
Mike
screwcaps
We did the trial on a moderately big 16% with a fair bit of tannin and colour. I know people are saying that its the low level of sulphur compounds (not SO2) that is causing the reduced smell in screwcaped wine.
To which I say bollocks. There is way too many makers making red wines under screwcap that show these charachters.
Are they all missing smelly wines at bottling?
Why is it worse in bigger red wines with more tannin?
Why isn't it an issue in White wines like Sauv Blanc and Riesling?
Why is it more of an issue in wooded whites..... more tannin?
Sulphur dusting in the vineyard went out with Dodo eggs, and no-one uses sulphur in the month prior to harvest as we get H2S in the ferments.
There is a place for screwcaps but I don't think its in big tannic reds!
Cheers
Smithy
home of the mega-red
Smithy,
I was just using some of the stuff from Tyson's new text, relevant info pasted below,
....................In order to produce wines which do not display hydrogen sulphide characters at bottling and do not develop them in bottle, a range of procedures must be implemented, beginning in the vineyard and continuing right through to bottling.
The first priority is to ensure that elemental sulphur present during fermentation is reduced to an absolute minimum. This can be achieved by such strategies as ensuring that vineyards are not dusted or sprayed within about four weeks of harvest, and by avoiding the burning of sulphur discs or wicks to sanitise barrels. Sulphur pellets, pressurised liquid sulphur dioxide, or a 1% solution of sulphur dioxide in acidified water, are effective alternatives. Potassium metabisulphite and compressed sulphur dioxide gas are the most commonly used. Barrels should be rinsed before they are filled to reduce the amount of sulphur dioxide released from the wood. Finally, sulphuring of the wine should be delayed until ten days after alcoholic fermentation is completed, and sulphuring during racking should be kept to a minimum.
Different fermenting yeasts have different capacities for reducing sulphur to hydrogen sulphide, hence a strain should be chosen so as to minimise this. Some yeasts can even reduce sulphur dioxide or sulphates into hydrogen sulphide. Such yeasts should be avoided.
The provision of adequate levels of nitrogen during fermentation is a key priority in reducing the formation of hydrogen sulphide. Modern winemaking and viticultural practices have produced a deficiency of assimilable nitrogen in grapes, which can result in nitrogen stress on the yeast during fermentation. The solution is to make small additions of nitrogen prior to fermentation in the form of diammonium phosphate (DAP). The amount required depends on the amount of inorganic nitrogen already present, but the usual pre-fermentation addition rate is between 100 and 200mg/L. Subsequent small additions may also be beneficial during the first half of fermentation. This has the effect of increasing nitrogen and consequently reducing the amount of hydrogen sulphide produced as a by-product of fermentation.............
.......
In spite of these procedures, there will always be some hydrogen sulphide formed. It is a vital part of yeast metabolism and an inevitable component of every ferment. It is generally removed by carbon dioxide entrainment during fermentation.
Finally, some wine styles should not be bottled too soon after fermentation. Discretion should be exercised on this point, since many wines are bottled very soon after fermentation, and in fact exhibit no sulphide problems. It should be kept in mind, however, that it is immediately following fermentation that a wine is in its most reductive state. Consequently, the wine must be allowed to complete the “oxidative†phase of its development (through barrel, tank or micro-oxygenative maturation) prior to bottling. The racking process for red wines oxygenates the wine and consequently has a significant impact in reducing thiol levels. The quantities of oxygen introduced depend very much on the racking method employed. Traditional racking will generally add between 3 and 4 mg/L of oxygen, while racking via a tank will practically saturate the wine (6.5mg/L).
Cheers
I was just using some of the stuff from Tyson's new text, relevant info pasted below,
....................In order to produce wines which do not display hydrogen sulphide characters at bottling and do not develop them in bottle, a range of procedures must be implemented, beginning in the vineyard and continuing right through to bottling.
The first priority is to ensure that elemental sulphur present during fermentation is reduced to an absolute minimum. This can be achieved by such strategies as ensuring that vineyards are not dusted or sprayed within about four weeks of harvest, and by avoiding the burning of sulphur discs or wicks to sanitise barrels. Sulphur pellets, pressurised liquid sulphur dioxide, or a 1% solution of sulphur dioxide in acidified water, are effective alternatives. Potassium metabisulphite and compressed sulphur dioxide gas are the most commonly used. Barrels should be rinsed before they are filled to reduce the amount of sulphur dioxide released from the wood. Finally, sulphuring of the wine should be delayed until ten days after alcoholic fermentation is completed, and sulphuring during racking should be kept to a minimum.
