Closures: Cork, Silicone or Screw Cap?

We are increasingly accustomed to opening a bottle and pulling out a silicone stopper. Even when the bottle has a screw cap, we “uncork” it, a clear indication that as far as closures go, cork is still king.

But does the way a bottle is sealed really affect the preservation of wine and how it develops in the bottle? Yes, definitely.

Regardless of type, bottle closures are necessary for the proper preservation and development of the wine, as well as its transport. Wine needs to breathe, because the gradual ingress of oxygen is essential to its proper development. Within this process, the stopper is a crucial element in making sure the wine reaches your glass in the best possible condition.

So, what effect does each closure have on the wine?

The cork

· Cork is a flexible and porous material that adapts to the bottle. Therefore, oxygen can enter the bottle in a relatively controlled manner based on how porous the cork is. This is a decisive factor in determining the proper development of the wine.

· The best way to store a bottle under cork is in a horizontal position, which moistens the cork, allowing it to expand and create a much tighter seal.

· Despite its many virtues, there is a “but,” which has driven studies aimed at finding alternative bottle closures: the possibility of TCA contamination, known as “cork taint.” TCA (trichloroanisole) is a substance that develops as the organic compounds—phenols—normally present in grapes, cork, barrels, etc. begin to break down and combine with chlorine (used by some winemakers to bleach the cork).

The silicone stopper

· Silicone stoppers come in a variety of colors, including some designed to look like cork, and guarantee that the wine will remain inert inside the bottle. There is no oxygen contact at all. This makes silicone a good choice for young wines meant to be consumed within a relatively short time.

· These stoppers are not suitable for long cellaring: it is a known fact that silicone starts to shrink after about 3 years, which would significantly accelerate the wine’s development and result in a loss of liquid.

· Studies exploring alternatives like perforated silicone stoppers, which would make it possible to control the oxidation of the wine, are underway. Although they seem like a promising solution, high production costs make their standardization impossible in the short term.

The screw cap

· Screw caps are clearly a solution for those who prefer practicality to the ritual of popping a cork.

· It is increasingly common for quality young wines to be sealed under screw cap. Its easy functionality and attractive price are points in the screw cap’s favor. They generally enjoy far greater acceptance in countries that don’t have a long-standing wine tradition, particularly in northern Europe.

· But, just like the silicone stopper, the screw cap only offers a reliable solution for wines meant to be consumed shortly after bottling. That being said, studies are also underway to see if micro-perforations would allow the wine to develop in a satisfactory manner.

More information:

http://www.acenologia.com/innovacion/tapones_calidad_inn0913.htm