Wine 101: What’s the Deal With Corks?

Originally published April 15, 2016. Updated in 2026.

Pop a cork and you immediately know what sound you’re hearing. For generations, natural cork has been so closely associated with wine that opening a bottle became part of the experience itself.

But cork isn’t the only way to seal a bottle of wine. Screw caps and other closures have become common around the world, including on many very good wines. So why does one bottle have a cork while another has a screw cap?

What Does a Wine Closure Actually Do?

At its most basic, a closure has an important job: keep the wine safely inside the bottle while limiting the amount of oxygen that enters after bottling.

Different closures accomplish that job in different ways. The choice can depend on the style of wine, how long it is expected to age, the winery’s bottling equipment, cost, tradition, and the winemaker’s preferences.

Natural Cork

Natural wine cork comes from the bark of the cork oak tree. The bark can be harvested without cutting down the tree and grows back so it can be harvested again years later.

Cork has been used to seal wine bottles for centuries. It compresses when inserted into the bottle and then expands against the glass, creating a tight seal.

For many wine drinkers, cork also has tradition on its side. Pulling a cork is simply part of the ritual of opening a bottle.

What About Cork Taint?

Natural cork isn’t perfect. A small percentage of cork-sealed wines can develop an unpleasant musty or damp-cardboard character commonly known as “cork taint.” One of the compounds most often associated with this problem is TCA.

Modern cork production and quality-control methods have greatly reduced the problem, but the possibility of cork taint is one reason wineries have explored alternative closures.

Screw Caps Aren’t Just for Cheap Wine

A screw cap is not an indication that the wine inside is inexpensive or lower quality. Many wineries use screw caps because they provide a consistent seal, are easy to open, and eliminate the risk of cork taint from the closure itself.

Screw-cap bottles are manufactured differently from bottles designed for cork. Instead of the smooth neck used with a traditional cork closure, the bottle has a threaded finish designed to accept the cap.

The bottling equipment is different as well. A corking machine compresses and inserts a cork into the bottle, while screw-cap equipment applies and secures the cap around the threaded bottle neck.

Does the Closure Affect Aging?

It can. Different closure systems allow different amounts of oxygen to reach the wine over time, and winemakers may consider that when choosing how a particular wine will be bottled.

But there isn’t a simple rule that cork is for good or age-worthy wine and screw caps are for everything else. Excellent wines can be found under both types of closure.

So Which Is Better?

There isn’t one closure that’s automatically best for every bottle. Natural cork offers tradition, renewable material, and a long history with wine. Screw caps offer consistency, convenience, and freedom from cork taint.

Ultimately, the closure is one of many decisions made before a wine ever reaches your glass.

And whichever closure is on the bottle, the most important part is still what’s inside.