Why Are Champagne Corks Made Out of Natural Cork?


There’s just something about natural cork. Newer technology may have its devotees, but there’s a good reason why good, old-fashioned cork is used to seal champagne bottles. Even if you set aside years of tradition and the satisfying “pop” you just can’t get with any other material, there are still plenty of benefits to traditional cork over synthetic materials and screw tops.

How It’s Made

Cork actually comes from the bark of the cork tree, which grows primarily in the montado forests of Portugal. Responsible harvesting makes cork a renewable resource, and small teams typically harvest the bark, allowing the trees to survive and the bark to regrow. The cork bark can usually be be harvested again every nine years.

Once harvested, the cork bark is cured, graded, sorted and then processed into natural cork disks and rods of agglomerate cork. The rods are sliced into the individual corks used to seal champagne bottles, with a natural cork disk affixed to each end.

The Natural Cork Difference

The key characteristic of natural cork that makes it perfect for sealing champagne bottles is its ability to expand. Pressure beverages like champagne – along with sparkling wines, ciders and some beers – are bottled at great pressure, and they require a seal that can prevent the escape of gases while at the same time maintaining the perfect gas pressure within the bottle. That’s where natural cork comes in.

When compressed, natural cork expands. The typical cork used to seal a champagne bottle has a diameter of 31 millimeters, but is compressed down to a diameter of 18 millimeters to fit into the bottle neck. Once in place, the cork naturally continues to expand, which allows it to keep constant pressure against the glass bottle neck. This pressure keeps gas from escaping, and makes natural cork the perfect stopper material for a champagne bottle.

That Tell-Tale Shape

You can tell a natural cork has done its job by its shape when you remove it from the bottle. You’ve probably noticed that corks come out of a champagne bottle with a recognizable mushroom shape, but they don’t go in that way. Corks are straight when they are inserted into the neck. The mushroom shape is the result of the lower half of the cork being compressed into the bottle neck, while the upper half continues to expand.

The Trouble With Synthetic Corks

Unlike natural cork, synthetic corks do not expand. They maintain a rigid shape, which can mean a loose fit and imperfect seal in some bottles. Ill-fitting corks can ruin a bottle of perfectly good wine or champagne.

Natural corks are also difficult to remove without a corkscrew, whereas natural corks are designed to be removed from a champagne bottle by hand. Just remember to never point the bottle at yourself or anybody else while you open it. Champagne bottles stopped with natural cork tend to open with a powerful “pop,” sometimes sending the cork flying. It’s a small price to pay for a perfect seal!

What Does Bubble Size Say About A Champagne?


Drinking champagne is as much a cultural phenomenon as a culinary one. We celebrate grand openings, graduations and marriages by popping the cork on a quality champagne, and we also enjoy a creamy brut champagne paired with our favorite appetizer perhaps almost as much as the overarching occasion.

Bubbles in Champagne 

Often colloquially referred to as “bubbly,” the bubbles in champagne actually have a lot to do with the popularity of, say, a brut over a doux champagne.


Although today we can dine over a Krug or Laurent-Perrier brut without worrying about much of anything, this wasn’t always the case.

Champagne was once called the devil’s wine because of its propensity to spontaneously explode – sometime causing a chain reaction in fermenting cellars.

In fact, the famous 17th-century champagne trailblazer, Dom Perignon, was commissioned to remove the bubbles from the champagnes in his cellar.

Even two centuries after Dom Perignon, it wasn’t uncommon to lose half of your fermenting inventory to exploding bottles of especially bubbly champagne.

Less is More 

Champagne enthusiasts claim that the smaller the bubbles, the better the champagne. The thinking goes that when you have smaller bubbles in the same size glass, then there are more total bubbles on hand to deliver a full-bodied taste and richer aroma.

The actual bubbles in champagne are created through the secondary fermentation process that sparkling wine undergoes to eventually become champagne.

Though this secondary fermentation process, the sparkling wine becomes champagne and, in the same process, gets carbonated. Carbonation, or the infusion of carbon dioxide into champagne, is what makes champagne and soda alike fizzy or effervescent.

Unlike soda, though, champagne is created by taking select pinot noir and chardonnay grapes plucked from orchards in the Champagne region of France to ultimately deliver a creamy champagne tasting experience.

Research on Champagne’s Carbonation 

Although both soda and champagne, for all of their differences, each has an appreciable level of “fizzy” or carbonation, the carbonation is created in different ways for each beverage.

Champagne gets its bubbles and carbonated quality in a more hard-won way through secondary fermentation whereas soda gets its bubbles through an artificial process of a carbon dioxide injection.

In an interesting twist, though, research shows that the diffusion of carbon dioxide in sparkling wine and champagne are reasonably similar – much more similar than one would suppose given that champagne has smaller and more tightly packed bubbles.

It’s subsequently been shown that, although the amount of carbonation wrought by secondary fermentation has a lot to do with champagne’s fizziness, the bubbles in champagne are largely attributable to other causes.

It’s now believed that elemental minerals and naturally-occuring salts create more of champagne’s bubbles than was previously acknowledged (or understood) centuries ago.

Science Behind Champagne’s Bubbles 

Secondary fermentation and carbonation are fundamentally chemical processes that provide a real-world and visceral payoff for those of use who enjoy champagne.

One of the pleasures of champagne, if we’re going to be frank, is watching the tiny bubbles make their way up to the top of the glass and anticipating that first taste.

As these tiny bubbles make their brave trek up to the top of the glass, the bubbles themselves are transporting flavors and scents up the glass – and, hopefully, towards our parched mouths.

We almost automatically correlate a great tasting champagne with an explosion of bubbles at the top of our glass because more tiny bubbles means that more flavor and scents are traveling up the glass.

This spectacle, in the end, is half the battle when it comes to creating a creamy yet dry and savory champagne.