Has it ever happened to you, looking at the wine-lined shelves of wine boutiques or supermarkets, to succumb to an involuntary temptation and suspect some kind of “conspiracy theory” emanating from the entire world wine-making community? And it’s not about the endless variety of wine styles, but about the corks with which these wines are corked.

Ordinary natural, screw, synthetic and even glass – what is their hidden meaning when your task is extremely simple: to buy a worthy wine for the upcoming celebration, without soiling the “honor of the uniform” in front of the guests? Or, strictly based on the golden rule of value for money, choose a bottle of red or white for your everyday dinner. How to recognize wines by their corks? And what is their secret essence?

Some statistics

In order to take a closer look at the rapidly changing “cork situation” of the wine market in recent years, let us turn to statistics. Today in the world, about 20% of table wines are corked with screw caps. The popularity of plastic plugs has also increased. Currently, they make up 10% of the market, and, according to experts, in the near future their number will increase to 25%. Glass corks have also become incredibly popular with manufacturers in Austria, Germany and Italy in recent years. Meanwhile, according to some estimates, natural cork has lost about 40% of the wine market since the late 1980s. This loss is most evident for wines under € 10. Be that as it may, now it is difficult to imagine that back in 2000, 95% of all wines were corked with corks made of natural material. What is the reason for this situation?


Issue price

The answer to the question of how profitable is the use of natural corks, not least of all in their cost. The price of a quality solid cork can range from forty cents to three euros. The latter, the most expensive, are naturally used for corking super-premium wines, the price status of which can reach several thousand euros per bottle. Therefore, such a sacrifice for these outstanding wines will be quite legitimate and rewarding. However, when buying a young “commercial” wine, it is not very prudent to pay a couple more euros for the cork. In other words, the winemaker chooses the cork depending on the quality of the wine. He leaves the best corks for the best wines that deserve a long aging. And everyday wines or wines with a short shelf life (especially if their creation cost him “a pretty penny”) he will “plug” with such a cork, which will clearly indicate that this bottle needs to be uncorked at the earliest opportunity. And further. If the bottle with natural cork is transported or stored for a long time in an upright (!) position – for example, after standing for a long time on a wine shelf in a supermarket – it invariably dries up, and the wine gradually deteriorates. That is why natural cork is, unfortunately, not a very suitable option for such “unclaimed” wines. And this already directly affects our unjustified hopes and, of course, wallets.

Because of the defect!

However, if the use of natural cork comes up against money, there is another explanation. One of the flaws in natural corking is the often crippling cork defect. For this reason, the volume of spoiled wine (of the total volume of wine in the world) reaches, according to various estimates, from 3 to 8%. The fact is that the cork bark contains trichloroanisole, a substance that can give wine a characteristic moldy smell. According to various estimates, every year wine estates lose huge sums due to this cork defect. Therefore, it is not surprising that, for example, the owner of the renowned company Domaine Laroche (Chablis, France) Michel Laroche in one of his interviews was very categorical: “Cork defect” ruins the best wine of our economy. At the same time, I do not see any significant differences between wines closed with different types of corks ”. Perhaps this is another reason for wine lovers, as impartially and with understanding as possible, to treat the newfangled wine “plugs” with which “everyday” wines are sealed.

Types of corks


The advantages of natural cork, the most valuable of all *, are not only traditional and somewhat ritualistic. First of all, it equips the wine in the bottle with the microscopic effect of oxygen, which allows the drink to develop and ripen calmly over the course of several decades. At the same time, natural cork protects the wine from intense contact with air, preventing it from oxidizing. That is why its use is so important for outstanding wines with great aging potential, for which oxygen in moderate doses can be the best friend, and in exorbitant doses – a mortal enemy. High-quality natural corks used to seal collection wines are always longer than ordinary corks (45 to 54 millimeters), as well as more flexible and durable, able to withstand time. Wine corks designed for short storage (5–7 years) also have their own quality standard. They are usually sealed with very flexible but not too strong corks.

By the way…

In skilled hands, natural corks break for only two reasons: when their elasticity is lost over time and they become more fragile, and also because of questionable quality.

