Bottle of Wine Cork Vs. Screw Cap – The Weakness of Sealing Wine With Cork

A pristine cork, pulled from a bottle of wine, is an elegant sign of a savory things to come.

But not all is perfect in this world. Overheated bottles or bad cork can ruin a good bottle of wine by allowing oxygen into the bottle.

This happened to us the other night, when we opened a bottle of Chardonnay and noticed wine stains running along the cork.

Sampling the wine, it tasted as bad as the cork looked. Putting the bottle aside, I grabbed a sister bottle and gently pulled the cork to find it also had cork stain, but not as severe.

This one tasted better, but it certainly wasn’t the wine we remember tasting at the winery.

Why does this happen?

Fluid expands when it is heated, and a good bottle of wine is no different. Let it heat up (in a car, in your kitchen) and the fluid has to expand. It has only one place to go, out through the cork where air exits the bottle. Of course, when it cools off, the wine contracts and air will be drawn back into the bottle of wine, interacting with the grape and changing its taste and quality.

The image you see to above is a perfect example of a well stored wine (Firestone cork on the left) compared to two Chardonnay corks pulled from sister bottles of wine (purchased at the same time, from the same winery, last fall.)

You can see the discolored area where the wine pushes up around the cork  where it contacts the bottle. This is the reason your restaurant waiter or wine steward will present the cork to your table guests – giving you the opportunity to verify the wine has not been altered by bad storage.

While tasting in Monterey last year, we spoke with a winemaker about the differences between cork versus screw cap wines and he made a very articulate argument for screw cap enclosures, saying, “Cork was a great technology 200 years ago.” He explained that screw cap technology keeps the wine from interacting with air drawn in through the cork.

The downside to this is the lack of show – there is no pop, no cork pulled from its nesting place. Unscrewing a bottle cap simply doesn’t have the drama of pulling a cork.

So we’ll see where this ends up. After all, whiskeys and hard liquor were all corked at one time, yet they are mostly contained with screw cap enclosures now. With our society’s desire for greener technology, and desire for good wines, we may see more and more screw cap tops on our wine.  Perhaps we’ll see some combination of the two, giving us the show of uncorking a bottle while protecting our wine from heat and oxygen.

Also, we’ve written the winery about the problems they promise replacement bottles. We’ve had wine from them before with no problems and they have replaced both bottles of wine.