What would you think if eight percent of the milk or orange juice you bought was spoiled before you even brought it home? If the same percentage of eggs, meat or bread was ruined before you purchased them? Would you think it was time for an investigation of the dairy/OJ/meat industry? Would you keep buying the product, knowing the chance of buying something undrinkable or inedible was that high?
Wine is a delicate product, affected by the temperature it is stored at, and very much affected by how much oxygen gets into the wine during production, bottling and/or via the closure used on the bottle. It can also be contaminated by organic compounds that are introduced to the bottle through the cork.
The latter are some of the nastiest enemies to good tasting wine. The predominant culprit is a compound called 2,4,6-trichloroanisole or TCA for short. Most wine lovers refer to it simply as cork taint.
Cork taint saps a wine of its natural flavor. It is usually detectable as a "wet cardboard" or "musty basement" smell on the wine, and is one of the prime reasons sommeliers present a small pour of a wine they have just opened to a consumer to smell and taste. Sometimes this smell is only vaguely detectable at first, or only identifiable by those of us who are used to encountering it on a regular basis. It will, however, grow in the glass with exposure to air, so that eventually, almost everyone will be able to detect it.
Another issue with corks is that, as a natural product that varies in thickness and other attributes, often in ways discernible only under a microscope, different corks even from the same batch and same tree will let in different amounts of oxygen. As a result, I've had bottles stored for a decade or two under ideal conditions (i.e., in a winery's cellar, since bottling) where different bottles from the same case, tasted on the same day, showed different amounts of exposure to oxygen--all the way from very fresh tasting bottles to quite oxidized ones with little remaining fruit flavor showing.
The estimated failure rate for natural corks was estimated to be about 8.3% in 2007 and 2008, or about one bottle in 12. This is based on statistics kept by the International Wine Challenge, which tastes and analyzes more than 14,000 bottles annually (i.e., about twice as many as I do). About 5% of those faulty bottles were due to TCA; the rest were oxidation and sulphur related faults, i.e., due to too much or too little oxygen entering the bottle.
The cork industry has taken great strides to reduce the level of TCA in corks since then, and claims to have brought the incidence of TCA in bottles sealed with natural cork down to only about 1.3%. Even if that's true--and some, like Wine Spectator critic James Laube, dispute that the rate of cork taint has changed that much, based on their own tastings--I believe that's still too high when there are abundant alternatives that have virtually no chance of introducing TCA to the bottle.
Then there's the fact that corks break down over time, or get soggy from contact with the wine. I don't know how many corks on older bottles I've opened that have crumbled, or broken in half, necessitating lots of skill, and specialized equipment, to rescue the remaining cork so it doesn't fall into the wine. I taste a lot of wine, of course, and it happens at least several times a week for me.
I for one am profoundly tired of spending good money (a lot in some cases) on a wine, only to have it spoiled primarily due to problems with the cork. Fortunately, many other wine lovers with various kinds of expertise (and in some cases, deep pockets) have also been dismayed with this state of affairs, and have developed a number of alternative closures.
What's fascinating is that many of these closures--like screw caps, artificial corks and other stoppers--not only eliminate the TCA that can get into the bottle through a natural cork, they can also moderate the amount of oxygen that gets into the wine over time in measurable ways, giving winemakers much more control than they have had in the past over this important aspect of a wine's development.
I met this month with a representative from Nomacorc, one of the most advanced of the artificial cork makers, and learned a lot from them about "total oxygen management." Their product, which is made from extruded foam sealed in an unbreakable membrane, has been created in different sizes and thicknesses so as to precisely control how much oxygen gets to the wine through the closure over time.
Studies have been done by a variety of entities, including U.C. Davis, the Australian Wine Research Institute and France's INRA, on oxygen management with different types of bottle closures. One of the findings has been that some varieties, like Cabernet Sauvignon, are more oxygen resistant, while others, like Sauvignon Blanc, are highly sensitive to slight variations in the amount of oxygen that gets into the bottle as a result of winemaking practices, bottling, and through various types of closures.
I tasted two otherwise identical bottles of Hungarian Sauvignon Blanc that had been bottled on the same day this past January, one with a Nomacorc artificial cork that permitted little oxygen to enter and the other with one that permitted more oxygen in. I could easily detect which one had allowed less oxygen in, as that wine was noticeably fresher and more aromatic. We also tasted a 2003 California Cab that had been sealed under a prior version of the Nomacorc, and it was still tasting fine--actually quite youthful in its development.
Similar experimentation is going on with screw caps and other types of closures. Screw caps with VinPerfect liners and ZORK peelable plastic closures, for example, also permit a reliable, small amount of oxygen to enter the bottle, much like the Nomacorcs.
I am thrilled when I see wines under screw caps these days. I wish those who bottle their wines under other superior alternatives to cork would also start making that more evident to consumers. As a lover of aged wines, of course, I will be dealing with bottles with natural corks--and the risk of cork taint and crumbled corks--for the rest of my life. It would be great, though, if we all had to worry less about possible cork taint, and were reliably getting better bottles of wine, free from as many avoidable defects as possible.
Natural cork served us very well as a closure for wine bottles for at least three centuries, but I believe its time is up. Much better, taint-free alternatives are now available, and it's time for consumers to embrace and demand them.