Different fermenting yeasts have different capacities for reducing sulphur to hydrogen sulphide, hence a strain should be chosen so as to minimise this. Some yeasts can even reduce sulphur dioxide or sulphates into hydrogen sulphide. Such yeasts should be avoided.
The provision of adequate levels of nitrogen during fermentation is a key priority in reducing the formation of hydrogen sulphide. Modern winemaking and viticultural practices have produced a deficiency of assimilable nitrogen in grapes, which can result in nitrogen stress on the yeast during fermentation. The solution is to make small additions of nitrogen prior to fermentation in the form of diammonium phosphate (DAP). The amount required depends on the amount of inorganic nitrogen already present, but the usual pre-fermentation addition rate is between 100 and 200mg/L. Subsequent small additions may also be beneficial during the first half of fermentation. This has the effect of increasing nitrogen and consequently reducing the amount of hydrogen sulphide produced as a by-product of fermentation.............
.......
In spite of these procedures, there will always be some hydrogen sulphide formed. It is a vital part of yeast metabolism and an inevitable component of every ferment. It is generally removed by carbon dioxide entrainment during fermentation.
Finally, some wine styles should not be bottled too soon after fermentation. Discretion should be exercised on this point, since many wines are bottled very soon after fermentation, and in fact exhibit no sulphide problems. It should be kept in mind, however, that it is immediately following fermentation that a wine is in its most reductive state. Consequently, the wine must be allowed to complete the “oxidative†phase of its development (through barrel, tank or micro-oxygenative maturation) prior to bottling. The racking process for red wines oxygenates the wine and consequently has a significant impact in reducing thiol levels. The quantities of oxygen introduced depend very much on the racking method employed. Traditional racking will generally add between 3 and 4 mg/L of oxygen, while racking via a tank will practically saturate the wine (6.5mg/L).
Cheers
-
Guest
a question for winemakers out there.
on the question of brettanomyces, my understanding is that current theory promotes singificant use of sulphur at the crusher, during fermentation, and pre bottling. does this have any relation, or conflict, with the advice above, and if so, does it mean that screwcapped bottles with low sulphides may, if the above practices are followed, be beneficial to brettanomyces action?
I am not qualified, hence the question. I'm likely to be completely wrong.
on the question of brettanomyces, my understanding is that current theory promotes singificant use of sulphur at the crusher, during fermentation, and pre bottling. does this have any relation, or conflict, with the advice above, and if so, does it mean that screwcapped bottles with low sulphides may, if the above practices are followed, be beneficial to brettanomyces action?
I am not qualified, hence the question. I'm likely to be completely wrong.
-
Guest
Hi everyone,
It's great to see a balanced discussion of this issue here, where people can make intelligent comments without being shot down or accused of bias (as they tend to be on certain other forums!). Good to see!
I agree that screw-capped red wines benefit from a longer decant. Grant, I deliberately didn't decant those reds before the tasting as I didn't want to add any unfair bias toward the screw cap. If I were drinking the wine outside of the context of a comparative tasting I certainly would have decanted it.
Guest (please post your name ), your question about brettanomyces is a good one. There is a separate chapter in Taming the Screw on sulphur dioxide levels, and in it I make the comment that red wines can be considered similarly to whites concerning sulphur dioxide levels, "however, higher levels may need to be considered when addressing particular problems such as brettanomyces infection."
There clearly must be a compromise here, in that sufficient levels of sulphur dioxide are require to suppress brettanomyces and other similar infections, but not too high so as to contribute to hydrogen sulphide production. However, it is not as simple as this, since control of both brettanomyces and sulphides requires much more than just the right level of sulphur dioxide. Once the other areas are properly managed it is possible for suitable sulphur dioxide levels to be determined so as to keep both problems at bay.
Regards,
Tyson.
It's great to see a balanced discussion of this issue here, where people can make intelligent comments without being shot down or accused of bias (as they tend to be on certain other forums!). Good to see!
I agree that screw-capped red wines benefit from a longer decant. Grant, I deliberately didn't decant those reds before the tasting as I didn't want to add any unfair bias toward the screw cap. If I were drinking the wine outside of the context of a comparative tasting I certainly would have decanted it.
