Corked!

New Zealand wine writer Bob Campbell asked that in a book I’ve been reading about corks called “Screwed”, by Tyson Stelzer. There are many problems with corks as closures for wine bottles, and I’d like to address a few of them today. The wine industry has known about these problems since corks were first used, in the late 1600s. That there has not been, until recently, an acceptable alternative is the only acceptable reason for the silence. With the acceptance of screw caps, there are fewer spoiled wines on the market, yet many people insist on buying only wines finished with a cork.

Corks serve two purposes: to keep the wine in, and to keep air, dirt and other undesirable items out of the bottle. Because cork is made from the bark of an oak, specifically known as Cork Oak, it is a living thing and has flaws and imperfections which can lead to trouble. Most often, these problems can be divided into three areas: Taint, oxidation and bottle variation. Let’s look closer.

Taint occurs when bacteria contaminates the cork and reproduce in the bottle. Wines thus affected are said to be “corked”. The most common chemical compound that this interaction creates is 2-4-6 trichloranisole, and this gives the infected wine its distinct “corky” smell. At first, these wines become dull in flavor, and the fruit tastes simply disappear. At the next step of affliction, the telltale smells emerge: typically described as the smell of a damp. dirty cellar, or old, musty newspapers, or moldering cork. The wine will usually have these unpleasant flavors on the palate, as well.

Some people are more sensitive to the signs of corked wine than are others, and some are simply unaware that an infected wine really is “off”. I have gone to wine tastings where dozens of people, all in the wine business, have sampled a corked bottle and none has picked up on it. If you believe that your wine is corked but you are not sure, ask someone else to smell and taste the wine. In a restaurant, refuse the corked bottle, and insist on another.

Wine oxidizes when it comes into contact with air, and a sherry-like aroma and flavor becomes apparent. When a cork shrinks its seal is broken and wine can exit the bottle while air enters, allowing oxidation to occur. Since corks shrink when they become dry, wine bottles are stored on their sides or upside down in order to keep the cork wet. Wine cellars are kept at 50 – 60% humidity to keep the corks from drying out. (Higher humidity won’t hurt the corks, but will encourage the growth of mold and mildew, staining the labels on your bottles.)

It has often been said that there are no great vintages, only great bottles. This is because of the wide variation from bottle to bottle which older wines show. Even wines stored alongside one another, untouched, in the same cellar will quite often look, smell and taste quite different from bottle to bottle. One may be alive, vibrant, full flavored and brilliant. The next: lifeless and flat. The third: muddied and undrinkable. The only thing different when these bottles left the winery were the individual corks. Nothing else could contribute to such wide variations in the condition of the wine.

Taint, oxidization, bottle variation, leakage, plus other problems such as “woodsiness” or “dusty corkiness”, which is not actually taint… put them together and then add in long-cellared wines (wines kept for longer than 15 years) which often “fail” at a rate of over 30%, and it is easy to understand claims that at least 10% of wine is damaged by the cork. This is the main reason why we are seeing more wines sealed with screw cap closures.

A stained cork does not mean that your wine is bad or spoiled. Often in the winery corks are placed into bottles too-full with wine. Slowly, over a few days or weeks, some wine will leak out of the bottle until the pressure is more neutralized. Since these bottles are stored upside down or on their sides, the cork will be stained. After years as a Sommelier, opening thousands of bottles, my professional advice is this: the only way to tell if your wine is good or is spoiled is to pour some into a glass. Swirl the wine to coat the sides of the glass. Look at the color. Is the wine clear or muddy? Is the color correct, or has your red wine turned brown? Smell the wine. Clean or dirty? Appealing or “off”? If it smells as if the wine is sound, sip it. Move it around in your mouth, even chew it. You’ll know if the wine is good or not. Perfectly good wine may have a rotten cork, while badly corked wine is most often sealed with a flawless cork. Sniffing the cork is useless. Use your senses. If the wine is bad, send it back and try again… and, when you see a screw cap, breathe a sigh of relief.