Wine Closures

There’s More Than One Way to Close a Wine Bottle

Each year we spend some time at the Jersey shore in Avalon. At Quahog’s, a BYOB in Stone Harbor, we brought in a bottle of chardonnay to enjoy with our seafood, and we were surprised when the waiter placed a glass “cork” from our bottle on the table. I’ve seen regular corks, engineered corks and even plastic/rubber-type corks, but I had never seen a glass cork before. This got me thinking that it might be nice to do an article that tells a little bit about the different kinds of wine closures and their pros and cons.

In my research, I’ve found several different types of wine closures, and all of them, as you might guess, have some good points and bad points. After all, if one type was 100% great, there would have been no need to come up with alternate closures in the first place.

Natural Cork is harvested from the Portuguese cork tree. The trees are a type of oak tree. I had no idea that my wine cork started from an acorn! The trees must be at least 25 years old before starting harvesting, and the bark from each tree is stripped once every nine years. This ensures that the tree has plenty of time to regenerate and flourish between strippings.

Once stripped, the cork “planks” sit out to dry. Then, they are boiled. This might sound strange, to boil after drying, but the dry-boil-dry process both removes impurities that can cause cork taint from the cork and standardizes the final moisture content.

This allows the cork maximum compressibility as well as breathability, allowing the cork to provide a leak-proof seal for wine bottles as well as providing slow oxygen exchange. It is this very slow exchange that makes natural cork so good for bottles that are meant to age for years or even decades before drinking.

Technical Cork is made in part from a lower-grade cork than natural corks and the leftover bits and pieces from trimming natural corks. To make a technical cork, many cork granules are pressed together with a food-safe binding agent. Then, they are either injected into stopper molds or are extruded like pasta.

In some technical corks, thin cork discs are glued to the bottom and top of each stopper. This is called a 1+1 technical cork. Other manufacturers glue two discs of cork to the bottom of each stopper. This is called a 2+0 technical cork.

Synthetic Cork is manufactured to look like natural cork, at least in size and shape, if not in texture. Synthetic corks are made from plastic that is either injected into molds or extruded. Unlike with natural corks or technical corks, synthetic cork eliminates the possibility of cork taint. They can be very difficult to remove from bottles (not to mention re-sealing), and they are not biodegradable like natural cork, thus they have a negative environmental impact.

Screw Caps, also known as Stelvin Closures, seal very tightly and are easy to reseal. Sealing tightly is a twin-edged sword. On one hand, they don’t leak. On the other hand, there is no chance for the slow oxidation that can occur with natural cork. As a result, Stelvin closures are not generally recommended for wines meant to age longer than 3-5 years.

Screw caps also suffer from a perception problem — wine in a screw-top jug just doesn’t sound very classy. But, Australian and especially New Zealand have embraced this type of closure, and I have been seeing more and more American wines with Stelvin closures as well.

At first I was a little apposed to screw tops but now I’ve warmed up to them especially on what we call maintenance wine, the less expensive wine we drink during the week. And if a screw-top can eliminate the issue of cork taint, I’m on board with it.

Zork is the brainchild of an Australian with the same name. They offer closures for still and sparkling wines. The Zork has an outer strip of plastic wound a couple of times around the neck of the bottle. You peel this part off, just like opening a container of milk.

The cap itself is lined with a foil barrier that does allow for slow oxygen transfer, making the Zork a viable closure for wines meant to be aged. There is also a plastic stopper portion that extends into the neck of the bottle, like a cork. And like a cork, it even makes a popping sound when removed.

The Vino-Seal is an elegant glass stopper that has a plastic, non-reactive O-ring that provides an airtight seal for the wine. I can attest to how cool they look, having just purchased a wine with closed with a Vino-Seal during our latest vacation in Avalon.

Each seal is more expensive than many of the other closure options out there, and the machinery for bottling isn’t currently available in the United States. That means hand sealing, unless the machinery can be brought over and sold at a reasonable price.

Here’s a handy chart showing the types of closures, their pros and cons, and the cost of each closure.

Closure Type	Pros	Cons	Cost per Closure
Natural Cork	Caché–part of the ceremony of drinking wine, most prevalently used, suitable for long aging, natural product	Can dry out and crumble causing, leaking so bottles must be stored on their sides, possibility of cork taint, resealing, as more and more wines are made, it’s harder to have enough cork trees to go around	$.10-1.50
Technical Cork	Look and act like natural cork	Possibility of cork taint, resealing	$.10-.17
Synthetic Cork	Look similar to natural cork, no cork taint	Not suitable for long cellaring, removal/resealing, environmental impact	$.10-.16
Stelvin Closure	Tight seal, resealable, no cork taint, clean and simple closure	Not suitable for long cellaring, perception issues (“lower-class”)	$.05-.10
Zork	Cool name, pops when opened, no cork taint, doesn’t need a foil cover, resealable	Price, especially in relation to Stelvin closures	$.18-.25
Vino-Seal	Elegant, resealable, no cork taint	Cost of product and cost of bottling equipment	$.64-.67