Natural vs. Synthetic vs. Screw Caps: Is the Great Wine Closures Debate Coming to A “Close”?

When a sommelier – or your spouse or friend – ceremoniously pulls the cork on a bottle of wine, the aromas of flowers or fruit should fill the air. But sometimes the unmistakable funky reek of mold wafts out instead, the hallmark of a “corked” wine.

It is generally agreed that 3 to 5 percent of all bottles with natural corks show some spoilage. As a result, plenty of cork substitutes have filled the market, and screw caps are becoming more commonplace. This means there are now three primary ways in which wine bottles are sealed: natural corks, synthetic corks or screw caps.  All have advantages and disadvantages, so let’s breakdown the widely recognized pros and cons of each:

Natural Corks:

  • Traditionalists claim that “real” corks allow healthy gas exchange for flavorful wine.
  • Some claim that good sources of natural cork are dwindling.
  • Not all natural corks are alike, resulting in variable cork properties.
  • Higher chance of “corked” wines and trichloroanisole (TCA) taint.

Synthetic Corks:

  • Synthetics close 60% of the top 500 wines (sold by volume) in the US.
  • There is an untrue perception that synthetic corks let too much air into the wine bottle. They actually help regulate and manage oxygen.
  • Injection molded closures were so hard to take out of the bottle that most of those companies are out of business. Co-extruded synthetics can easily be extracted or reinserted into a wine bottle.

Screw Caps:

  • Less chance that wines will be “corked,” and probably fewer tainted wines.
  • Some say that air-tight screw caps are “suffocating” to wines.
  • Still considered by some to be the hallmark of a cheaper product.

Getting the real story:

To help winemakers determine the best caps for their wine bottles, researchers here at UC Davis are studying the performance and the variability within different types of closures. They are evaluating 600 bottles of Sauvignon Blanc wine, each sealed with natural cork, screw caps or synthetic cork. Their goal is to determine whether consumers can taste the difference in wines bottled and capped under the exact same conditions.

The study will monitor changes in the wine during aging, culminating in a sensory evaluation to determine if wine experts and consumers can taste the different levels of oxidation that occur in the wine due to variability within each type of closure.

Interested in learning the outcome of this study? Join us June 3 – 4 for Wine Packaging Strategy: Decide, Design, Impress to gain access to cutting edge research like the closures study, along with newly developed insights and tools from esteemed academic and industry professionals. Participate in curated conversations about key topics such as consumer behavior, market fads and trends, closures, sustainability and branding while extending your network of wine executives. Contact us with questions about the program!