Products - Cork vs. Artificial Closures

800 million cells make all the difference

Consumers prefer wines with cork stoppers. Surveys conducted in several countries confirm that at a global level, cork stoppers are the preferred choice, regardless of the segments and situations in which wine is consumed. Consumers associate cork stoppers with the quality of the wine and regard artificial closures as a factor which devalues it. However, it is no coincidence: cork stoppers are more environment friendly and contribute to the development of the wine like no other alternative.

The act of opening a bottle of wine which has been sealed with a cork stopper has a special flavour, even when we are at home. That is what several independent surveys carried out in France, Italy, Germany, the United Kingdom, Spain, and the United States confirm. And it is not just because of the celebratory sound of a cork being pulled out of a bottle. It is because consumers associate natural cork stoppers with good or fine quality wine.

In fact, it is the 800 million cells found in a single natural cork stopper that make all the difference. No other solution combines the inert nature of cork, its impermeability, flexibility, sealing capacity and resilience. Studies of the interaction of cork stoppers with wine, published in 2011 in the American Journal of Enology and Viticulture, show that natural and technical cork stoppers are ideal to seal liquid and gas. Conversely, artificial stoppers, although they seal the liquid, are unable to seal the gas. Just this detail can expose the wine to contamination by small volatile compounds present in the environment around the bottle.

With the cork stopper, the need to protect the wine from harmful particles does not prevent it from breathing. On the one hand, because cork cells are made up of an air-like gas; on the other, because the raw material which makes up the cork stopper has a natural ability to adapt to the shape of the bottleneck, which no artificial stopper is able to do. Thus, the cork stopper prevents the wine from spilling, but does not prevent it from breathing and developing. This is a vital feature, above all because oxygen is one of the most important factors in the development of bottled wine and its dissipation within the bottle relies heavily on the efficiency of the cork stopper.

«Once, a winemaker I know did a test to see how plastic stoppers affect a wine's flavour. He filled empty wine bottles with water, placed plastic stoppers in them and stored them in the cellar. After six months, the water from certain bottles tasted like a Barbie doll - and those were the best ones.»

Aldo Sohm,
Sommelier at Restaurant
Le Bernardin , New York

Artificial? No, thank you.

Scientific studies and the experience of wine producers show that there are several problems related to the use of artificial stoppers: premature oxidation, the absorption and transfer of aromas or strange flavours are some of the drawbacks most associated with synthetic stoppers. Moreover, they increase the difficulty in extracting and resealing the bottle and removing from the cork screw. In the case of screw caps, the technical limitations are becoming increasingly evident: they stimulate the development of sulphur odours in the wine and cause technical problems on the bottling line, are vulnerable to damage caused in transport and can cause post-bottling oxidation, delay the development of the wine and are not appropriate for long-term storage.

Added to all of this is still the fact that artificial stoppers may also be a source of TCA (2,4,6-trichloroanisole), a compound present in nature, which may alter the flavour of the wine and for many years was associated exclusively with cork stoppers. However, while artificial stoppers continue to debate with this and other enemies of the taste, the cork industry has invested against TCA in an exemplary fashion - in the case of Corticeira Amorim and as a result of major investment in terms of R&D, TCA levels in cork stoppers are below the detection limit.

The positive influence of cork stoppers on wine is renowned, even in countries where artificial stoppers are almost compulsory, which sometimes takes on facets which are more ideological than technical. Such is the case of New Zealand, where wine critics argue in favour of cork stoppers. In that country, some of the most distinguished wine producers choose cork, as in the most mature and traditional markets, while others, who had abandoned the cork stopper are returning, disappointed with the aluminium screw cap. Among other key examples are Sacred Hill and, in neighbouring Australia, Rusden.

«After a five year experience with aluminium caps, it has become clear that cork is best for our wines. From a technical or sustainability point of view or from an aspirational point of view on the part of the consumer, cork is wine's best ally.»

