Thursday, June 28, 2012

Corks and Screwcaps: The Hatcher Theorem

Chris Hatcher, chief winemaker of Wolf Blass, has long been an ardent supporter of screwcaps, leading the charge by introducing screwcaps all the way up the range to the Wolf Blass Platinum Label wines. He has developed an elegant diagram, which isn’t easily reproducible for this website, but can fairly readily be understood.  On the vertical axis you have aged characters, and on the horizontal (bottom left intersection) you have time in years.  While the two closures are identical (barring TCA taint) for the first year or so, after two to three years you see more developed characters emerging under the cork closure.  While the difference is not great, some argue that the greater expression of age is a good thing, not a bad thing.  Neither Chris nor I accept that argument, but acknowledgement that it is possible to argue its benefit.

Around 10 to 12 years, the aged characters under cork continue to the point where, depending on the quality of cork, the quality of the bottle neck, the nature of the storage and other variables, the aged characters start to take on different dimensions such that no two bottles are the same.  At this point the bottles under screwcap are all identical to each other and the wine enters a plateau that can extend for decades, with incremental changes over time.  There is no ‘Eureka!’ moment, nor is there any ‘drink yesterday’ alarm bell.

Stephen Henschke has added his own views by saying that cork imparts a taste to the wine which can be detected even where it is a barrel-aged red wine, or a barrel-fermented white wine.

Chris Hatcher reduces this concept to simplicity: there is no point in the development of a white wine where the cork provides a closure as good as that provided by a screwcap.  There is much misunderstanding about reduced/sulphidic characters under screwcap: the fault is not the closure, as the vast majority of white wines show no such characters, but the fault of the winemaker in not ensuring that the wine is free from the signs of or precursors of reduction.  Even here there is room for debate: the eminent French researcher, the late Emile Peynaud, often wrote of the pleasant effect/taste of slight reduction. He saw this as simply being the opposite of oxidation. I won’t go further down this track, because it leads into the scientific thickets of the redox potential of wine, and its constantly changing impact.

7 comments:

Joachim Enevoldsen said...

Wine under cork is a strong disincentive for me to purchase wine. I currently have a 7-8 year supply of wine (bit over 1000 bottles). The reason I store wine is the anticipation of how it will drink in 10+ years from now. I'm 32years old. I have wine I want to drink in 30 years time. Under screw cap I'm confident it will be amazing due to the consistency of the closure. Whereas if those wines happened to be under cork it's anyone's guess whether the wine will be great, vinegar or taste like mould cardboard thanks to TCA.

Anonymous said...

"...Around 10 to 12 years, the aged characters under cork continue to the point where, depending on the quality of cork, the quality of the bottle neck, the nature of the storage and other variables, the aged characters start to take on different dimensions such that no two bottles are the same. At this point the bottles under screwcap are all identical to each other and the wine enters a plateau that can extend for decades, with incremental changes over time..."

This is a very good and uncommonly-made point, specially for those who, like me, usually buy wines by the case of 12 and enjoy following the development of an individual wine over a period of years.

It's a common annoyance for me, when coming to the last 3-4 bottles of a case, to encounter one bottle that is showing signs of decay, which leads me to open the next sooner than I otherwise would, only to find that the dodgy bottle was just a dodgy cork and that the wine still has years ahead of it.

Similarly, and even more annoyingly, there have been occasions when I have held onto the last bottle of a case with some anticipation, because the penultimate bottle showed further potential, only to find that my final chance to enjoy the wine has gone, as I watch the corked or oxidised wine go slowly down the sink.

By 2012 - even in the UK - I have been able to age several screw-capped reds and whites for 8-10 years and they are always consistent from bottle to bottle, which in my view is entirely a good thing. I'd even suggest that part of the widespread impression that wines age more slowly under screw-cap is caused by comparing them, either specifically and simultaneously, or just as a matter of general impression, with bottles that have bad corks.

Hartley Beer said...

It is a matter of common observation that a wine cork, left to itself is inert. For example, one that might that sit in a fishing creel, keeping a hook safe does not deteriorate in any way over many years. On the other hand, one that has been used to stopper a bottle of methelated spirits will shrivel up in a relatively short space of time. Similarly, wine that I have stored vertically, for decades (yes, including Hunter Semillon), with no wine/cork contact, is as I write, in excellent condition (baring winemaking faults) untainted by the cork or by oxidation with the cork itself still in perfect condition with no sign of drying.
It follows that wine corks do not taint wine or deteriorate in the 35 years of my cellaring experience unless they are allowed to remain in contact with wine, nor is it necessary to ‘keep the corks moist’ in order to prevent oxidation.
Hartley Beer

Anonymous said...

Thanks for this excellent analysis. All my questions have been answered. Screwcaps in my view are the best available with every bottle tasing as I expect. As Anonymous notes I too have had many disappointments with the last bottle of a case.

Ken Gillman said...

There is a realistic expectation that the near future will bring us the intelligent closure. This is one where the degree of diffusion of gasses across the closure can be adjusted according to desire. It should be possible to allow consumers to do this in their own cellars depending on how they wish to adjust the ageing characteristics of their particular wines to their particular drinking window. Nano-materials technology probably permits this already if a suitable entrepreneur wishes to step forward. Does anyone know if such steps are already under way by someone somewhere?

Anonymous said...

Whilst srewcaps have been a revolution my only gripe is the extended aging process. However this is far outweighed by the consistency from bottle to bottle right down to the last of a dozen that is drunk without facing the prospect of being poured down the sink. The redundancy of both corkscrews and frustration in extracting crumbling cork are added bonuses.

benway69 said...

if you like the formula; 2btls are awesome, 2 are awful, and the other 8 vary= 12bottle case.. you go for it! i find that poorly cellared wines are prevalent and the damage most obvious under cork. ive found this over the past decade of having intimate access (i was a staff member) to a couple of outlets who DONT cellar their wine properly- this has allowed me to do this experiment/research. I was going to do my thesis on it, but to be proper scientific it would have taken too much time and money..least of all the hundred bottles of wine i needed. Takeaway points; listen to Peynaud- wine doesnt need oxygen ingress to age right, bad winemaking not stelvin/screwcaps are causal of reductive odours and maybe.. cork is just what you're used to - get over it, cork is dead.
now about 'accelerated ageing due to suboptimal storage conditions and its role in positively altering wine constitution'..theres a thesis up for grabs 4th years. Im doing mine on 'why the sediment in aged madeiras takes on different textures and shapes that are not statistically related to vintage'..ie. im gonna blame the corks!

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