Is Storing Wine with Synthetic Corks Different from Storing Wine with Real Corks?

storing wine with synthetic corks

Synthetic corks are made of stiffer material than real cork, which means they don’t always maintain a proper seal when the glass of the wine bottle contracts or expands. Photo Credit: Flickr CC user Sam Howzit

I’m reasonably skilled at opening wine bottles, but I’ve had quite a few synthetic corks break in half recently. One was a high-quality bottle of Oregon Pinot Noir whose synthetic cork was sealed so tightly to the neck of the bottle that it broke off into four separate chunks as I tried to pry it out. Usually, it’s not that the corks themselves are poorly made; the problem is that synthetic seals tend to get too loose or too tight depending on the storage temperature. Storing wine with synthetic corks requires more care than storing bottles sealed with real cork because synthetic corks are more sensitive to temperature change. Ideally they need to be kept at a steady temperature, without any fluctuation whatsoever. Knowing the best way to store these bottles with these types of corks will prevent your wine from spoiling and make it easier to open your bottles without getting chunks of cork in your glass.

Store Wine with Synthetic Corks Short-Term

The difference in performance between synthetic corks (made from a plastic called polyethylene) and real corks (made from a tree in the oak family) comes down to how effectively they allow a wine to oxidize over time. When an age-worthy wine is very slowly exposed to small amounts of oxygen, its flavors mature and the wine becomes more valuable. However, too much oxygen entering the bottle too quickly will spoil a wine’s flavors, making it taste and smell like mold or wet newspaper. Corks are designed to control the amount of oxygen that leaks into the bottle during its lifetime. Cheaply-made plastic corks often let in too much or too little oxygen–with too much oxygen, the wine spoils, and with too little, the wine doesn’t mature at all.

Quality synthetic corks that are properly fitted to bottles, however, can be just as effective as real corks when it comes to oxygen balance. This is why in most young bottles, the difference between storing wine with a synthetic cork and storing wine with a real cork is negligible. As long as the winery gets its corks from a reputable manufacturer and you keep your bottles stored at a consistent temperature, you will have success buying bottles with plastic corks. To check whether a cork is of decent quality, look for a glue casing; some cork makers seal the plastic with glue, which means that no oxygen can get into the bottle. You can also research whether a particular wine vintage has a plastic cork by visiting CORKWatch.

Storing Long Term Requires More Care

The only time that storing wine with a synthetic cork differs from storing wine with a real cork is when you want to age a bottle for at least ten years. Although synthetic corks let in a consistent and predictable amount of oxygen over time, they can become unpredictable when temperatures rise or fall in your cellar. This is because synthetic corks are made from stiff plastic. Glass bottles naturally expand and contract with changes in the weather, growing slightly larger in the heat and shrinking in the cold. Even though this change in size is very minor, it’s enough to create too much or too little space between the inside of the bottle and the edge of a stiff plastic cork–the cork remains the same size while the bottle shrinks or expands.

In bottles that require long-term aging, any slight change in the position of the cork could lead to disastrous results for the wine. Collectors usually drink young wines before they’ve had the chance to spoil from an improperly sealed cork, but with age-worthy wines, they might not notice the problem until it is too late. That’s why real corks are the best option for age-worthy vintages. Unlike plastic, real cork is flexible, expanding and contracting easily alongside the glass bottle.

Storing Bottles with Synthetic Corks

The good news is that almost every valuable, age-worthy bottle you encounter on the market will have a real cork, rather than a synthetic one. Many winemakers realize that real corks are better for long term storage than plastic ones, and you will rarely find producers in Old World terroirs that use synthetic alternatives or screwcap tops. Be more careful when you invest in New World wines; these regions are younger and more willing to break tradition by trying new techniques, including using cork alternatives.

It doesn’t matter whether you store bottles with synthetic corks on their sides or upright. While you should always store your real cork bottles on their sides to keep the corks supple and prevent leaks, the benefit of a synthetic cork is that you don’t have to worry about the cork drying out, so you can keep your bottles upright if it suits your storage needs better. Plan on drinking any bottles that have plastic corks within five years or less, and check on your bottles at least once a month to make sure the cork seal looks tight enough. If you have a synthetic cork bottle that you want to save for a few years, I recommend sending it to a professional warehouse where the temperatures are monitored very precisely and are more likely to be consistent than in a home cellar. The more stable your temperatures, the less likely your cork seal will be disrupted, and the more likely you will end up with a mature, delicious wine in the future.

Whether you are starting your high-end wine collection or adding to an established portfolio, Vinfolio is your partner in buying, selling, and professional storage. Contact us today to get access to the world’s best wine.

With over a decade of experience in the wine industry, Derek Cienfuegos serves as Director of Collector Services at Vinfolio. During his tenure at Vinfolio, he has had the good fortune to work with some of the most distinguished wine collections in the country. Trained in wine production, Derek spent many years making wines commercially for some of Sonoma’s top producers. In addition, he has designed, opened, and managed two wine bars in San Francisco.