There are several types of cork stoppers available on the market today, with different characteristics, suitable for different products and needs. In this blog post, we explore the main types of cork stoppers on the market and what type of products they are best suited for. Find out how to choose the best cork stopper for your drink!
Summary:
- Contextualisation of cork as a closure
- Types of cork stoppers
- How to choose the right cork for your product?
- Conclusion
1. Contextualisation of cork as a closure
Cork stoppers play a fundamental role in the preservation and maturation of alcoholic beverages. As well as ensuring an airtight bottle seal, cork allows for controlled micro-oxygenation, which is essential for the development of aromas during ageing. Oxygen promotes chemical reactions between the components, leading to the formation of new aromas and the softening of tannins. In addition, there is a transfer of compounds that give the drink specific aromatic elements, which contribute to its complexity.
At the same time, micro-oxygenation allows the formation of the “bouquet”, the set of aromas that characterise the wine at hand. The “bouquet” is made up of primary aromas (from the grapes), secondary aromas (developed during fermentation and malolactic processes) and tertiary aromas (formed during ageing).
2. Types of cork stoppers
2.1. Natural cork stoppers
Manufacturers create natural cork stoppers by drilling a single piece of cork into a cylindrical or conical shape.To this day, only this type of stopper is able to provide a perfect balance in the wine’s maturation environment, allowing it to evolve correctly and forming the popular “bouquet”.
With the natural stopper, it is possible to ensure excellent wine preservation without interfering with the harmony of its elements. Besides, only its natural material is able to adapt correctly to the internal irregularities of the neck, guaranteeing a perfect seal even if the glass expands or contracts. This can happen if the ambient temperature changes during transport or storage. We can therefore expect a perfect seal over decades. It is therefore suitable for cellar wines that may be subject to a long ageing period in the producer’s cellar and an indeterminate duration until consumption by the consumer.
The most common sizes of natural stoppers are 54×24 to 26mm, 49×24 to 26mm, 45×24 to 26mm, 38×24 to 26mm, 38×22 to 26mm and 33×21 to 22mm (length x diameter).
At J.A.Beira, control and disinfection processes, such as SuperClean Plus, guarantee superior quality. We also provide individual analysis processes, stopper by stopper (B-100), guaranteeing the elimination of TCA incidents.
2.2. Natural multi-piece stoppers
Multi-piece natural cork stoppers are made from two or more pieces of natural cork glued together using a glue approved for contact with food. These thinner cork stoppers, with higher density, are crafted from cork not thick enough for one-piece natural stoppers.
Bottlers widely use these types of stoppers in large-format bottles, requiring larger stopper calibers.
2.3. Colmated natural stoppers
Colmated stoppers use natural cork with its pores filled with cork powder resulting from the grinding of natural stoppers. The purpose of colmation essentially enhances the visual appearance of the stopper and improves its performance. These are stoppers with a very homogeneous visual appearance and good mechanical characteristics, making them the ideal option for maintaining the attractiveness of wine at an economical price, using a natural cork stopper.
They come in a wide variety of shapes and the most commonly used dimensions are 49x24mm, 38x24mm, 38x22mm and 33x21mm (length x diameter).
2.4. Technical stoppers
Technical stoppers are designed for bottling wines that are generally intended to be consumed within 2 to 3 years. They consist of a dense body of agglomerated cork with 1 disc of natural cork glued to both tops or with 2 discs on one top only.
This type of stopper is chemically very stable and mechanically very resistant, proving to be an excellent seal over time. In addition, the quality of this stopper is very homogeneous and manages to maintain the necessary concentration of free SO2 in the bottle, preventing premature oxidation of the wine without, however, developing unpleasant reduction aromas.
The most commonly used sizes are 44×23.5mm and 40 or 39×23.5mm (length x diameter).
2.5. Champagne corks
As the name suggests, manufacturers specially design these stoppers to seal Champagne, sparkling wines, or sparkling wines and cider. They belong to the “family” of technical stoppers, as they are produced from a body formed from an agglomerate of cork granules, to which one, two or three discs of selected natural cork are applied on one of the tops. They have a larger diameter, which is essential to withstand the high pressures in sparkling wine bottles. To achieve the best physical and chemical performance, these stoppers go through meticulous production and strict quality control.
You can find them in the following formats: 0+2 (agglomerate body + 2 natural cork discs), 0+1 (agglomerate body + 1 natural cork disc), or simply agglomerate or microagglomerate without discs.
2.6. Agglomerated stoppers
Agglomerated cork stoppers derive entirely from cork granules that are by-products of the production of natural cork stoppers and can be produced by individual moulding or extrusion. They are an economical solution for ensuring a perfect seal for a period of no more than 24 months. Plus, they are completely homogeneous within the batch as a result of a highly industrialised process.
The most commonly used sizes are 44×23.5mm, 38×23.5mm and 33×23.5mm (length x diameter).
2.7. Microgranulated stoppers
Microgranulated stoppers are new generation stoppers with an agglomerated cork body of specific granolometry. These granules attach to each other using an adhesive approved for food contact. They undergo a procedure designed to improve their sensory neutrality. Its main characteristic is its high structural stability. Experts recommend it for wines with some complexity that consumers plan to consume quickly.
In terms of length, manufacturers typically produce them in 49mm, 44/45mm, or 38mm sizes.
2.8. Capsulated stoppers
A capsulated stopper combines a cork stopper with a top capsule made of various materials like wood, PS or PP, or metal. Consumers generally use it in liqueur/generous wines or spirits, such as Port, Whisky, Vodka, Cognac, Armagnac, Brandy, Liqueurs, and Spirits. This stopper offers great practicality for both bartenders and consumers, enabling easy reuse — a crucial factor for partially consumed bottles.
The most common calibres are: 27x20mm, 27×19.5mm, 27×18.5mm, 24x17mm and 18×13.5mm (length x diameter).
At J.A.Beira, we also have our Premium Series collection, made up of capsulated cork stoppers with a visual identity that stands out due to the materials used and the personalisation and quality associated with them. They are analysed, prepared and glued individually and validated by our Quality Control before being packed and sent to the customer.
3. How to choose the right cork for your product?
There are several factors that influence the choice of the ideal stopper.
Initially, ascertain if the product is for immediate use (e.g., table wines) or for extended, multi-use (e.g., spirits). Additionally, analyze the bottle and neck shape and size to determine the stopper caliber accurately. Another factor to consider is whether there is a long ageing period in the cellar or whether it is a wine for quick consumption.
At J.A.Beira, Quality Control department monitors the cork stopper definition process through validation tests, including dimensional, sealing, migration, and accelerated aging tests.
4. Conclusion
In summary, the cork stopper preserves alcoholic beverage quality, enhancing the cherished aroma known as the “bouquet” valued by consumers. The cork stopper industry has evolved and today there are various types of stoppers, from natural stoppers to capsulated stoppers and technical stoppers, capable of adapting to the specific needs of each drink. If you want to buy cork stoppers as a closure for your product, please contact us.