Christian Canute
Rusden, Australia

Price/quality factor

The improvement in the quality of cork, the problems associated with artificial closures and the unwavering consumer preference for cork stoppers, are increasingly the key decision-making factors for wineries to choose cork stoppers and not the so-called alternative products. In the market benchmark of the USA, a study carried out by A.C. Nielsen between 2010 and 2012 confirmed an increase of 26% in sales and 23% in revenue from wines sealed with cork stoppers - against a decline of 12% and 7% respectively, for artificial closures. According to the study, 61% of the 100 top premium wine brands use cork stoppers. The study focused on the main brands priced above 6 dollars (4 euros), which shows that the choice of cork is increasingly broader and competitive, against artificial closures.

The introduction of technical stoppers, such as Twin Top, champagne stoppers and Neutrocork stoppers, manufactured by Amorim, has broadened the range of cork stopper options, which are of excellent quality and indicated for each market segment, regardless of price. In some markets, cork stoppers such as Neutrocork may cost less than half the price of the main oil-derived closures.

Louisa Rose, Chief Winemaker of the Australian wine producer Yalumba, says although the caps have their advantages, exporting the product may be problematic. «Some of the Asian markets and particularly China are very adamant the best wine in the world is sealed under cork and if we want to be considered to be the best wine in the world ... most wineries are realising that in fact it does have to be under a cork still» 

The majority prefer cork

The USA, France, Italy and Spain are some of the countries which remain faithful to cork stoppers. The perception of quality associated with this natural closure is common to the majority of consumers surveyed.

In the USA, a study carried by Tragon, published in 2012, found that the type of closure has more influence on the purchasing decision than the type of wine, price or country of origin. An overwhelming 94% of respondents said they would be more likely to buy wine with natural cork. For a massive 93%, cork is associated with high quality wines. This perception is three times higher when compared to synthetic closures and nine times higher in regard to caps, which half the respondents associate with low or very low quality wines.

In Spain, loyalty to cork is common to a significant 92% of consumers, shown by a study carried out in 2012, within the framework of the Cork project. Results show that 86% of Spaniards believe that the cork stopper preserves the quality of wine and cava better, compared with artificial closures. In regard to perception, 27% highlight the natural factor associated with the cork stopper, 26% mention tradition, 14% refer to the possibility of recycling the cork stopper and 13% point to its quality as a closure.

Italy, which accounts for 22% of the world wine market, has shown that it is increasingly convinced that the best closure to protect the quality of the wine is the cork stopper. It is the preferred choice for 85% of consumers surveyed in 2011 by the market research company Demoskopea. For an even higher percentage, 88%, opening a bottle of wine and smelling the cork is a pleasure. In the same study, over half of those interviewed (57%) said that they were willing to pay more for a bottle of wine sealed with cork. For 97% of Italians, the cork stopper is associated with tradition, while 83% consider the protection of the environment important and 77% the quality factor. The majority (88%) also recognises it as a recyclable product.

In France, a study by Ipsos in 2010 showed that nine out of ten consumers and eight out of ten wine industry professionals also prefer cork stoppers. Among professionals (distributors, winemaking businesses, sommeliers and oenologists), 91% use cork stoppers regularly and 80% frequently. They recognise the contribution cork makes to the wine maturation process and believe that it is better at preserving all the aromas when compared with aluminium caps or plastic closures.

From the general French public, 96.3% of those interviewed associate the cork stopper with tradition, 89.8% state that cork preserves all the wine's aromas and 89.3% do not hesitate when choosing between a cork stopper and another closure. The choice is cork.

In Germany, a study developed by the University of Mannheim in 2010, within the scope of the «Natürlich Kork» campaign, showed that not only is the cork stopper the best known, but that it is the preferred choice for over half (57%) of the respondents. When buying wine, 53% are willing to pay an additional 5% or more for a wine sealed with natural cork. The degree of satisfaction in regard to the cork stopper is 69% across all respondents. Among those who usually choose natural cork, the degree of satisfaction exceeds 80%. Germans prefer cork because they believe that the wine is high quality and associate the cork stopper with sustainability and ecology.

