Introduction
For centuries, the cork has been “the” way wine bottles were sealed. The sound of the cork popping out of the bottle became a time honored tradition and usually represented the beginning of the festivities. Whether you were spending the evening with that special someone, or with good friends, the sound of that “pop” was akin to the starters pistol at a track meet.
Recently, however, as winemakers around the world have continued to hone their craft, they began to investigate the impact corks have on wine. Why? Well, to a certain extent, the growing, making and storing of wine in barrels has been all but perfected. And, negative effects of corks were beginning to be noticed by Sommeliers and consumers of wine upon opening up the bottle. The result of these investigations is that dozens, if not hundreds of wineries producing wines of high quality, and often high prices, have shifted towards using screw tops to seal the bottles.
History of Use
- Cork- Harvested from the Cork Oak tree, the material was found to be impermeable, buoyant, elastic, and fire resistant. While cork is used in a variety of products, the most common use is for wine stoppers. Its first record of use can be found in ancient Egypt. Throughout the years, cork was used in many different applications; fishing buoys, beehives, sandals and as stoppers for vessels of wine and olive oil. However, as late as the mid-17th century, European vintners preferred not to use cork stoppers. Instead, olive oil-soaked rags or hemp were wrapped around conical stoppers and stuffed into the necks of bottles. French Benedictine Monk, Dom Perignon, is credited with causing the widespread use of corks in wine bottles. Today, natural cork stoppers are used to seal about 80% of the 20 billion bottles of wine produced each year. It is unclear when synthetic corks arrived on the scene, but when they did there was a sharp decrease in the use of natural cork stoppers. However, notable problems arose with synthetic corks and thus, cork wine-stoppers have been making a comeback and currently represent about 60% of wine-stoppers in use today.
- Screw Cap- The screw cap, or Stelvin as it has come to be called, was developed in the late 1960s and early 1970s. It was developed by the French company La Bouchage Mecanique. Its genesis is the result of its predecessor, the Stelcap/cork combination. This closure utilized a cork and Stelcap (metal-based cap placed on top of the cork). Another form of the Stelcap was a long-skirted screw cap. The Stelcap had a different inner lining than today’s Stelvin cap (paper over cork, instead of PVDC or PVDC covered by foil-covered paper, respectively). Original trial use occurred in 1970/71 by the Swiss wine company producing Chasselas. (This wine was found to be particularly affected by cork taint.) Stelvins were first used commercially, in Europe, in 1972 by the Swiss winery Hammel. The caps were adopted commercially in Australia in late 1976/early 1977.
Advantages of each
- Cork – Cork has the benefit of a long history; it has been used as a sealing mechanism for millennia. Cork is also a renewable resource as the oak trees are not killed when the bark is stripped to make cork and they’re biodegradable. Cork stoppers also support an entire industry of corkscrews and other cork-removal products. Lastly, but maybe most importantly, the cork has the wonderful ability to let wines breathe and age inside the bottle.
- Screw Cap – Similar to synthetic corks, Stelvins allow vintners to avoid problems of cork taint. Stelvins are also less expensive than natural or plastic corks. They can also be removed without any special equipment; just a simple twist.
Disadvantages of each
- Corks – Wine Corks can often go bad. Industry estimates vary, but as little as 1% to as much as 20% of all wine sold are “corked.” This means that 1-20% of wines are damaged by a bad cork. The cork can break down releasing chemicals into the wine. Wine corks, at times, can be difficult to remove, and as most of us have experienced, can sometimes break off into the bottle.
- Screw Cap – Similar to plastic corks, Stelvins can cause environmental issues, such as difficulty with recycling the material. Stelvins also pose a threat to the cork farming industry and its associated industries (i.e. corkscrews). Stelvins also get a bad rap because screw caps are often seen as a cheap alternative destined only for the low grade wines and/or low grade liquors in brown paper bags. Lastly, the verdict is still out on how screw caps will react to long periods of aging.
As you can see, corks and screw caps both have their pros and cons. This has led to much debate over which one is truly better. Romantics love the cork, but some folks in the wine industry view screw caps as the future.
Industry Trends
Initially, screw caps were met with much customer resistance when they were introduced in Australia and New Zealand. They were actually phased out of those countries wine industries in the early 1980s, only to be reintroduced gradually in the 1990s. Since then an ever-increasing number of vintners have begun to use the screw cap within Australia and New Zealand. In New Zealand, the use of screw caps went from 1% in 2001 to 70% in 2004.
In Europe, screw caps have been met with varying degrees of acceptance. The United Kingdom has seen the acceptance of screw caps by consumers more than double from 41% in 2003 to 85% in 2011. As mentioned above, screw caps have been widely accepted since the 1980s by Swiss winemakers. In France, screw caps have also found acceptance with some vintners. Most notably, Domaine Laroche in Chablis, France has been bottling their Chablis, Premier crus and Grand Crus, with screw caps since 2001.
Screw caps were met with much resistance in Spain. In fact, Spain has passed a law that requires wineries in their 11 top wine producing regions to seal their wines with cork. In order to receive DO (Denominacion de Origen) status in those regions, wineries must use a natral cork closure on still and sparkling wines. The use of synthetic closures has also been outlawed to some degree.
In the United States, Corbett Canyon became the first million plus case brand to switch to screw caps for their entire production in 2004. Other US wineries have also made the move to screw caps. Most often mentioned is Plump Jack Winery in California.
But What about Plastic Corks?
Synthetic corks have a shaky track record. One glaring issue is their inability to prevent high levels of oxidation for any real length of time. This significantly decreases the shelf life of a wine and short-changes the maturing process of select wines. The main issue is that over time the plastic may not retain its elasticity well. Also, if not recycled, plastic corks pose a direct threat to the environment.