Screw cap (wine)
A screw cap is a metal cap that screws onto threads on the neck of a bottle, generally with a metal skirt down the neck to resemble the traditional wine capsule ("foil"). A layer of plastic (often PVDC), cork, rubber, or other soft material is used as wad to make a seal with the mouth of the bottle. Its use as an alternative wine closure is gaining increasing support as an alternative to cork for sealing wine bottles. In markets such as Australia and New Zealand screw caps on bottles have overtaken cork to become the most common means of sealing bottles, right across the wine industry.
Benefits and concerns
Compared to cork, screw caps reduce the wine faults of oxidation and of cork taint, although it is possible to find TCA contamination in a screw cap bottle.  Screw caps are generally perceived as easier to open. Screw caps have a much lower failure rate than cork, and in theory will allow a wine to reach the customer in perfect condition, with a minimum of bottle variation. Cork, of course, has a centuries-old tradition behind it, and there are also concerns about the impact of screw caps on the aging of those few wines that require decades to be at their best. Some argue that the slow ingress of oxygen plays a vital role in aging a wine, while others argue that this amount is almost zero in a sound cork and that any admitted oxygen is harmful.
The converse of oxidation is reduction, and it has been suggested that screwcapped wine leads to reductive characteristics. These include a sulfur smell which in some circumstances adds a pleasant pungency to the wine, or may be distasteful.
Stelvin screw caps
The most known brand of wine screw caps is Stelvin, a brand developed by Rio Tinto Alcan, and now owned by Amcor. The brand name has genericized in common use, with many in the wine trade referring to screw caps as "Stelvin closures", regardless of brand.
The distinguishing features of wine screw caps, in particular Stelvin brand ones, are:
- a long outside skirt, for aesthetics: to resemble the traditional wine capsule ("foil")
- the use of the plastic PVDC (Polyvinylidene chloride) as a neutral liner on the inside wadding
The Stelvin was developed in the late 1960s and early 1970s, and commercialized in the 1970s. It was developed by French company La Bouchage Mecanique, thence acquired by Pea-Pechiney, which became part of Alcan, then Rio Tinto Alcan and now Amcor. It was developed at the 1964 behest of Peter Wall, Production Director of the Australian Yalumba winery, working with other companies. It was preceded as a closure by a Stelcap/cork combination (closed with cork, with a Stelcap on top): the Stelcap was also a long-skirted screw cap, but with a different inner lining (paper over cork, instead of PVDC or PVDC covered by foil-covered paper in a Stelvin).
It was originally trialled in 1970/71 with the Swiss wine Chasselas, which was particularly affected by cork taint, and first used commercially in 1972 for the Swiss winery Hammel. It was adopted commercially in Australia in late 1976/early 1977. For noble wines, wines from the 1971/72 vintage (such as Haut-Brion) were sealed with Stelvin, then tasted in 1978, and found similar to cork-closed wines.
In 2005, a modified Stelvin cap, Stelvin Lux, was introduced. Like the standard Stelvin cap, the outer shell is aluminium, but there is no externally visible screw thread or knurling, giving the closure a cleaner look more like a traditional foil capsule. Internally, there is a pre-formed thread, and the sealing materials are the same as the standard Stelvin cap.
In the UK, acceptance by consumers more than doubled, from 41% in 2003 to 85% in 2011.
Screw caps were widely adopted in the 1980s by Swiss winemakers, and have shown increasingly wide adoption in the succeeding years.
Screw caps met with customer resistance in Australia and New Zealand, and were phased out in the early 1980s, only to be reintroduced gradually in the 1990s. Since reintroduction, ever-increasing numbers of winemakers are using the screw cap within Australia and New Zealand. In New Zealand, adoption went from 1% in 2001 to 70% in 2004.[dated info] Screw cap adoption in fine wines in Australia has proceeded in fits and starts. In July 2000, a group of Clare Valley Riesling producers, led by Jeffrey Grosset bottled a portion of their wines in screw cap, and earlier that year PlumpJack Winery announced it would bottle half its production of US$130 1997 Reserve Cabernet Sauvignon in screwcap. Other announcements have followed, including one from Bonny Doon Vineyard in July 2002 that 80,000 cases of its "Big House" red and white wine would be bottled under screwcaps - followed by almost all the rest of its production by late 2004 (200,000 cases total).
In July 2004 Corbett Canyon became the first US million plus case brand to switch to screw caps for its entire production, shipping just over three million cases a year.
Some appellations ban the use of screw caps, including (as of June 2013[update], Valpolicella Classico); in 2008, the ban led Italian producer Allegrini to withdraw from the Valpolicella Classico denomination in order to use a screw cap.
- Speedy, Blair (November 13, 2010). "Screwcaps give better sense of closure". The Australian. Retrieved 2013-06-17.
- Mobley, Esther. "Is it possible to find TCA contamination in a screw cap bottle?". WineSpectator. WineSpectator.
- "How to remove a screwcap". blogspot.com. November 29, 2011. Retrieved 2013-06-17.
- Moore, Victoria (2011-03-31). "Wine review: Cork vs cap". The Daily Telegraph (London).
- Courtney, Sue (13 August 2001). "The History and Revival of Screwcaps". Wine of the Week.
- Amcor Closure Systems Pty Ltd
- Woodard, Richard (November 14, 2011). "Screwcap now "the norm": new study". Decanter. Retrieved 2013-06-17.
- "Grosset & Gaia - James Halliday's Wine Companion". Winecompanion.com.au. 2007-10-13. Retrieved 2010-10-23.
- "Screwing around with caps". Napa Valley Register. October 12, 2007. Retrieved 2013-06-17.
- "The Search for the Perfect Seal". Nicks.com.au. Retrieved 2013-06-17.
- "Bringing closure? A screwcap-cork showdown". Dr Vino. March 26, 2007. Retrieved 2013-06-17.
- "Largest wine producer in the US adopts screw tops". Food Production Daily. Retrieved 2013-06-17.
- de Castella, Tom (16 June 2013). "Why the snobbery over corks?". BBC News Magazine (BBC). Retrieved 2013-06-17.