Guest (please post your name ), your question about brettanomyces is a good one. There is a separate chapter in Taming the Screw on sulphur dioxide levels, and in it I make the comment that red wines can be considered similarly to whites concerning sulphur dioxide levels, "however, higher levels may need to be considered when addressing particular problems such as brettanomyces infection."
There clearly must be a compromise here, in that sufficient levels of sulphur dioxide are require to suppress brettanomyces and other similar infections, but not too high so as to contribute to hydrogen sulphide production. However, it is not as simple as this, since control of both brettanomyces and sulphides requires much more than just the right level of sulphur dioxide. Once the other areas are properly managed it is possible for suitable sulphur dioxide levels to be determined so as to keep both problems at bay.
Regards,
Tyson.
Ok Tyson, another couple of questions for you.
In the text Grant provided, it is clear that special preparations need to be made prior to actually making the wine. Therefore logic says that in reality, the decisiosn weather the wine will be sealed in ROTE or under tree bark plug should idealy be made prior to the wine being fermented.
That being the case, what is your opinion on wineries that bottle a particular wine under both closures, or those that make a decision to bottle under ROTE just prior to bottling?
In the text Grant provided, it is clear that special preparations need to be made prior to actually making the wine. Therefore logic says that in reality, the decisiosn weather the wine will be sealed in ROTE or under tree bark plug should idealy be made prior to the wine being fermented.
That being the case, what is your opinion on wineries that bottle a particular wine under both closures, or those that make a decision to bottle under ROTE just prior to bottling?
Anonymous wrote:Hi everyone,
It's great to see a balanced discussion of this issue here, where people can make intelligent comments without being shot down or accused of bias (as they tend to be on certain other forums!). Good to see!
Tyson.
You only say that cause you don't like to have to put a bullet proof vest on before you post.
BTW, I was right all those years ago when I said on this very forum "we are creating a monster."
Did you ever get to taste that 94 Lawson?-
Guest
TORB wrote:Ok Tyson, another couple of questions for you.
In the text Grant provided, it is clear that special preparations need to be made prior to actually making the wine. Therefore logic says that in reality, the decisiosn weather the wine will be sealed in ROTE or under tree bark plug should idealy be made prior to the wine being fermented.
That being the case, what is your opinion on wineries that bottle a particular wine under both closures, or those that make a decision to bottle under ROTE just prior to bottling?
Hi Ric,
It's good to be back. Far too long between drinks! Too busy writing textbooks of various descriptions!
Hope you're well. Must catch up sometime. I hope to get down to Sydney next month. Maybe a chance of meeting somewhere in between?
OK, to your question...
The chapter in question concludes thus:
"Reduced characters and screw caps
Low levels of sulphides formed in a wine during storage may be oxidised by dissolved oxygen remaining in the wine, or by small ingresses of oxygen through the closure. The imperfect seal of an average cork can facilitate such ingresses, albeit inconsistently. In this way, a closure which provides an imperfect oxygen barrier may provide some level of protection (although inconsistent) in keeping low-level reductive characters at bay. A problem solved by a problem, by accident.
This has led to the suggestion that the use of screw cap closures necessitates more careful avoidance of sulphide compounds in the wine at bottling. Since screw caps faithfully maintain the flavours of the wine, both good and bad, there is an added urgency to ensure that off flavours do not exist in the bottle in the first place.
Closure trials conducted by the Australian Wine Research Institute have seen low-level reduced characters developing in some, but not all, screw-capped bottles after eighteen months post-bottling. These characters are described as “rubbery†or “struck flint,†and while not dominant, they have been regarded as a negative attribute. Factors named as contributing to their development included the absence of copper fining prior to bottling, the strongly reductive conditions facilitated by the inherent sealing properties of the screw cap closure, the addition of ascorbic acid, conventional sulphur dioxide additions, low pH of the wine, higher than usual (but nonetheless within specification) fill heights at bottling (and hence minimal headspace above the wine), and “snow-dropping†of the bottles with solid carbon dioxide prior to sealing.
These same reductive characters were also noted, however, in some of the cork-closed wines from the same trials, confirming that sulphide problems are certainly not exclusive to screw-capped wines. The trial concluded that it is not certain that there is a greater incidence of reduced aroma in screw-capped wines compared to cork-closed wines. In recent times, Australian and New Zealand tastings and wine show results have revealed approximately equal numbers of cork-sealed and screw-capped wines displaying these aromas. A good cork will provide the same oxygen-barrier characteristics as a screw cap, and hence possess the same propensity for reductive characters to develop. Through careful attention to sulphide management, most wines under both screw cap and cork at recent wine shows have not exhibited these characters.
