Why is the champagne cork shaped like a mushroom?
It's a question everyone asks, and the answer is purely mechanical.
Before being bottled, the champagne cork has a perfectly cylindrical shape, like any still wine cork. Its initial diameter is 31 mm, or 13 mm more than the internal diameter of the neck of a champagne bottle. This is deliberate: the difference ensures a perfect seal once the cork has been compressed and pressed into the neck.
The bottling machine compresses the cork and pushes it halfway into the neck. Under the effect of the bottle's internal pressure (around 6 bar, or three times the pressure of a car tire), the lower part of the cork gradually expands, a process known as "skirting". The cork then takes on its characteristic mushroom shape. The older the bottle, the more pronounced the skirting...
Why is the champagne cork made of cork?
Cork is an exceptional natural material for sealing sparkling wines. It is at once compressible, elastic and hermetic, three essential qualities for retaining bubbles under pressure while allowing the wine to evolve properly in the bottle.
The cork oak that supplies the raw material grows very slowly. The Syndicat des Bouchonniers de Champagne specifies that it is only after 35 to 40 years that the bark is suitable for the manufacture of quality corks. It's no coincidence that cork has been the absolute reference in Champagne for centuries.
The cork is made up of two distinct parts:
- The natural cork discs at the base of the cork, in direct contact with the wine.
- The agglomerated handle, which forms the body of the cork and holds it in place.
Before being inserted, the corks are softened so that they can be compressed without tearing. Once in place, they ensure a perfect seal.
Are there alternatives to cork?
Yes, but they are very rare in Champagne. The appellation is attached to cork, which is part of the very identity of the bottle. Occasionally, screw caps or synthetic corks are used on a few experimental cuvées, but these remain the exception. The cork stopper is not technically compulsory according to the specifications, but it is almost universal in practice.
What is the name of each corking element?
The champagne bottle is closed by a three-part corking system:
- The cork: made of cork, mushroom-shaped once in place. It's the central part, in direct contact with the wine.
- The muzzle: the twisted wire cage that holds the cork in place and prevents it from popping out under pressure. Its name comes from the French word for "muzzle", and this is exactly what it does. It consists of a lower ring, four metal legs and a circular plate.
- The muzzle plate: the small metal washer that caps the cork and distributes the pressure exerted by the muzzle. It often bears the logo or emblem of the champagne house. Wirehood plates are highly sought-after collectors' items, known as champagne capsules or wirehood plates, and some collectors own thousands of them.
How to store champagne after opening?
Once a bottle has been opened, it's a race against time to keep the bubbles. Here's what really works. We've also included a complete guide to champagne preservation.
A special champagne stopper is the most effective solution. They come in a range of materials:
- Stainless steel stopper: sturdy, hermetic, reusable. Very effective for maintaining pressure.
- Silicone stopper: flexible, fits most bottlenecks, good seal.
- Lever-action cap: practical to use, holds pressure well thanks to its locking system.
With a good airtight cap, an opened bottle can be stored in the refrigerator for 24 to 48 hours, retaining its correct effervescence. After that, the bubbles inevitably fade.
A few additional tips:
- Always keep the bottle upright once opened, to limit the contact surface between the champagne and the air.
- Never put back the original cork, as its mushroom shape will not ensure a hermetic seal.
- The spoon in the neck? It's a myth: it doesn't preserve the bubbles any better than a bottle that's simply been resealed.
For unopened bottles, it's the other way round: keep them lying down, so that the cork stays moist and doesn't dry out. A dry cork allows gases to pass through and effervescence to be lost.
And if you're wondering why you put a coin in a champagne cork: it's a tradition that turns the cork into a talisman supposed to bring luck and prosperity.
Alcohol abuse is dangerous for your health. Drink in moderation.