A question of «uniqueness»

Over the past few years, Amorim has noted and supported several movements to return to the cork stopper in various key markets, such as the United Kingdom, in this case, particularly at large-scale retail level.

The United Kingdom is still a poorly informed market on the benefits of cork for wine and even on the harvesting process of the raw material. Qualitative research on the attitude and behaviour of consumers, conducted in 2010 by independent consultancy Cragg Ross Dawson, shows that some of those surveyed wrongly believe that cork results from felling trees. Yet the environmental and aspirational factor is what weighs the most in the choice of those who are better informed.

Despite the majority of those surveyed in the United Kingdom admitting that they buy, above all, fast consumption wine, they are clearly aware of the association of cork stoppers with higher quality and older wines. The choice of wines sealed with cork is shown to be more emotional, usually because it is associated with quality, the ritual of removing the cork stopper and the sound (the pop), tradition and authenticity, maturity (of both the wine and the consumers) and nature, among other factors. On the other hand, the cork stopper is also associated with more expensive wines and restaurants, which, curiously, could be a preferential factor - the respondents admitted that with other people they feel more motivated to choose bottles with a cork stopper, even if the motive may be the concern for what others think about their choice. Thus cork sealed bottles are often the preferred choice on special occasions and in a restaurant setting.

In the United Kingdom there is a large wine consumption market sealed with screw caps, but the respondents admit that they miss the «feeling of uniqueness» when they opt for this solution. In regard to plastic stoppers, English respondents are disappointed and even feel misled. It is this type of closure that they associate with poor quality wine and the opposite to the natural factor of cork. Indeed, nature and the benefits to the environment are characteristics which are more associated with cork stoppers, whether due to their production being associated with a smaller carbon footprint than artificial closures, or because they help to preserve forests. Wines with a cork stopper contribute to maintaining a sustainable industry, a heritage, a tradition and very specific lifestyles.

«Our wines really are better with cork. They may not be perfect, but simply
taste better.»

Duncan Savage,
Cape Point Vineyards, South Africa

It promotes business and a positive image

It seems simple, but it is not always so easy to opt for wines with cork stoppers. The buyer is often faced with a lack of information on the type of closure used. It is a blind test at the time of purchase. Information on the use of the cork stopper on the label of the bottle of wine has double benefits - to the consumer and to the brand, which has more chances of increasing sales. i.e. in Spain, 78% of consumers say that this indication on the label is important, due to the type of closure not always being visible outside the bottle.

In general, consumers associate screw caps with cheap wines and plastic stoppers with the notion that they are being misled. That idea is reflected in brand results. In the USA, A.C. Nielsen concluded in 2010 that the brands of wine that use cork stoppers show higher annual growth in sales and more stable prices than those which opt for the alternatives, such as aluminium caps and synthetic closures. Look at the case of the New Zealand wine, Nobilo Marlborough which in 2009 became the best-selling sauvignon blanc in the USA. Despite being produced in a country where aluminium caps rule, it adapted its packaging to focus on US consumers, sealing it with a cork stopper. This has been a key factor in sales.

In New Zealand and Australia, where artificial stoppers have been around for some time, producers are still very much connected to the use of caps, although opposing voices are starting to be heard. Ben Glaetzer, one of the most enthusiastic young Australian producers, said in regard to the top wines across the board, that «if somebody is willing to pay three or four hundred dollars, they are going to want to see a cork stopper».

The wine magazine WBM and radio ABC also recently published articles and reports alerting New Zealand winemakers to the threat the obsession with aluminium caps represents for the decrease in the value of their potential exports to China, in addition to the negative image which comes across.