Sulphides can only show up as reductive characters if they exist in the wine in the first place and are not removed. Provided the chemistry is correct to begin with, the wine will not become reductive. Hence, it is vital that the winemaking disciplines outlined above are maintained rigorously, to ensure that the wine is clean and stable before it is bottled. In this regard, winemaking for screw caps should not entail any deviation from the “best practice†already established for corks. Wines with a propensity to develop sulphide characters in reduced environments will do so if placed in such environments, regardless of the closure used. This is a fermentation management issue, not a closure issue.
Part of this management relates also to the questions of dissolved oxygen concentration, fill height and sulphur dioxide levels at bottling. These topics have already been given some consideration in Chapters 8 and 9, but they warrant further comment in the context of sulphides.
The formation of reductive characters has been linked to both the levels of dissolved oxygen in bottle and the levels of oxygen ingress for wines that are prone to becoming reductive. Thiols are readily oxidised, and their levels are not likely to rise if oxygen is entering the bottle. This has led some to advocate the use of screw cap liners with greater oxygen permeability. However, this negates many of the reasons for using screw caps in the first place, and is not recommended.
It is of interest that Australian Wine Research Institute comparisons between wine sealed in screw cap and that in air-tight glass ampoules have revealed higher levels of struck flint and rubber characters in the wine sealed in ampoules. This might suggest that even the very small levels of oxygen ingress permitted by screw caps suppress these characters slightly.
Trials into whether fill height and ullage space influence reductive characters in the bottle have concluded that no relationship exists. There is, therefore, no advantage, as far as reduced aromas are concerned, in bottling with larger ullages.
Comparisons between sulphur dioxide levels and sulphide characters have confirmed some correlation. Reductive characters tend to increase while the sulphur dioxide level remains above a particular “critical†concentration. This critical level is unique for each wine, as discussed in Chapter 9. However, this relationship is merely coincidental and not causal, since both are a consequence of a lack of available oxygen. The presence of oxygen simultaneously reduces sulphur dioxide and thiol levels. If insufficient oxygen is present to drop the sulphur dioxide levels below the critical point, there is also insufficient oxygen to keep the reductive characters below the threshold of detection. Research in this area remains in progress.
Findings such as these reveal that it is not the closure or the bottling parameters which should be the focus in controlling sulphides. Rather, wines need to be made in such a way that disagreeable thiol content is lowered, thus lowering the wineÂ’s propensity for developing reductive characters. The reality remains that no closure can save a poorly made wine. The tighter specifications associated with the use of screw caps should act as a driver for cleaner winemaking. This has already become apparent in Australia and New Zealand, where the occurrence of hydrogen sulphide characters in wines sealed under closures of all types has begun to diminish in recent vintages.
Diligent sulphide management from the vineyard to the bottle is mandatory for all wines under all closures."
Cheers,
Tyson.
-
Guest
TORB wrote:,
It's great to see a balanced discussion of this issue here, where people can make intelligent comments without being shot down or accused of bias (as they tend to be on certain other forums!). Good to see!
Tyson.
TORB wrote:[You only say that cause you don't like to have to put a bullet proof vest on before you post.
Absolutely!
TORB wrote:[BTW, I was right all those years ago when I said on this very forum "we are creating a monster."
Too right you were!
TORB wrote:Did you ever get to taste that 94 Lawson?
Yep, love it. Bought practically every vintage since, but few are up to the 94. I picked the 1998 double-blind the first time I tasted it. Such a distinctive style. By the way, based on tastings 12 months ago, the 2003 will be stunning and the 2002 will be even better - perhaps the greatest ever?
Cheers,
Tyson.
Tyson wrote:
Trials into whether fill height and ullage space influence reductive characters in the bottle have concluded that no relationship exists. There is, therefore, no advantage, as far as reduced aromas are concerned, in bottling with larger ullages.
In all the threads I've read on this subject when discussion has turned to passages of minute qualtities of oxygen, its relation to ullage has been ignored. Is it assumed that whatever the passage of air takes place, it does not affect the level of wine in the bottle? In other words, sometimes the level of wine will not change, even though oxygen is travelling around/through the cork? If so, why would this happen? Atmospheric pressure is surely the same both inside and out? Or is it assumed that changes in (cellaring) temperature will cause the internal pressure to rise and fall, thus causing the passage of air, BUT NOT WINE, past/through the cork?
