Saturday, November 9, 2013

Cork and Other Closures

Recently, I opened my mouth to defend the use of cork in a small gathering where the virtues of screwcaps were being touted. It's not that I don't like or appreciate screwcaps, I do, and it's not like I haven't read up on the controversy, I have (To Cork or Not to Cork by George Taber, but I didn't have the specific information about the use of corks and screwcaps in the United States.
Cork began getting a bad name for itself when bottles of wine were smelling like wet cardboard when they were opened, according to George Taber. The wet cardboard odor was then identified by Hans Tanner and his colleague Carla Zanier, in the 1980s as 2,4,6-trichloroanisole (TCA) and related compounds. The problem was then traced to how cork manufacturers prepared the cork using chlorine products. The use of chlorine turned phenol, a naturally occurring compound in cork bark into 2,4,6-trichlorophenol and then the final insult was delivered microbially when the phenolic oxygen was methylated to produce 2,4,6-tricholoroanisole. This put cork manufacturers on notice that they needed to correct the problem of cork taint. Chlorine is no longer being used as the sanitizing agent and various tests are conducted to ensure that TCA is not a factor in the manufacturing of corks.
In the meantime, the use of screwcaps was on the increase. However, while they are not prone to TCA, screwcaps are not without their own problems that include the production of post bottling sulfides. That is the whiff of rotten eggs that you may smell when opening a screwcapped bottle.
In the November 2013 issue of Wines & Vines, there it was! Given these choices for closures, it was of interest to read that while the use of screwcaps is on the rise in North America with 38% of wineries using at least some screwcaps as compared to 5% in 2004, 84% of wineries still continue to use cork.

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