As a wine lover, I’ve always viewed wine corks as simply an obstacle between me and my wine, but a visit to Nova Cortiça near Faro, Portugal, gave me a new respect for the humble wine cork.

Nova Cortiça is one of over 300 family run cork processing plants in Portugal. 50% of the world’s supply of cork is produced in Portugal, 30%  comes from Spain and the remainder comes from southern France, Italy, Sardinia, Corsica and Northern Africa.  The Italian and African grown cork tends to be more brittle because of the drier climate.

Cork has been used to stopper jars and bottles for centuries, but the Benedictine monk, Dom Pérignon, who was cellar master at the Hautvilliers Abbey in the Champagne region of France, is credited with developing a cork to contain sparkling wines in the 1670s. The Benedictine monks continued to refine his methods over the next 200 years.

This is Virgin Cork, the first to be cut off the tree when its 25 years old. This cork will be used for insulated mats,  cork sandal soles, corkboards but is too porous for wine corks.

Cork production is immensely profitable but certainly not a get rich quick business. Cork can’t be harvested from a tree until it is at least 25 years old, and it will be at least 43 years old before the bark is dense enough to make wine corks. Most cork oak plantations have been family-owned businesses for generations.

Cork is harvested in the summer months between May and August as the heat makes the cork more flexible and easy to pry off without damaging the tree. In fact, prudent harvesting is good for the tree encouraging its growth and prolonging its life.

Once the cork has been harvested off the central trunk and larger limbs, (never branches with a circumference of under 60 cms) the cork trees must have a nine-year reprieve before the next harvest. Fortunately, cork oaks can live for 250 years or more so they can contribute a lot of wine corks in their lifespan to generations of farming families.

A cork’s flexibility allows it to take the form of many different bottlenecks.

The pork industry keeps the farmers solvent during the nine year gaps as the cork oak trees produce an abundant crop of acorns every year – an ideal organic feed for pigs and boars.

Cork is totally organic, no chemicals are used in its growing or production. Prior to processing, the slabs of cork are boiled in water for an hour to kill off any bacteria or fungi  The dead fungi can leave a residue that discolours the cork, Stringent quality control measures are used to discard any corks with yellow stains as they can interact with traces of chlorine from the wine bottle sterilization process. The result is a “corked wine” with notes of soggy cardboard.

The most expensive corks are made from solid cork but many of the cheaper corks are made from cork granules that are moulded together under pressure with a natural gelatin based glue, often they have a solid cork disk bonded to the base to strengthen the cork for extraction.

Although metal screw caps, plastic stoppers and synthetic corks are gaining in popularity they have 20 times the carbon footprint of biodegradable cork and while they are effective for wines with short shelf lives, good wines that need to be aged,  do much better in corked bottles.

What do you do when a wine waiter offers you the cork?  Sniff it to see if it smells of good wine. If it smells bad, the problem was with trace yellow fungal residue in the cork and the wine will be bad. The cork may smell good but the wine may still taste bad due to improperly cleaned bottles, faulty fermentation or too long an aeration.

How can you stop a cork from splitting when you are trying to extract it? Ensure that your corkscrew goes through the base of the cork, often this is where the solid disk has been attached. The centre of the cork is usually made of compressed  granules which break apart easily but the disk will not break under the strain

Why does a cork sometimes spin when you are opening a bottle? The bottle has been stored standing up for too long and the cork has shrunk allowing for air seepage. The wine will probably taste bad. Wine should always be stored on its side to keep the cork expanded. This is one of many good reasons to buy from a winery and not the liquor store.

I found this fascinating video on Youtube showing the cork harvest in Portugal produced by Corkie TV in 2010 https://www.youtube.com/watch?v=ztr-RP0XYd8 . Enjoy.