Logic (not always reliable, perhaps?) suggests that any air entering the bottle somehow will be less humid than that in the headspace. Is it assumed that the oxygen/air leaving the bottle can only do so if it sheds it's 'wine' component on the way back out? So there is oxidation occurring, even though the ullage is not increasing? It seems intuitively wrong, and yet, I have tasted wines with very good fill levels that have been oxidised all to hell - does this mean that no reliable hypothesis can be offered?
Worse, will we ever know? I begin to doubt it, I really do...!
And Tyson, if you do make it down here, it might be good to get some kind of offline going somehow.
cheers,
Graeme
Tyson,
Some of the research I have seen from the AWRI such as :
Flavor ‘scalping’ by wine bottle closures. ‘Winemaking’ continues after bottling.; Capone, D.; Sefton, S.; Pretorius, I.; Høj, P.
would indicate that cork closures are more likely to extract some of the flavours from wine (both good and bad) and hence will not necessarily exhibit reductive flavours to the same extent as those stelvin closed. Your comments above don't seem to agree with that - any particular reason??
Regards
Some of the research I have seen from the AWRI such as :
Flavor ‘scalping’ by wine bottle closures. ‘Winemaking’ continues after bottling.; Capone, D.; Sefton, S.; Pretorius, I.; Høj, P.
would indicate that cork closures are more likely to extract some of the flavours from wine (both good and bad) and hence will not necessarily exhibit reductive flavours to the same extent as those stelvin closed. Your comments above don't seem to agree with that - any particular reason??
Regards
Barossa Shiraz
Hi Graeme,
My comment in relation to ullage was with respect to ullage level at bottling. I have not investigated the relationship between ullage and oxidation during ageing. This would be an extremely complex area to examine, since it would depend heavily on such things as the wine varietal, sulphur dioxide level, oxidative treatment prior to bottling and dissolved oxygen level at bottling.
Sulphur dioxide chemistry is central to this, and quite complex (we've devoted a whole chapter to it in the text, and only scratched the surface). The key to sulphur dioxide as far as oxidation is concerned is the priority of maintaining levels above about 8-9mg/L throughout the life of the wine. As soon as levels fall below this, oxidation increases exponentially. The wine becomes brown and the sensorial attributes associated with oxidation accelerate. For a particular wine, initial sulphur dioxide levels must be set sufficiently high such that the wine never reaches its critical level in bottle. This can be a problem if oxygen ingress through the closure is variable from one closure to the next (as it is with corks).
The result of all of this is that it is quite possible for a wine to look extremely oxidised as much as a result of its chemistry as the amount of oxygen that has entered through the closure.
Cheers,
Tyson.
My comment in relation to ullage was with respect to ullage level at bottling. I have not investigated the relationship between ullage and oxidation during ageing. This would be an extremely complex area to examine, since it would depend heavily on such things as the wine varietal, sulphur dioxide level, oxidative treatment prior to bottling and dissolved oxygen level at bottling.
Sulphur dioxide chemistry is central to this, and quite complex (we've devoted a whole chapter to it in the text, and only scratched the surface). The key to sulphur dioxide as far as oxidation is concerned is the priority of maintaining levels above about 8-9mg/L throughout the life of the wine. As soon as levels fall below this, oxidation increases exponentially. The wine becomes brown and the sensorial attributes associated with oxidation accelerate. For a particular wine, initial sulphur dioxide levels must be set sufficiently high such that the wine never reaches its critical level in bottle. This can be a problem if oxygen ingress through the closure is variable from one closure to the next (as it is with corks).
The result of all of this is that it is quite possible for a wine to look extremely oxidised as much as a result of its chemistry as the amount of oxygen that has entered through the closure.
Cheers,
Tyson.
Hi John,
I hope to see more of you again now that I'm no longer head-down in textbooks but have time to get to tastings again! Hopefully we'll catch up soon.
In relation to the scalping question, the key lies in the fact that flavour scalping by natural corks and synthetic (plunged) closures (i.e. the ones often erroneously referred to as "synthetic corks) is selective. That is, particular flavours will be absorbed and others will not be affected.
Specifically, corks and synthetics have been shown (in the study that you refer to) to scalp such characters as lychee fruit aromas, kerosine aged characters and grassy notes in sauvignon (cabernet and blanc) varietals. Natural corks have also been shown to scalp tca (ironically!!). There is a vague theory that they also scalp some reductive characters, but I do not believe that this has been confirmed.
