Simple Solution for Corked Wine

[This is an article by Corie Brown, LA Times, Mar 28, 2007. At best, the technique described can only reduce the cork taint; it can not reverse the damage already done to the wine; in addition, there is some concern about potential health effects of the plasticizers in plastic wrap.]

Corked wine is the ultimate wine disappointment, all the more crushing when the bottle in question is a costly, highly anticipated extravagance. One whiff of old gym socks, the signature scent of trichloranisole (TCA), and the only option is to pour the bottle down the sink. Or is it?

Mel Knox, a San Francisco-based oak-barrel broker who represents French cooper Taransaud, says there is an easy solution, particularly when the taint is relatively mild. In a glass pitcher, wad up roughly a square foot of Saran or other polyethylene plastic wrap. Pour the tainted wine over the plastic wrap in the pitcher. Gently swirl the wine in the pitcher for five or 10 minutes. The more pronounced the taint, the longer the wine should be exposed to the plastic wrap. For stubborn cases, repeat the plastic soak with a fresh wad of wrap.

Test the results, and when the taint is gone, decant the wine into another container. Toss the plastic and enjoy the wine. Polyethylene absorbs TCA like a sponge, says Brian Smith, president of Vinovation, a “wine fix-it shop” that is experimenting with different plastic-filled cartridge filters that can be thrown into cork-tainted barrels or tanks to absorb TCA.

Cork taint is offensive, but it is harmless from a health standpoint. It derives its name from cork closures. The prime cause is a reaction between a mold found in cork crevices and chlorine-containing cleaning compounds used to clean the corks. Its presence also can be traced to wineries where phenolic wood preservatives come in contact with chlorine compounds.

What is Cork Taint?

Cork taint refers to a dank, moldy, musty, or cardboard smell and taste that masks or dominates the fruit aroma and flavor of wine and reduces the overall quality. The source is a particular chemical compound formed by a reaction between mold and chemicals. Infected wines are said to be “corked” or “corky,” and the contaminant often referred to as “cork taint,” although corks are not the only potential source. Molds are often present in raw cork bark or in wood used for barrels or barrel racks, tanks, scaffolding, walls, stairs, pallets, cardboard boxes, or other winery equipment. Ironically, the very chemicals used for keeping the wineries sterile and safe from contamination may be degraded by fungi or molds indigenous to wood products.

Regardless of the source or chemical identity, cork taint imparts an unpleasant smell that tends to dominate all other aroma characteristics of any wine it contaminates. The least offensive and most subtle sign of TCA is wine that has very little aroma at all. The Australian Wine Research Institute demonstrated in 2003 that even a very low level of contamination, as little as one or two nanograms per liter, suppresses positive fruit aroma character in wine by as much as 50%.

Individuals vary in their threshold ability to detect the presence and strength of cork taint; experience can increase sensitivity. The human threshold for detection is generally considered to be above 5 nanograms per liter. The estimated incidence of cork-tainted wine bottles ranges from two to seven percent. The degrading effect of TCA increases over time in the bottle. Because most wines are drunk young, and because most casual drinkers do not recognize the taste, the average drinker is rarely aware of the defect. Experienced wine lovers and collectors report a higher incidence, for they often drink older wines.