syn corkThe Drunken Cyclist’s Friday rant last week raises an important point about transparency and the wine consumer’s knowledge of what they’re buying.

In 2012, he purchased a case of quality, mid-priced Loire Valley Chenin Blanc, 2010 Couly-Dutheil Chinon Les Chanteaux, from an importer. He stored it properly, and opened a bottle on New Year’s Eve. The bottle was badly oxidized. Opened another, same problem. He opened them all—all oxidized and undrinkable. Loire Valley Chenin Blanc ages well, especially Loire Valley Chenin, where there is a long tradition of age-worthy wines. Somebody screwed up badly.

There are many links in the chain from bottling line to popping the cork that might be to blame but the Drunken Cyclist rightfully focuses on the cork, a synthetic cork made by Nomacorc:

I have bashed the use of synthetic “corks” before, and this only reinforced my disdain. While some might see synthetics as an economical alternative for short-term storage, I know of no one (other than the manufacturer, possibly) that would claim it is good for keeping a wine any more than a year or two (at most).

This is controversial. Some synthetic corks make a seal so tight that too little oxygen finds its way into the bottle and wines won’t age properly. But you can purchase synthetic corks from quality producers that allow small amounts of oxygen into the bottle thus allowing the wine to develop as expected. The problem is that synthetic corks are extremely sensitive to changes in ambient temperature, more so than traditional corks. In warm temperatures, they will swell and be difficult to remove. In cold temperatures they will shrink allowing too much oxygen into the bottle. Even if the wine is stored in a cool cellar, frequent minor temperature fluctuations can cause the cork to continually expand and contract breaking the seal and allowing too much oxygen in. This won’t matter if you’re storing the wine for only a few months. But over 4-5 years, a synthetic cork damaged by temperature fluctuations will spoil the wine.

You could argue that age-worthy wines should never be enclosed with a synthetic cork. But they do have their place. They are much cheaper than regular cork and they eliminate the problem of cork taint that can also ruin wine. Since the vast majority of consumers drink wine shortly after purchase, it is understandable that some wineries  think it is their best option. But as the Drunken Cyclist points out

There was, however, absolutely no way for me to know that the bottle was closed with such a device. I assumed, since I paid about $25/bottle, that this was a quality wine, ergo could be held for more than a couple of years. I have long felt that since producers continue to use the obsolete foil on top of the bottle (it is pretty much useless), they should have to disclose what type of closure is underneath. Had I known these wines were stopped with a synthetic, I doubt I would have purchased the wine, let alone hold on to them for a few years.

This is the important point especially as economic considerations are likely to expand the use of synthetic corks. Use synthetic corks if you must, but label the bottles or expose the cork so consumers seeking wines to age will know the kind of enclosure they’re dealing with.