Tuesday, May 25, 2010

Put a cork in it!

I’ve been trying to find some good information out there on different types of wine closures. There has been a LOT of online chatter surrounding corks and screwcaps, etc. of late---lots of opinions flying about. I haven’t been able to dig up anything that didn’t seem to be distorted in some way by the producer of the closure itself---no truly well-done independent study. If you have one, I’d love to see it! So, in lieu of this, I started asking around. The information below is from a long-time wine pro who asked if she/he might remain anonymous. So here you have it:

Natural corks are the best but they need to be pure ones (made in one piece) and patiently selected. A good cork (sorry, a serious one) costs a lot of money (€1/1.30) and should be over 1 inch long (1 ½ is perfect).

For cheaper wines I allow the producers to use T4 as a safe solution. A T4 has a bottom and a top that are one piece and the middle is glued together. The problem is how they glue together the parts because the use of non-neutral glue or improperly washed cork can become a problem (TCA is more often from improperly washing the corks or wineries floors than not from unclean barrels). If there is a problem with a wine we swap the bottles but we also need the cork back. If we are talking about pure natural wines, cork is the choice for the simple reason that is impossible to have a natural wine stable for vintages younger than 2007 in 2010 (at least a cold stabilization and/or a filtration needs to be done – a silicone stopper would be too risky as the wine easily spoils in 3 years).

Silicon works for wines that you do not age and plan to drink in 2 years max. The reason? Silicon doesn’t have a so-called “memory”. Practically speaking, even when it does not crystallize externally, when you squeeze a silicon stopper in, it is going to shrink and shrink and shrink and then it becomes “loose” in the neck of the bottle. Some producers try to use them with me and will usually stop when I threaten them to send the wine back or I show up at their premise with an ax. In that case the wine oxidized (if was alive) or it doesn’t – if the wine has been already taxidermized (see below on screwcaps)

Glass can work but if the wine is meant for long ageing they need to put “this wine has become ‘inert’” on the label. (See below under screw cap.) Plus it is very difficult to do it right. Bottles are not perfectly equal in dimension in the neck and a difference of a micron can make all the difference. The cost of a closure like that and effectiveness is usually not worth it.

Screwcaps are air-tight. So if you put a living wine with a screw cap you will get the typical rotten egg flavor (as it is reduced by the lack of oxygen). In order to avoid this you need to “kill the wine” with sulfur dioxide, nitrogen during the process and usually this is the key… a practical pasteurization. Do not look at me like this… they have to. Particularly if you have a winery that works with more than 6 tons/ha they need to stop the malo (practically do a partial) to keep the wine together and the only way to do it is to kill any little cute bacteria inside … oh yeah and then they write on the brochure they have been growing grapes following a natural process… but they sent them to a concentration camp after and then if you do some more research you discover that they do not even own vines… better if I stop here

And that is the end of my friend's comments...

For your reading enjoyment, here is a google search of Wine Closures.

In my search for images, I found that a lot of people have spoken on this in the past and I would certainly love to link to your blog if you have a post on various types of wine closures! Leave your link in the comments. And by all means, I would certainly love to hear from winemakers on this and even collectors. What have your experiences been with the different closures?

I should have a nice post from another winemaker to put up very soon. Thanks for reading. I hope you'll join in the conversation!


---Wine Ophelia
photo credit: I have no idea. If you own it and want me to take it down, just tell me. :o) cheers!


  1. Very nice read. I tend to think screwcaps are on 'cheap' wines but I've been realizing that is not the case! That was a good little tutorial.

  2. Raelinn - I like the take from your anonymous industry insider. Great to hear. My friend, Sean at WAWineReport.com did a great job with a three part series on the subject. Here is the link to part III



  3. I gotta say I'm a bit surprised at some of your insider's comments. Inert? Not so, the composition of wine is such that it can age, morph, change, whatever you like on it's own. It doesn't need a large dosage of oxygen. One thing the insider doesn't say is that Corks aren't the same. All your ten year old CA cabs, same winemaker with different corks, are going to age differently. Just a fact. Screw caps do allow for the least amount of oxidation, so the wine is preserved longer, they will allow the wine to age in away that preserves the aromatics much better. I would recommend reaching out to some in the business like Rollin Soles at Argyle, or Chad Johnson at Dusted Valley, they'd have a lot to say about this person's assertions.

  4. Great post and some surprising opinions. I've been trying to figure some of this out lately too in my post on Closures.

  5. Always an interesting topic - closures! I've certainly got lots to say about it!!! :

    - Firstly, the 'cork taint' epidemic that is afflicting the wine-world. I'm sorry, but I think this is a conspiricy theory started and spread by producers and mongers of screw-tops and plastic! Think about the bottles of wine YOU buy; how many of them are corked? 1-in-10? 1-in 20? No way! In my personal experience and that of my immediate circle of friends and family who buy wine, I've maybe come across a corked bottle once or twice in 20 years!!! Basically, I'm saying that these 'statistics' of X% of bottles being tainted are a complete fabrication!

    Secondly, think of the environment! Do we really need another plastic, petroleum-based product, that pollutes the environment more (both during its manufacture and its disposal). Meanwhile, cork oak tree forests are sustainable, maintain biodiversity, and provide skilled jobs for real people; as opposed to making a quick buck for shareholders of a polluting plastics company!

    Please excuse my radicality today, but I'm in no mood to tolerate polluters and I resent having to pay for their actions (via my tax dollars), and I shudder to think how much it's going to cost our children and future generations to clean up the mess!

  6. Thanks for posting up your link DCPatton. And thanks very much for sharing your opinion as a winemaker Vinos Ambiz! Much appreciated!!

  7. I think you should have sought someone else's counsel.

    There's lots of good material on closures available online - you need to search a bit smarter. Look for the Australian Wine Research Institute's various publications - they have done the benchmark trial in this area. Look for Paulo Lopes' papers on oxygen transmission.

    I have written a fair bit - including a couple of articles for wines and vines in the USA.

    Errors: 1, silicon is never used to make corks with. Synthetic corks are made from plastic. Extruded synthetics are the best, but oxygen transmission can be an issue.

    2. Glass stoppers (presumably vino-lok) are not hermetic seals - they allow some oxygen transmission.

    3. Even sealed hermetically the wine will develop in bottle. It is never inert.

    4. Screwcaps are not air tight. There are two liners. Tin/saran is very low oxtrans. Saranex allows more otr. Wines sealed with tin saran scaps do sometimes show a little reduction, but this is quite rare and it isn't h2s, more likely mercaptan.

    5. synthetics allow oxygen transmission not because they don't have memory, but because oxygen can diffuse through plastic.

    No wonder your friend wanted to remain anonymous.

  8. Whoa! Snark on! I love it! Jamie, thanks very much for taking the time to post your comments. I definitely appreciate it. I wil certainly look at the Australian study and will seek out Paolo Lopes' and your articles just as soon as I can.


  9. Gotta agree with Jamie Goode. You nailed pretty much every single point I would have made.

    I've been participating in a discussion on Linkedin for a week now, and the general consensus is that cork is now only preferred because of its tradition. Though the odd person chimes in and expresses a burst of distaste for screwcaps, the science and statistics point to screwcaps being a viable closure.

    I've also heard from companies experimenting with stelvin closures who say they're getting very, very close to imitating the aging ability of pure cork. Whoever says that you have to kill a wine to use a screwcap hasn't been listening to the right people.

  10. vinosambiz, Only one corked wine in twenty years, you are very lucky or have a very high threshold for perceiveing TCA. I see it seveal times a month.