According to Peter Godden (AWRI), recent tastings (both through the AWRI studies and informal tastings which he has attended) have revealed that reductive faults are just as prevalent under cork as they are under screw cap at the moment.
Cheers,
Tyson.
I hope to see more of you again now that I'm no longer head-down in textbooks but have time to get to tastings again! Hopefully we'll catch up soon.
In relation to the scalping question, the key lies in the fact that flavour scalping by natural corks and synthetic (plunged) closures (i.e. the ones often erroneously referred to as "synthetic corks) is selective. That is, particular flavours will be absorbed and others will not be affected.
Specifically, corks and synthetics have been shown (in the study that you refer to) to scalp such characters as lychee fruit aromas, kerosine aged characters and grassy notes in sauvignon (cabernet and blanc) varietals. Natural corks have also been shown to scalp tca (ironically!!). There is a vague theory that they also scalp some reductive characters, but I do not believe that this has been confirmed.
According to Peter Godden (AWRI), recent tastings (both through the AWRI studies and informal tastings which he has attended) have revealed that reductive faults are just as prevalent under cork as they are under screw cap at the moment.
Cheers,
Tyson.
Tyson,
Thanks for the long answer and whilst its full of information, it does not realy answer the question I posed in my origional post. Here they are again...
In the text Grant provided, it is clear that special preparations need to be made prior to actually making the wine. Therefore logic says that in reality, the decisiosn weather the wine will be sealed in ROTE or under tree bark plug should idealy be made prior to the wine being fermented.
That being the case, what is your opinion on wineries that bottle a particular wine under both closures, or those that make a decision to bottle under ROTE just prior to bottling?
I am not looking for all the technical stuff that goes on prior to bottling, I want to know the possible end result of making the decision late in the game.... please.
Thanks for the long answer and whilst its full of information, it does not realy answer the question I posed in my origional post. Here they are again...
In the text Grant provided, it is clear that special preparations need to be made prior to actually making the wine. Therefore logic says that in reality, the decisiosn weather the wine will be sealed in ROTE or under tree bark plug should idealy be made prior to the wine being fermented.
That being the case, what is your opinion on wineries that bottle a particular wine under both closures, or those that make a decision to bottle under ROTE just prior to bottling?
I am not looking for all the technical stuff that goes on prior to bottling, I want to know the possible end result of making the decision late in the game.... please.
Hi Ric,
The implication in my post was that wines under all closures should be treated with care as far as sulphides are concerned, hence if things are done properly to start with, no difference in winemaking should be necessary for screw caps. Apologies if I did not make this implication clear. I'll try to explain in further detail, as its implications extend beyond sulphides.
This point is an underlying theme of the entire book: If wines go into the bottle in a sound, stable, clean manner, they will remain this way in bottle. This must be a priority regardless of the closure. Ask most good winemakers (who are pedantic about the finer details) what they do differently in the winemaking process for screw caps, and the answer will be, "nothing." Jeff Grosset and Michael Brajkovich are prime examples of this.
If a winemaker is getting everything right to start with, the wine will be fine under a cork or a screw cap. If winemaking is sloppy, sulphur dioxide additions are imprecise, dissolved oxygen is variable or inappropriate levels of carbon dioxide or hydrogen sulphide remain in the wine, problems may result under screw cap. Perhaps the same wine might sort itself out under cork? Perhaps not? Such risks should not be taken under cork, either.
Cheers,
Tyson.
The implication in my post was that wines under all closures should be treated with care as far as sulphides are concerned, hence if things are done properly to start with, no difference in winemaking should be necessary for screw caps. Apologies if I did not make this implication clear. I'll try to explain in further detail, as its implications extend beyond sulphides.
This point is an underlying theme of the entire book: If wines go into the bottle in a sound, stable, clean manner, they will remain this way in bottle. This must be a priority regardless of the closure. Ask most good winemakers (who are pedantic about the finer details) what they do differently in the winemaking process for screw caps, and the answer will be, "nothing." Jeff Grosset and Michael Brajkovich are prime examples of this.
If a winemaker is getting everything right to start with, the wine will be fine under a cork or a screw cap. If winemaking is sloppy, sulphur dioxide additions are imprecise, dissolved oxygen is variable or inappropriate levels of carbon dioxide or hydrogen sulphide remain in the wine, problems may result under screw cap. Perhaps the same wine might sort itself out under cork? Perhaps not? Such risks should not be taken under cork, either.
Cheers,
Tyson.