Are anti-cork sentiments softening in New Zealand and Australia?

wine science

Are anti-cork sentiments softening in New Zealand and Australia?


One thing I’m noticing in Australia and New Zealand of late: the growing number of producers using cork for high-end bottlings.

This would have been unthinkable five years ago, such was the strength of the reaction against cork, with its problems of variability and taint. Since 2000 in Australia and 2001 in New Zealand, there has been a massive swing towards screwcaps unparalleled in the rest of the world. Estimates are that screwcap use in New Zealand was above 95% at one point, and Australia wasn’t far behind.

The screwcap, wth the pretty much hermetic tin-saran liner (allowing very little oxygen transmission at all), is a fine closure that has served some wine styles well. Lots of my favourite wines are screwcapped.

But some wines taste better under cork, where the cork is sound. Pinot Noir, Bordeaux-style reds, Syrah and Chardonnay all seem to show better younger when they are cork sealed, and I like the way they age under cork, too. [This is my opinion, and others may disagree: all I will say is that wines taste different when aged under closures with different levels of oxygen transmission, and the differences are evident quite soon.]

For a long time, the whole screwcap/cork debate was almost religious in its fervour in Australia and New Zealand. From listening to the discussion over here I’m in NZ now), you’d think that any wine sealed with cork was ruined and that anyone choosing to use cork was an idiot. For quite a while prior to the mass switch to screw caps, it seems cork taint rates here were terrible, and that cork was extremely variable. It’s understandable why people would be so cross when so many of their wines were ruined.

But things have changed. Now, the quality control in cork production is much better. Screwcaps were arguably the best thing to happen to the cork industry: they caused them to up their game. Cork quality is now a lot better, I think, and this seems to be backed up by evidence from large competitions.

I judge in the International Wine Challenge every year, and we keep a check of the faults. For the last two judging tranches I’ve been in charge of the faults table, and I can honestly say that cork taint still exists. We get through a lot of wines – 15 000 or so entries, and two rounds, so more than 20 000 bottles are entered. We have experienced panel chairs and judging teams so I don’t think many corked bottles are missed. The taint rate is, however, reassuringly low: it’s below 3% of cork-sealed bottles these days, with a big sample size. This includes all commercial levels, with lots of affordable wines where the corks will be cheap. Buy more expensive cork and the rate will likely be lower.

DIAM has been an interesting closure for a while now. It’s a microagglomerate cork where the cork granules have been cleaned by critical point carbon dioxide so that there’s no TCA present. It looks good, too, with a cork-like grain. I’ve never had a problem with a wine sealed by DIAM.

And now there are guaranteed TCA-free natural corks: Amorim have introduced the NDtech, where each cork is checked for TCA by a rapid GC-MS process. I found the first NDtech in a bottle I recently opened. It’s an expensive option, but for fine wines it’s worth the extra.

And let’s not forget: top Burgundy and Bordeaux wines are pretty much 100% cork-sealed, and there isn’t a big call for alternative closures in these regions, which are the most famous fine wine regions in the world. Demand for these wines keeps growing. If cork were a total disaster, and some are claiming, then people would be up in arms. They aren’t.

So it’s interesting to see a resurgence of cork for high-end bottlings over here. The other great advantage cork has is that it enables some pretty smart packaging choices, such as wax dipping. This may sound shallow, but when you are charging lots for your wine, then it makes a big difference if it looks special.

[Conflict of interest: None. I don’t earn money from any closure company.]

16 Comments on Are anti-cork sentiments softening in New Zealand and Australia?
wine journalist and flavour obsessive

16 thoughts on “Are anti-cork sentiments softening in New Zealand and Australia?

  1. I agree with those who would like producers who use DIAM corks, to declare so on the back label. Then they (and me)are more likely to make a purchase, with confidence that they are less likely to be let down upon opening. Of course some producers have no back label, so this info. would need to appear elsewhere. I’ve even noticed that a local producer, Nelson’s Seifried Estate, are using DIAM for the closure of their award-winning Aotea Méthode Traditionnelle. 2 or 3 decades ago, a European cork salesman, freely admitted, that since NZ was the ‘end of the earth’, that they had no problem with their conscience in sending us their lowest category of corks!

  2. Interesting post but “below 3%” is still too high in my view. We wouldn’t accept it in any other field – you have to throw out the odd yoghurt or bar of chocolate because the packaging damaged it. Where there’s an option I’d go screwcap or vinolok every time, though I would be curious to do a blind triangle tasting screwcap v. cork.

    As for wax dipping, I’m no sommelier but they seem like a real pain in the ass to open.

  3. We have used DIAM at Folding Hill since our first vintage and love them. Ironically we couldn’t get the glass for our 2016 bottling and had to go to screw cap 🙁

  4. People may not be ‘up in arms’ but I’d argue that many British wine consumers are pretty hacked off about the level of cork taint. On the jancis robinson wine forum, there’s some pretty disparaging stuff on this, born out of frustration with pulling out a cherished bottle only for it to be a failure. See HRH’s own comments about the level of cork taint in bottles of 1855 chateaux at the Southwold wine tasting too.
    It’s not a storm of protest but it’s a serious annoyance.

