Concha y Toro

Ania Smolec 09/06/2017

Wine Corks 101

If you have doubts about which kind is better, today we want to tell you all about its types, uses and qualities.


I never throw away the corks because each one reminds me of a wine and a moment shared with my family. My collection contains real oak corks, but also different types of artificial ones. If you have doubts about which kind is better, today I want to tell you all about its types, uses and qualities.

Natural cork has several uses, but without a doubt the wine world is its biggest consumer. Its main objective is to preserve wine for long-term storage. But not all corks are the same. Natural corks, the most popular and well-known, have been used for centuries due to the elasticity of their cellular structure.

The cork is malleable to a certain extent, with the ability to contract and expand. In reality, it is almost airtight because some air is able to pass through natural cork, because microscopically there are holes inside the cork structure. This can be beneficial or harmful, depending on the type of wine that is stored. Some wines age better with exposure to air for periods of time, while others stay much better when exposed to the absence of air during storage.

Botellas livianas

Both the type and size of the cork are determined by the type of wine, the amount of pressure contained within the bottle and the diameter of the bottle neck. Today, there is a wider variety of types of wine corks and bottle stoppers to preserve wine. Some winemakers, especially those who produce great volume, are using screw caps instead of corks.

While the type of cork (or lack of it) somehow affects the taste of wine over time, as well as our perception of taste, it is also critical in protecting wines as they age. Some types of wine corks are more reliable than others. Let’s take a look at the main types of wine corks:

Natural corks

Did you know that Portugal is the largest producer of natural corks, concentrating 50% of the market? Spain ranks second with 30%. The “natural cork” is a term that covers different grades and styles of bark of a type of oak called Mediterranean cork oak.

These corks are 100% natural, and can be one-piece cut from a cork sheet, or several pieces, where at least two pieces are bonded, or agglomerated, where the small holes inside a natural cork are filled with cork dust and glue.

Corcho natural

Natural one-piece corks are ideal for long-term wine aging, as they expand and stay strong for long time periods. When removed from a wine bottle, a natural one-piece cork will expand to 85% of its original size almost instantly, while recovering the rest of its original shape within the next 24 hours.

Agglomerated corks

Agglomerated corks are composed by small pieces of natural and / or synthetic cork. They are cheaper because they are produced with natural cork bark scraps, cork dust and glue.

corcho aglomeradoAgglomerated corks work well with wines that do not need to be aged for long periods, those that are drunk for no more than two years from their harvest.

Synthetic corks

Synthetic corks have only begun to be used on a large scale within the wine industry for the last three decades. They are most commonly made from oil-based plastic, while certain synthetic cork manufacturers are also experimenting with the use of plant-based polymers of corn and sugar cane.

corcho sintéticoSynthetic corks can be advantageous for winemakers who are looking to achieve a scientific degree of oxygen transfer. These materials can be made with various densities and different materials. Over time, there seem to be more positives than negatives. Because the material used to make synthetic cork is not natural, wines will never be at risk of cork corruption.

Even for the consumer, there is some advantage of home storage, as the bottle can be kept standing, because it does not require the moisture of the wine to maintain the integrity of the cork. It is an airtight and anti-bacterial seal.

Sparkling wine corks

We all love the sound of a cork holding a bottle of sparkling wine, but with all that pressure you need a tougher stopper.

corcho espumoso

An average bottle contains more than a million bubbles and more air pressure, therefore the sparkling wine stoppers are always produced from high quality compressed cork and have an aerodynamic design that at first glance looks like a small mushroom.

Wine-Lok / Vinolok

It is one of the strangest ways to cover a bottle of wine and the most technical of all.

This cap is usually made with plastic or glass and used as an airtight seal to prevent oxygen and bacteria from affecting wine. It is a very expensive stopper and is used for refined wines.


It is a type of seal that combines “cork” with a screw cap. The cap is rotated, but when removed it produces the same sound that we associate with a cork.

It is a modern and still unpopular way of capping wines, but it combines very well the comfort and sensorial experience of the wine ritual.