Rusty’s Wine 102: Wine Bottle Closures

In an October 2004 Food and Wine Magazine, there was an article by Robert Parker called, “Parker Predicts the Future.” Robert Parker stated, “I believe wines bottled with corks will be in the minority by 2015…More and more state-of-the-art wineries are moving to screw caps for wines that need to be consumed within 3 to 4 years of the vintage (about 95 percent of the world’s wines). Look for this trend to be accelerated.”

What about all of these new high tech closures for wine bottles? The proliferation of new types are extremely evident in the wine industry. The other day I was at All Corked Up and a wine distributor showed Vic and I a new bottle closure called a Zork. The ZORK closure, invented in Australia, features all the conveniences of a screw cap. Its claim to fame is that it delivers consistent protection, attractive appearance, and is re-seal ability.

To open a bottle with a Zork closure, you grab the tab where the z is located at the bottom of the cap and uncoil the plastic seal. Once the lower seal or wrap is removed, you pull straight up while twisting. This closure reminds me of a T-cap found on some ports. The only difference is that the part that goes into the bottle is longer on the Zork providing larger surface area for sealing. Another difference from the T-Cap is that the Zork bottle closure seals much tighter.
With the increase of these new high tech closures such as screw caps, Zork closures, synthetic cork, etc., what are the effects on the wines. These new closures are great at preventing oxygen from entering the bottles and I believe that we can all agree that the drink now wines (less than 5 years from vintage) will not be affected. In fact, I believe that the consumer will receive a fresher and more consistent product than those that use natural cork. But what about the wines that we want to cellar. The big cabs, Bordeaux’s, Burgundy’s, etc. How will this affect the development of the wine over time?

The First International Screw cap Symposium, in Marlborough, New Zealand, where Peter Goddon of the AWRI offered this interesting quote, “Closure variation may have a greater impact on wines and wine quality than the widely discussed and debated terroir issues. After about a month in the bottle, wines under different types of closures will never be the same.” He also believes that closures will change wine dramatically, not just at different rates, but they will cause wines to age differently.

Searching for alternate methods for sealing wine bottles was based on finding a replacement for cork as the supply of natural cork is dwindling and the corks are not of the same quality as in the past. Another reason is to reduce the losses of wines that are damaged either by oxidation or being tainted by the cork. Statistics show that 5-10% of wine bottles that use natural cork are “Corked”. A wine that is “Corked” has a musty smell and taste. This is caused by TCA (2,4,6-Trichloroanisole) which is a chemical that is used to sanitize the natural cork prior to bottling. The result is a flat, moldy flavor devoid of fruit-filled taste and aroma. My best description of a “Corked” wine is that it has the smell of wet cardboard.

The choice of which cap to use for bottling is up to the discretion of the winery. Drink now wines may benefit greatly as stated earlier, it will keep the wines fresher and the losses due to tainting from natural corks will be eliminated. The French are holding off as fine French Bordeaux’s and Burgundy’s are made to be cellared and develop for many years.
This brings us to the benefits of corks. One key factor in the development of wines is oxygen. It is true that excessive oxygen will oxidize the wine and ruin it, but a certain amount of oxygen is required to continue developing the wine even in the bottle. I will not go into all of the chemistry as it is very complex. Oxygen in small amounts has effects on color, aroma and flavor through chemical reactions known as oxygen reduction. This can be good and bad and relies on the presence of other chemicals such as sulfur dioxide. Sulfur dioxide slows down the affects of oxidation on wines. Presence and quantity of sulfur dioxide is important in allowing wines to develop over years without losing the fruit flavors and aromas. Sulfur dioxide binds up free carbonyl (i.e., acetaldehyde) compounds produced during oxidation, reducing their concentrations below our sensory threshold. This minimizes the effects of oxidation and deterioration of the wine aroma.

So what are your opinions on new cap technologies? Should only wines below a certain price use these new types of closures? If so, what is that price? Molly Dooker Carnival of Love Shiraz is $80 and they are bottled with a screw cap. Or should it be based on the ageing potential of the wine? As I stated earlier, wines that are produced for consumption within 1 year (or as we frequently see, within a month), these closures are great. They keep the wines fresh and produce a higher profit for the winery based on less losses due to “Corked” wines. My problem is defining which wines I would place into which category. I tasted a 2002 Koehler Cab from Santa Ynez that a friend of mine had in his cellar. This wine was fantastic. The benefits of proper storage with a cork closure allowed enough oxygen to infuse into the wine over 7 years to produced a wine that had great color and flavor in my opinion. Based on my wine preferences, I will stick with cork. What about you?

One thought on “Rusty’s Wine 102: Wine Bottle Closures

  1. Interesting points, Rusty.

    As I think you know, I prefer drinking younger wines [wine snob vs. wineaux], so the aging issue isn't a factor for me. I am interested, however, to see how this issue will play out over the next several years as the aging factor is put to the test.

    Regarding TCA, unfortunately the twist-off doesn't entirely prevent the taint if the winery happens to be infected with TCA from things other than the corks. Still, the twist-offs are sure easy to open when all you want to do it pop-and-pour and get on with it.

    Have your read To Cork Or Not To Cork? It is in my pile of books to read one of these days.

    Also, have you ever tried the "plastic wrap" method of removing cork taint? I've heard of varying degrees of success with this.

    Michael Perlis

Comments are closed.