WINE…Un-Plugged…UnCorked

For hundreds of years Natural corks have been the choice for wine bottles. Natural corks allow for a certain amount of gas-exchange required to age a bottle of wine however, the substance used to sanitize the natural cork prior to bottling (Trichloroanisole or TCA) can lead to a bottle of wine to be “corked”. A “corked” bottle has a musty smell and taste that stems from TCA and it ruins the taste of the wine. I have seen estimates that 5-10% of wines on store shelves (or perhaps in your own collection) are “corked.”

Synthetic corks are made from plastic. The main disadvantage to them seems to be that these corks allow a fast rate of oxidation which can lead to a much shorter shelf life of the wine.

Screw caps provide the best seal for bottled wines, and eliminate the “corked” and oxidation problem entirely but, I recently went to a vineyard and I talked to one of the guys who worked in the cellars. He told me that when a wine bottle has a screw cap, the wine had better be “ready” for consumption because the natural gas-exchange provided by a natural cork is eliminated.

There are other aging processes in a wine that will still, however, continue in a bottle which has a screw cap. If the wine, such as a cabernet, has a lot of tannin “bite” when first bottled, this “bite” will over time be muted with proper aging in a natural cork bottle but in a screw cap bottle this “bite” may still be present.

Some screw cap manufacturers include a polyethylene liner underneath the cap, and this liner drastically slows or stops the amount of air seeping into the bottle. Without this liner, the screw cap is similar to natural cork, except that TCA contamination is avoided.

What about Box Wine?

A great feature of box wine is that inside the box there is a plastic bag. As the wine is extracted from the spout, the bag simply collapses so that the wine flows freely out of the spout without the need for air to enter. This allows the wine inside the bag to stay fresh for a much longer period of time than wines that get exposure to air (up to four weeks for box wines vs. a few days for a bottle that has been opened).

In the US, both screw cap and box wines have been associated with “cheap” wines. This is primarily due to the fact that the premium wine producers have not provided their premium wines in these alternative formats. In other countries, this does not seem to be a problem. In Sweden, 65 percent of wines sold are in the box format, In Australia, the figure is 52 percent. And in Norway, boxed wines make up 40 percent of all wines sold (I haven’t seen the numbers on France).

I think we will see some changes continue in this area in the coming years. Should be interesting…Cheers!