  5. I’m with Andrew on the wax dipping. It’s something that makes me think twice about buying a wine as it’s difficult & potentially messy to open.

    I’m a big fan of non-cork closures – too many corked or oxidised bottles of white Burgundy in my life (at the prices we pay for these wines in Australia this means ‘1 or more’!). Plenty of Australian producers have continued to use cork for high-end wines thanks to the idea that certain export markets prefer cork (whether this is perception or reality, I don’t know). But then … Henschke’s Hill of Grace is under screwcap and Prue & Stephen put a lot of thought into their choice of closure.

  6. The higher quality cork (that is, 44mm ref 1’s and up) come from the thickest bark which is from the lower part of the trunk closest to the ground. This is more likely to get TCA taint from soil and animal contact. Therefore the higher quality the cork, the more likely you are to get TCA taint – not the other way around. However other cork faults should be lower. Unfortunately as Burgundy can attest to, this is not always the case particularly with oxidation related issues.
    Sales of cork are rising dramatically in Australia – nearly all going to China and generally low end manufactured cork. Screwcaps aren’t declining for wines sold within Australia.
    I haven’t had a Henschke HoG for a while, but I believe it is a VinLok and not screwcap.
    It is interesting that writers continue to push for more manufacturing and chemical interference in cork as they push for cleaner grapegrowing.

  7. I definitely wouldn’t say that attitudes are softening here in Australia. There’s a few producers who have ‘gone back’ to cork (like Brian Croser) but on the whole the practicalities of screwcap ensure that those makers in the minority (save for natural producers where it’s always been cork and nothing else).

    Of particular note is the push back against cork from on-premise (restaurants, clubs, bars etc). In many of these venues they won’t pour anything by the glass it is sealed with cork because of the hassles of locating a corkscrew and checking bottles rather than twisting a screwcap and pouring with aplomb.

  8. Martin, I’m not sure there’s any evidence that higher grade cork has a higher taint rate. The higher grade corks generally have fewer and smaller lenticels, so I think this is going to reduce taint rate. And testing by GC-MS isn’t chemical interference.

  9. Jamie you are right that testing isn’t interference, but longer times in boiling water, greater doses of bleaching agents (chlorine, or ozone or whatever they are using) is. My comment on TCA at higher levels comes from 6 years selling cork and testing every batch – batch only not individual corks. Corks were tested after 24 hours in 14 % neutral alcohol and suspect batches re-tested on a GC spectro. We rejected significantly higher amounts of high grade cork. When I questioned a Portuguese supplier as to why this was, I was given the answer above – so it is second hand information and may not have a basis in truth. The greatest amount of rejected cork was actually sparkling cork (the cork discs are removed from the glued block). I see quite a bit of Champagne and Sparkling Wine with TCA faults, but usually the CO2 masks it to some degree. And generally most people are celebrating and don’t want to cause a fuss.

  10. That’s interesting info, I shall follow that up. Yes, corks are highly treated, but I do know of some producers who use less treated, more natural (darker) corks – although I have no idea of their taint rates

  11. Unfortunately DIAM does have its problems. For me flavour scalping in the cheaper DIAMs. I opened a bottle of Alto Adige Pinot Grigio last night and there it was again the dull spot that comes from a lower grade DIAM.
    Michael Brajkovich MW tells me that DIAM have now almost solved this and if a producer is willing to spend the money they can get a top level DIAM. However by this stage we are talking the same $$$ as a very good cork. From tasting wines from the same white Burgundy producer under the different closures (natural cork and normal grade DIAM), my preference would be natural cork every time, and take the risks associated with that. But also (because I don’t have an issue with low levels of reduced sulphur compounds) I would buy white Burgundy under screwcap before anything else, just because the seal goes around the bottle lip.

  12. I am surprised to see screw caps described as ‘The screwcap, wth the pretty much hermetic tin-saran liner (allowing very little oxygen transmission at all)’ in 2018. There has been a range of different screw caps with different oxygen transmission characteristics to suit different wine types for some years now.

  13. I think that screwcaps with various oxygen transmission rates are superior. I wish all wines were under screwcap. You can also age screwtop wines standing up which is great for some of us without a lot of proper shelving.
    I have had amazing Syrah under Stelvin and all other grapes.

  14. For me, the best way is to use screwcaps. Some might use Vinolok, but the problem is the material which is between the glass.

    I wouldn’t use any cork at all. Ok, it seems that cork taint is not the big problem anymore, but it’s the fact that when a bottle is open, screwcaps make it easy to close it again..

  15. Doesn’t the less than 3% taint rate you quote as judged by the IWC fault clinics include considerably more than just TCA?

    There is a 2017 AWRI Webinar that uses the IWC 10 stats [2007-2016 and 100.000 bottles+] showing fault stats by country [although the countries are not identified] that includes TCA [generally around 1-1.5%] but also, ‘oxidation’ ‘reduction’, excessive phenols, rot, volatile etc.

    Later they showed the 10 averages for natural cork alone over the whole period where the TCA % was around 1% and, later, a trend line from 2007 to 2016 showing a reduction from 1.6% to 1.0%.

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