* It is made from the bark of two types of oak: cork (Quercus suber) and western (Quercus occidentalis), now cultivated, since their natural resource has been greatly depleted. The growing area of ​​these oaks covers the Mediterranean coast of countries such as Portugal, Algeria, Morocco, Tunisia, Spain and Italy. Cork oak can also be found in France, the USA and Japan. Cork oak has a unique ability to completely regenerate the bark after 9 years after it is removed from the trunk and large branches of the tree. It is noteworthy that the older the oak, the more cork it gives (more precisely, the bark for its production). Although the average lifespan of cork oak is 170 years on average, the Montijo region, located in the southeast of Lisbon, has a 200-year-old long-lived oak, from which about 1,200 kilograms of bark are removed each time.


In addition to natural cork, there are a number of less valuable corks made from cork chips.

Colmated corks

If defects are found on the cork, it can be sent for colmatage (from the French word colmatage – “filling of cavities”). In this process, all voids are filled with fine cork chips mixed with a special glue. Colmated cork stoppers are quite presentable in appearance, but not suitable for long-term storage of wine. Another disadvantage: they often break when uncorked.


These corks are made from cork oak bark pellets left over from the production of natural corks. They are mixed with food grade glue.


They are made from pressed cork chips and a solid cork washer. Combined corks are used for wines with a shelf life not exceeding one year.


Relatively new technology. Such a cork is made under pressure from selected crustal granules no more than 0.5 mm in size, and an organic waxy substance (suberin) is added to the food glue from a cork oak. These corks, in comparison with agglomerated ones, are more resilient and elastic.

Such different plugs …

Synthetic corks

They are of two types: polyethylene (different in quality, do not allow moisture to pass through, do not deform the aroma of wine and can be easily removed from the bottle with a corkscrew) and, the most preferred, silicone. However, it is still not clear whether phenol and tannins will corrode polyethylene and whether polyethylene will decompose sulfurous acid, which can lead to rapid oxidation of wine. The question is open.

Screw plugs

They are made of an aluminum alloy with a synthetic gasket. The main advantage of screw plugs is the low price and the absolute absence of the risk of “cork disease”. The downside is insufficient mechanical strength. But, in spite of everything, the screw cap is preferred not only by table wine producers, but also by many eminent wine-making estates. However, here it should be noted that the choice of cork is not always the responsibility of the winemakers themselves. The reason for this is the legislation governing the entire process of wine production, including its capping. For example, the famous wine company Allegrini from the Veneto region (Italy) was forced to recall the batch of Valpolicella Classico, which was closed with screw caps, due to the fact that this would violate the Italian wine DOC (names of controlled origin) law. Since it was impossible to pour the wine into other bottles with the “correct” closure, the company had to solve this problem by re-sticking the labels, indicating Valpolicella without the word Classico. As a result, not only did the status of the wine suffer, but its price was significantly reduced.

Glass corks

This is the most aesthetic and attractive alternative to natural corks. However, there are some “buts” here as well. First, they are expensive. In addition, wine in a bottle with a glass cork does not develop as intensively as with a natural one. In addition, a glass stopper is a good solution for young wines, but not for wines intended for long aging. Nevertheless, today it is readily used in the New World and increasingly in the Old. In the Old World, glass corks are most widely used so far in Germany, in the northern regions of Italy and in Austria.

And the secret will be revealed

The authenticity of the wine can be established by comparing the inscriptions on the cork and the label. They must match. If a discrepancy is found, it is logical to trust the traffic jam. Why? The answer is obvious. It’s easy to re-stick the label,

while replacing the plug is practically impossible (this requires special equipment). Information applied to the cork may include not only drawings (at the request of the customer), but also an indication of the vineyard (appellation), the name of the place where the wine was produced, the year of the harvest (as a rule, it is indicated on the end part of the cork, which professionals call a mirror), as well as where the bottling took place, that is, the bottling of wine, etc. In the countries of the European Community, these inscriptions are not mandatory. With one exception: on the corks of sparkling wines, in order to avoid forgeries, the name of the appellation corresponding to the wine is always indicated. For example, Champagne, Crémant de Bourgogne, Cava, Franciacorta.