If you regularly buy wine you will have noticed that more often you are coming across wines closed with other than the traditional cork. Cork is the bark of a species of Mediterranean oak tree which can be stripped without harm from the living tree every ten years or so for generations. Cork has been used as a closure for wine bottles for more than 400 years. But it has one major fault, and a wine with that fault bears its name – the wine is ‘corked’.

If around 5% of all soft-drinks, or canned soups, or any other product were unusable because of faulty packaging it is unlikely their producer would remain in business. But wine-lovers expect, and have been expected, to bear the disappointment of spoiled bottles. Cork had no viable competition until recently when the cork industry began to be shaken out of centuries-old complacency by alternatives such as glass, plastic and screw-cap closures.

A closure is required, as a minimum to do two tasks. To provide a seal that stops the wine inside from getting out and to prevent anything from outside getting in to spoil the wine. Ideally the closure should not affect the wine and it should be easy to open when the wine is to be drunk.

Here is a quick overview of the strength and weaknesses of each closure:

Closure	For	Against	Comments
Cork	Fairly good seal Traditional Tried and tested Bio-degradeable	Can let in oxygen Affected by TCA = corked Affects wine with taste of cork Needs special tool to remove	There are different qualities of cork available depending on what wineries will pay. Expect cheap wines to have cheap corks
Screwcap	Excellent seal Easy to open, no tool needed Tried and tested	Good seal can cause ‘reduction’ Easy to reseal bottle	The market leader is Stelvin brand
Plastic closure	Wineries can use same machinery as used for corks	Seal doesn’t last Can affect wine with plastic taste Difficult to remove Difficult to replace in bottle	There are several manufacturers of plastic closures
DIAM	Fairly good seal Tried and tested Bio-degradeable	Can let in oxygen Needs special tool to remove Guaranteed 'corked' free	DIAM is a manufactured ‘cork’ made from powdered cork and guaranteed to be free of the chemical that causes ‘corked’ wines
Vinlock glass stopper	Looks good Easy to open, no tool needed	Seal is plastic ring Untried over decades
Zork	Tamper evident Easy to open, no tool needed Makes ‘pop’ when opened	Untried over decades

If you want to start an argument among wine lovers bring up the subject of wine closures. Battle lines have been drawn! George M Taber, who wrote the book that the movie Bottle Shock is based on, told me that he’d never come across any subject that was so contentious.

George M Taber went on to research and write a most readable book that tells the story of wine closures and the current situation and if you want to know about the battle to close wine bottles then I thoroughly recommend it. Taber’s conclusion is that no closure is perfect and that they each have their strengths and weaknesses.

---

Peter F May is the author of Marilyn Merlot and the Naked Grape: Odd Wines from Around the World which features more than 100 wine labels and the stories behind them, and PINOTAGE: Behind the Legends of South Africa’s Own Wine which tells the story behind the Pinotage wine and grape.

---

Too Cork or Not to Cork Even the most jaded wine lover will enjoy and learn from this well written, easy reading yarn about that essential but disposable closure that must be removed before we can enjoy our favourite drink. If you’re thinking of a present for a wine-lover, this book will not disappoint.

The Judgement of Paris This book is non-fiction, unlike the movie Bottle Shock that it inspired, and its more for the dedicated wine fan rather than the general reader. It tells the story of the 1976 tasting of top French and California wines and has a detailed look at each of the California wineries involved. Taber was the only journalist present at the tasting.