The Chinese very much associate cork with the idea of added value and, although there is no market research on the matter, experts calculate that the percentage of consumers who prefer wine sealed with cork is higher than 90%. In 2011, in a project developed by Mike Convey, Director at Abbelio Wines, a Hong Kong importer and retailer, cork stoppers were the choice for 61% of respondents. The study, conducted within the scope of an MBA thesis, involved 841 wine consumers in four Chinese provinces, including Beijing and Shanghai.

More R&D, better performance

As the outcome of major investment in R&D, recent products offer an increasingly better performance, meeting producers' expectations. Therefore, it is not surprising that an increasing number of wineries are going back to cork stoppers, as was the case for example, of Rutherford, in the USA, and Cape Point and Klein Constantia, in South Africa. In this last case, the main South African winery decided to go back to using natural cork stoppers in their Perdeblokke Sauvignon Blanc, fearing that the wine would develop a sulphur taste, caused by a long period in bottles sealed with aluminium caps. At the time, Adam Mason, Klein Constantia's main winemaker, explained why he felt safer: «I never had this kind of problem while I used cork stoppers and then, after an interruption, I can see that over the past few years, their performance has improved.»

«We have gone back to using cork stoppers in quality wines. In the ten years during which we used screw caps, the quality of cork available has dramatically improved.»

Tony Bish,
Sacred Hill, New Zealand

Another example of opting for cork stoppers in South Africa is that of SPAR, one of the main national supermarket chains. In 2012, the retailer launched 27 own brands of wine with prices from 3.5 to 16 Euros, sealed with natural cork stoppers. According to the brand, the choice of cork is not only because it is believed that it combines best with their wine, but that it is also a question of sustainability. «The time has come in which closures are compared in terms of their carbon footprint. Therefore, the environmental concerns associated with the different types of closures are important for SPAR, hence our preference for natural cork stoppers», can be read in their launch brochure.

Cork stoppers are an environmental asset

In the USA and Europe, the choice for sustainable packaging is a matter of increasing importance for many consumers and retailers. In this field, no other stopper is able to compete with cork, a completely natural raw material, which is biodegradable, renewable and recyclable and requires very little energy in its manufacture - four to five times less than artificial closures.

A study conducted in 2007-2008 by PricewaterhouseCoopers analysed the life cycle of cork stoppers and assessed the possible environmental impact of three types of closure options for bottles of wine: cork stoppers, aluminium caps and plastic closures. The results were very favourable for cork stoppers: in six out of seven environmental indicators analysed, the cork stopper demonstrated that it was the most efficient, appearing in second place only in terms of water consumption.

Even without taking into account the CO2 captured by cork oak forests, greenhouse gas emissions associated with cork stoppers are 24 times lower than those recorded for aluminium closures and ten times lower than those made of plastic.

Cork stoppers are the only closure with a positive impact, not just because they have a smaller carbon footprint, but also because they contribute to capturing CO2 in the atmosphere. According to a study published in 2010 by Assolegno, the Italian association related to the forest, by consuming 15 billion bottles sealed with cork stoppers per year, it is possible to retain the pollution caused by 45,000 vehicles, i.e. an impressive 118,500 tonnes of carbon dioxide annually. If we add this data to the important role of the ecosystem of the cork oak forest in sequestrating CO2, preserving the species, combating desertification and creating jobs, there is no doubt as to the positive impact associated with the use of cork stoppers.

The cellars which use cork stoppers may reduce from between 18% to 40% of CO2 emissions from their bottles, which means that this is the best option for wine producers, distributors and retailers who aim to minimise the carbon footprint and adopt the best practices in regard to environmental performance.

Cork has made drinking wine special for hundreds of years. It is the original closure and the choice of the finest wines - 70% of the wine industry prefers cork stoppers, whether for reasons related to personal experiences, the type of wine, the production techniques or the market. Cork stoppers and wine are both products from nature and combining them is the right option. Producers who opt for cork stoppers show that their wine is superior in quality.

«We decided to change to the natural cork stopper. It is a great sealant and
the fact that it is a natural product, is one of the main reasons we came
back to cork.»

Steve Rued,
Rutherford Wine Company, USA