The Screwcaps are coming! The Screwcaps are here!!

When you think about it, corks are strange. No one knows who originally thought of cutting the bark from the Quercus Suber tree into some kind of cylinder shape and then hammering the result into the neck of the bottle. Maybe it was the inventor of the corkscrew, an equally strange contraption! Corks are used to keep the wine in the bottle and the air outside the bottle. People have devised a number of other ways over the years to keep things in bottles, but corks are traditional for wine bottles.

There are, however, two problems with corks. First, a very small percentage of them leak (maybe 1 in every 100) allowing oxygen to come in contact with the wine. This spoils the wine by causing it to oxidize. Second, even without leaking, corks can affect the taste of the wine. They can cause the wine to be “corked.” (Not wines which have small pieces of cork floating in the glass when you pour them out. That’s just a badly pulled or a very old cork!). A corked wine is one where a chemical called TCA suppresses the fruit flavor and taints the wine. A corked wine smells musty and vegetal, and there is a similar taste. And a wine can be tainted to different degrees. It can be slightly tainted such that some people wouldn’t pick it up on the taste, or it can be so disgusting that anyone would reject it! Some estimates put the number of bottles affected by cork taint as high as 10%. That’s definitely an overstatement, but even a more realistic 2% is unacceptable.

There have been some developments in the realm of wine closures to eliminate the problem of corked wines. By now I’m sure you have seen the synthetic corks that are used in many moderately priced California and Australian wines. A few wineries have tried the crown cap, like the top on a beer bottle. But hold on to your Riedel glass. In the next 12 months you will begin to see a flood (well, perhaps a serious trickle) of higher quality wines sealed with a screw cap!

So far, several high profile wineries have begun producing wines with screw caps. The most famous is Plump Jack, a Napa Valley cult winery that bottles fully half of their Cabernet Reserve with screw caps. The experiment, to compare the aging of screw-capped versus cork-enclosed wine, will take many more years to complete.

Kim Crawford, the highly regarded New Zealand wine maker, will be releasing his 2001 wines with screw caps this fall. Oregon’s WillaKenzie recently announced that 15% of their production will be in screw cap bottles.

The charge toward screwcaps is being led by New Zealand. By 1999 the incidence of cork taint had became a serious concern to many members of the wine industry. Alternative closures had by that stage led to the evolution of the composite, plastic (synthetic) cork, and to the cork with a plastic seal. Various methods of sanitizing corks were also under close scrutiny.

In 2000 an informal meeting was held in Marlborough to discuss the problem, and from that grew an initiative to evaluate the various alternatives to the traditional cork closure. After some research the concept of the screwcap wine seal was raised for closer evaluation and technical overview. The screwcap wine seal was not an original concept. For over thirty years some wines had been sealed using a screwcap closure – for the most part low cost wines, which gave rise to a perception of the screwcap being a ‘cheap’ alternative, and this led to consumer resistance. Those in the know, however, had long recognized the superior quality of wines sealed in this manner, and ‘library wines’ bottled privately by many wineries for long-term storage used this type of closure.

Technical evidence in support of the screwcap closure was presented in an Australian Wine Research Institute (AWRI) Report, which published the results of trials carried out on a range of bottle closures. The publication of this result (http://www.awri.com.au) stimulated further debate regarding the performance of various wine closure types.

The New Zealand Screwcap Wine Seal Initiative
In May 2001 the ‘New Zealand Screwcap Wine Seal Initiative’ was born. The initiative now has 29 members, representing top wine producers from Auckland, Hawkes Bay, Martinborough, Nelson, Marlborough, Canterbury, and Central Otago. The group has enjoyed great support from the Clare Valley Wineries of Australia who shared their experiences following the introduction of their own premium Riesling wines sealed under screwcap.

The exciting culmination of all this work has been the release of a number of premium New Zealand wines for the 2001 vintage under screwcap. These wines will represent every wine producing region in the country, several wine varieties (including Pinot Noir and Merlot), and over twenty producers. The move to screwcaps is being led by some of New Zealand’s top winemakers. The sole motivation for the move is to improve quality, and this has been succinctly expressed by Michael Brajkovich MW of Kumeu River Wines. Michael was asked why he would even consider using the lowly screwcap for his wines, and his reply was, “Because it will make my wines better.”

The following New Zealand wineries are members of the New Zealand Screwcap Wine Seal Initiative. Not all are currently bottling with screwcaps, but many of them are.