In 2005, the world’s most famous wine critic, Robert Parker, made a series of predictions about how the wine world would look in 2015. These were published in US magazine Food & Wine, and included some thoughts about the future of wine bottle closures: “I believe wines bottled with corks will be in the minority by 2015… Stelvin, the screwcap of choice, will become the standard for the majority of the world’s wines.”

While he was spot on with some of his other predictions, unless we see a fairly seismic change in the closures market over the next 12 months, he got this one wrong. But most of us would have, at the time, agreed with this prediction – a decade ago, cork’s days looked numbered.

And this is probably the big news in the closures market at the moment – the lack of a significant move away from natural cork. “It’s such a departure from what people thought five years ago,” says Carlos de Jesus of leading cork company Amorim.

Synthetic closure manufacturer Nomacorc has demonstrated how the closures market has changed over the period 1999–2012, the time that it has been in the market.

In 1999 cork was the dominant closure type by far, with 95% of the market (this includes technical corks such as agglomerates), with screwcaps just 3% and synthetics 2%. By 2012, significant inroads had been made by screwcaps (27%) and synthetic corks (17%), but cork still had 56% of the market, which over this period had grown from 14.1 billion to around 17.3 billion.

These figures are, of course, estimates, and from one particular company. It’s almost impossible to get exact figures. For full-size (75cl) bottles, the market is thought to be around 18-20 billion worldwide each year, a figure that most closure companies seem to agree on.

What seems clear is that while screwcap sales are still growing, cork has consolidated its position, in large part led by the new generation of technical closures. New technologies for cleaning cork fragments, granules and discs to reduce taint levels has resulted in better-performing technical corks.

A particular success has been Diam, a microagglomerate cork that is taint-free and which is now being used by some Burgundy producers to seal Grand Cru wines – a significant vote of confidence.

Amorim’s De Jesus says that this year, as the largest cork manufacturer by far, it will make 4 billion closures.

Anne Seznec of Guala, the largest of the screwcap manufacturers with around 35% of the market, says screwcap sales are now 4.5 billion annually, with growth over the past year of 400-500 million.

Growth for screwcaps is mainly in Europe (which has traditionally been cork dominated), the US (where screwcaps have been unpopular for image reasons) and Argentina. Seznec reports big growth in eastern European countries and markets such as France and Germany.

So if cork sales are growing, and screwcap sales are growing, and the overall wine market is static, who is losing out? It has to be synthetic corks. “It’s now increasingly a two-way race instead of a three-way,” says De Jesus. “There’s a solid entrenching of positions, with a stable market share for corks and screwcaps ahead of synthetics.”

Yet the leading synthetic closure manufacturer, Nomacorc, reports sales of 2 billion annually, and that these numbers are growing. It must therefore be poor-quality synthetic closures that are taking the hit. This brings us on to the topic of innovation, something that all closure companies are busy doing in a bid to gain or protect market share.

Nomacorc has been one of the most innovative of all closure manufacturers. A while back it initiated a multinational research project on the interaction of oxygen with wine, in collaboration with major wine science institutions in a number of countries. This research was intended to provide a theoretical background for its current range of closures, the Select Series, which offers a range of different oxygen transmission levels.

Oxygen transmission

Oxygen transmission (known as OTR) is an important but rather geekily technical concept for wine bottle closures, and it needs a little unpacking.

In basic terms, a closure has to keep wine in the bottle, and keep air (along with it, the reactive gas oxygen) out. But if the closure keeps out all the oxygen – that is, it is a hermetic seal – then this can cause problems.

What happens is that the lack of oxygen can result in some unwanted chemistry taking place with regard to a group of smelly chemicals called volatile sulfur compounds, including the likes of sulfides, disulfides and mercaptans (aka thiols). But, while a little oxygen is helpful, too much causes oxidation. And the precise amount of oxygen that enters the bottle will affect how that wine develops after bottling. To make this all a little more complex, different wines respond differently to post-bottling oxygen exposure.

Nomacorc has a software tool called the NomaSelector which allows winemakers to match the right Nomacorc closure to their wine by answering a series of questions. The increased knowledge of the role of oxygen in the development of different wine styles provided by the research project allows winemakers to use closure oxygen transmission level as an extra step in winemaking. And they have demonstrated the difference that varying levels of closure oxygen transmission can have on a wine in a series of comparative tastings of the same sealed with different closures.

Other companies are also offering closures with specific oxygen transmission (OTR) levels. For example, Diam offers its range in three different transmission levels, medium, low and very low.

For a long time, there were only two screwcap liners for wine – Saranex (low OTR) and Tin/Saran (extremely low OTR). But this year Amcor, the second largest screwcap manufacturer, announced the release of five liners designed to offer a range of OTRs to winemakers.

California giant winery Gallo’s technical arm is also at the development stage with a series of new liners which it is likely to release in 2014. While many winemakers are perfectly happy with the existing liners (for example, New Zealand wine is 95% screwcap-sealed, using almost exclusively the very low OTR Tin/Saran liner), the existence of screwcap liners with different OTRs will be an attractive prospect for those who like the convenience of screwcaps but who in the past were worried by the extremely low OTRs of the Tin/Saran liner, which carries with it attendant risks of unwanted ‘reductive’ characters developing after bottling.

But there is more to closures than just technical performance. “We know about each of the closures and how good they are,” says Amorim’s de Jesus. “But which closures can add something on top of that basic function? The packaging becomes fundamental, and cork adds value in a quantifiable way – and this is important if you are running a winery, because you have to sell wine. This is what underscores cork’s market share.”

One area where cork has a strong advantage is in sustainability. While other closure types may be recyclable, they don’t have the same natural image that cork does. There is a disconnect in the minds of consumers when sustainability is linked with products that are plastic or aluminium.

This is where Nomacorc’s latest innovation is so clever. This is the Select Bio closures, which are the Select Series closures made using renewable, plant-based materials alongside conventional ones, resulting in a closure with a zero carbon footprint. This closure will cost a little more than the regular Select Series, and will be rolled out commercially in 2014.

Innovations

Other innovations? Guala has two screwcaps in its line-up that are designed for use with sparkling wines. While it might take a while for customers to get used to fizz sealed with a screwcap, these are already in use in Australia.

“Now we have to find another country where these fit,” says Guala’s Seznec. “Eastern Europe is more likely than France because there are so many rules surrounding sparkling wine.”

These rules have been a problem for Zork, a company with an innovative sparkling wine closure that is resealable, unlike conventional sparkling wine corks.

The Zork is an interesting closure though, and has already appeared on wines listed by Tesco in the UK.

Finally, in 2014 we’ll see the first bottles sealed with Helix, a new cork closure/bottle combination from Amorim that does away with the need for a corkscrew. This was launched with a fanfare last June, and the Helix was the third most shared story on the BBC news site on the launch day. Twelve wineries are working on it at the moment, testing it in real winery conditions.

So, the demise of cork is taking longer than Robert Parker predicted. Will we still see bits of tree bark in the necks of wine bottles come 2025? Or will the closure market look similar to the one we see today?

Whatever happens, it looks like there’s some stability now in the closure market, and that any changes are going to be slow and gradual, rather than revolutionary.