Random thoughts on the world of wine, presented in no particular order.

Thursday, June 11, 2009

Better than bark.

Since the 1700's, wine has traditionally been sealed with corks made from the bark of the cork oak (quercus suber).  Of the nearly 20 billion bottles of wine produced each year, around 80% are still sealed with this natural material, as it's elasticity and impermeability to fluid make it ideal for shoving into the narrow neck of a bottle to provide a barrier between delicate wine and the outside environment.  

Of course, cork has it's issues -- not least of which is the problem of "cork taint."  A chemical, called 2, 4, 6 tricholoroanisole (it's a benzine ring with 3 chlorine groups evenly spread around the ring and a OCH3 group between two of them).  TCA taint can cause wine to smell and taste "off" -- like musty basement, cardboard, or newspaper.  Roughly 5-10% of all cork-bottled wine is affected to some extent (where the flavor and aroma are noticibly changed), and in my experience about 1% of all wine is completely overcome by TCA.  Note that TCA taint has nothing to do with the quality of either the wine or the cork; Haut-Brion gets affected by TCA the same as Ravenswood.

So what to do?  Vintners have been utilizing alternative closures to avoid cork taint (although, in fairness, TCA taint can also happen in the barrel room -- if wooden barrels are used -- it's just much less likely, and will therefore affect a much smaller proportion of wine).  The 4 most popular are the Stelvin (pictured above), the Vino-Lok, the Zork, and crown caps.  Of course, plastic corks are also made, but this blog entry is going to be about the nontraditional, tool-free closures.

The Stelvin closure is also called the screwcap -- it's the most popular alternative closure, having gained significant ground in Australia and New Zealand, with a large number of American vintners using it as well.  It's probably the simplest to use -- if you've ever opened a 2 liter bottle of soda, you can operate a screwcap.  Having the biggest market share of the alternative closures, screwcaps are probably going to be the one that's best accepted by consumers.  

That being said, there are a few issues with them -- primarily that they don't let enough oxygen through, so that can throw the flavor off by being reductive in some wines.  Many consumers also view them as "cheap," primarily due to the fact that Americans were introduced to screwcaps on wine by Ernest Gallo and a little fortified wine called Thunderbird (as Gallo famously said, "bums don't carry corkscrews").  Stelvins also lack the "pop" of a cork leaving the bottle, something that many consumers (including myself) subtly look for in a wine.  Finally, studies by Haut-Brion in the 1970's indicated that after about 10 years, the silicon pad of a Stelvin closure becomes brittle, and can crack, overexposing the wine.

Still, for wine drunk within a decade of bottling (which is pretty much all wines save a minuscule percentage), it's a pretty good closure.  The convenience tends to outweigh the problems.

Next up would be the Vino-lok (pictured here).  This is used primarily in Europe, although at least one Australian producer (Molly Dooker) used it last year.  It's got a pretty small market share -- under 1000 wineries use it -- but it's a good closure on a technical level.  It consists of an aluminum cover over a glass stopper with a silicon pad in a slightly wider-necked bottle.  The seal is as tight as a Stelvin, and you can reseal the bottle with the stopper (although, you can only use the stopper on other Vino-lok bottles).  In fact, resealed, no wine will leak out, even if the bottle is inverted (I've tried this).

On the down side, it's a little more confusing to open, since there's no real frame of reference for it -- and you have to slightly twist the stopper to get it out.  Also, if you reseal the bottle, it seems that when you remove the stopper to reopen the bottle, you always get wine on your hands.  A small problem, but a problem nonetheless.  And, again, there's not much of a "pop" when you open the bottle.  More of a "clink."  Finally, from a vintner's perspective, these are much more expensive than other alternative closures, costing about 70 cents apiece -- about 2 to 3 times the cost of the competition.

That being said, again, it's better than cork.  Glass is as inert as we'll find -- that's why we use it for bottles, after all -- and the resealability is quite nice.  Plus, there's a certain elegance to the glass stoppers -- it's hard to quantify, but I feel that these are just less "cheap seeming" than a Stelvin.

Next up, we have a Zork.  No, it's not named after the old-school text adventure from Infocom (I'm showing my age here, I think...), rather it's a play on the word "cork."  It's made of vegetable-oil-based plastic, and primarily used in Australia, although Don Sebastiani uses it for his Plungerhead Zinfandels from Lodi and Dry Creek.

As you can see, the Zork is opened by peeling back a tamper-evident seal, kind of like on a jug of milk.  Then, the plug is pulled out, kind of like in a bottle of port -- there's a little plastic nub that goes into the neck of the bottle, which provides a satisfying "pop" when the bottle is opened.  Zorks are also resealable.

Alas, I've not found any data on the efficacy of the Zork for long-term storage, nor do I know how well it keeps out air when the bottle is resealed.  It's not a very popular closure, for some reason (and I can't figure out why, really.  But, I know of exactly 3 producers using it -- Plungerhead, Red Knot, and Whoop Whoop), so there's not that much information on it.

This is a crown cap -- some wines are bottled using them, mainly sparkling ones.  In fact, while the bottles are being riddled (the yeast encouraged to go into the neck of the bottle so that it can be removed and the dosage added), it's what sparkling wines are closed with.  Some producers are using them now for their finished wines -- Chandon uses it in California, as will Duval-Leroy with their Maestro closure, and some producers do in Tasmania, and artisan producers elsewhere.

The main problem with this is that it reminds people of beer, not wine, and that it requires a bottle opener (although the Maestro has that built-in).  If the point of using an alternative closure is to eliminate the need for corkscrews, why replace it with another tool?

So, the perfect closure for wine has yet to be found.  The Stelvin is probably the closest, if only we could get over the idea of "screwcaps = cheap," as a wine-consuming culture!

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