Spill the Wine

Last week I wrote about wine bottles and where the different shapes came from so I thought this week I should really address wine closures to help demystify the array of ways producers are stopping up their bottles.

The most well known wine closure is of course the cork. The natural cork comes from a tree grown in the Mediterranean. The cork can be removed from the tree without hurting the tree. Natural corks are still used in over 80% of wines bottled today and many would argue that the cork is the best closure for wines you wish to age. The argument is the cork material holds pockets of air allowing just the right amount of oxygen into the bottle to foster the very best aging process. Unfortunately a small number of corks fail and lead to “corked” wine. Cork taint is caused by the presence of the chemical Trichloroanisole (or TCA).

Synthetic corks are made from plastic compounds designed to look and “pop” like natural cork but without the risk of TCA contamination. The concern with this type off closure is its ability to properly seal the bottle long term and the difficulty in removing it from the bottle. Some argue they impart a slight chemical flavor to wine. These closures are recyclable but not biodegradable. There is talk of a new generation of these injection molded closures that have developed a system of nano-cells as to perfectly replicate the cellular structure of natural cork.

And then there is the screw cap also know as “Stelvin caps”. These closures are made from aluminum material that threads onto the bottleneck. They are the predominant closure used in New Zealand and form a tighter seal and keep out oxygen for a longer time then cork. They are said to promote aromatic freshness while still allowing the wines to age and eliminate the problem of cork taint. But as with every type of closure there is a down side. Unlike the real cork the screw cap does not allow even the smallest bit of oxygen to mix with the wine and therefore the wine ages differently then with the more traditional cork. Some screw caps may also be affected by the chemical process sulphidisation resulting in some wines forming bouquets of burning rubber or rotten eggs.

The “Vino-Seal” or “Vino- Lok” is a plastic or glass closure. Using a glass stopper with an inert o-ring, the “Vino-Seal creates a hermetic seal that prevents oxidization and TCA contamination. These are primarily used in Europe and have their down side too. Each one is very expensive and make it necessary to hand bottle as there is not compatible machinery yet to take on this role. And how wines age with these tops is still in question as they are relatively new.

The Zork is an alternative closure that seals like a screw cap and pops like a cork. The Zork closure has an inner metal foil similar to a screw cap and an inner plunger which creates the pop like a cork.

The crown cap, just like that used on beer bottles has been used as a closure for sparkling wines during the fermentation process. Normally the cap is replaced with a cork before shipping but some producers are releasing wines using the crown cap eliminating the cork taint possibility, while providing a tight seal. Easier to open but without the pop.

I can’t help but prefer the real cork and will take my chances with the very few times a bottle ends up corked. And it isn’t because of the pop - I just think they are superior for aging wines. But my preference for the “real” thing does not mean I would not buy or have not enjoyed wines with other closures. Each one has its pros and cons and I am too interested in experiencing everything wine has to offer to draw any lines in the sand with regard to the top of the bottle.