April 2008 Cyprus wine blog

Dear friends of Monolithos,

Selecting the most appropriate bottle closure for a particular wine is another controversial topic in the wine world that has triggered considerable debate in recent years. This short article will investigate questions which are of interest to consumers, collectors and wine lovers. However, it is important to look first into the history which brought about the extensive use of cork as a wine stopper.

Wine and cork are two products that have long been companions. The ancient Greeks used corks sometimes to close wine jugs. Proof of this is an amphora from the 1st century BC found in Ephesus: it was not only was sealed with a cork stopper but also still contained wine. Following in their footsteps, the Romans too used cork as a stopper and also coated corks with pitch to seal the closure. In Pompeii, the Roman city destroyed by the eruption of Mount Vesuvius, wine amphorae sealed with cork have also been found.

The use of corks was apparently completely given up in mediaeval times. We find corks beginning to be mentioned again at the end of the 16th century. Cork’s success as a closure depends upon its fitting snugly into an opening with a relatively uniform diameter. Thus, it was not until the 17th century, when glass bottles were first made with more or less uniform openings, that cork truly became popular. The popularity of cork as a stopper led to deliberate cultivation of cork trees, which prior to about 1760 had simply been harvested wherever they happened to grow.

Many wine historians have linked the development of the glass bottle and its cork stopper as two necessary prerequisites for the modern international wine trade. Wine no longer needed be shipped in bulky, awkward clay vessels or wooden barrels. The economies of space enabled ships to carry more wine and the wine was much less subject to spoilage in the shipment. Because cork stoppers prevented oxygen from spoiling the wine, both in shipment and in subsequent storage, it became evident that wine benefited from its maturing time in the bottle. The desirable properties of aged wine made it more valuable and collecting and cellaring wines from many different regions became both feasible and profitable. In the almost 300 years intervening between the renewed usage of cork and the end of the 20th century, cork has been the overwhelming closure of preference for fine wines around the world.

The vast majority of corks are made from the bark of the oak tree Quercus Suber, and come from the oak forests of Portugal. Virtually all of the world’s commercial cork trees grow in the western Mediterranean region and the Iberian Peninsula. Portugal's cork forests are the most productive. Accounting for 30% of the existing trees, they produce half of the world’s harvested cork. After planting, a cork tree is ready for its first commercially acceptable cork harvest when it is about 40 years old. Subsequent harvests occur at nine-year intervals, when the cork layer reaches a thickness of 1-2 in (2-5 cm). The bark is then removed from the tree once it is thick enough for industrial exploitation. Each tree has a productive life of about 150 years.

There are several very sound reasons for cork’s continuing popularity. Cork’s component materials and structure give it a unique set of physical and mechanical properties that make it ideal as a bottle closure. Some of the most important are its lightness and its resistance to moisture penetration. It can be compressed to half its dimension with no loss of its flexibility, and it can be compressed in diameter without expanding its length. When removed from compression, cork will recover about 85% of its initial volume immediately and more than 98% after 24 hours. It has an exceptional power of adhesion to wet, smooth surfaces, it is stable in temperature changes, it exhibits age stability and is biodegradable. Cork is the only material known that compensates for small imperfections in glass.

Cork is composed of tiny air-containing cells. In fact, the cork is a time capsule of the air that was present during the eight years the bark took to grow back to the proper diameter to be harvested. The cell walls contain suberin, a waxy substance that makes cork water-resistant. Over half of the volume of cork is empty space, which is why it floats in water and is easily compressible into the bottleneck. Natural cork’s flexibility allows it to conform to irregularities of the bottleneck. Cork became the traditional wine closure centuries ago, principally because it was the only material available for the job at the time, back when homes were lit by candles and oil lamps.

The job of the cork, whatever it may be made of, is to prevent oxygen from coming into contact with the wine, thereby oxidizing it. A good closure serves two purposes: it keeps the liquid in the bottle and it keeps the oxygen out. Added to this is the economics of the operation, where a relation must exist between the cost of the closure and the quality of the wine. With these objectives in mind, a first consideration for the producer will be the different types of closures available.

There are several different types of wine corks available. Type selection is dependent on the type of wine being sealed and the expectant length of time before the wine is consumed. Other factors determining wine cork type selection and treatments include bottling speed, still or sparking wines, sweet or dry wines, red or white wines, bottle size and type. There are alternatives to the standard cork, however, the motives behind these alternatives are in sometimes financial, and in some cases a quest for quality and consistency.

A fairly standard natural cork comprises a single piece of bark of about 24 mm diameter. This is about 6 mm wider than the internal diameter of the neck of the average wine bottle, which ensures a tight fit, provided the cork doesn’t dry out and contract.

Natural wine corks are “punched” from specially selected corkwood, carefully inspected for flaws, washed, sterilized, and printed or fire branded. There are seven standard grades of natural wine corks carefully sorted into respective quality grades, first by automatic laser sorting machines, followed by final manual hand sorting. Wine corks are available in a wide variety of both standard and custom sizes, the most common being 45 mm long x 24 mm diameter and 38 mm long x 24 mm diameter. The technical specifications are the same for all sizes. The diameter of the cork is on average 24 mm. The jaws of the corker compress the cork to16 mm to fit it into the bottleneck. After insertion, the cork bounces back to 18 mm – the diameter of the bottleneck – which means that 6 mm or 25% of the cork is pushing out against the glass to create the seal. To improve the seal, the cork is coated with paraffin, which repels wine and Silicone, which acts as a lubricant to ease insertion and extraction.

Another popular type of cork is the double disc or twin top cork. This type of wine stopper is a combination of agglomerated cork (forming the main body of the stopper) and natural cork (the ends of the agglomerated body are laminated with natural cork discs). The discs are available in several different qualities. The benefit of these highly technical stoppers is consistency of density, quality, function and price.

Another product made of natural wine cork is the colmated or pore-filled cork. In this case, the pores in natural wine corks are filled and sealed with a mixture of fine cork grains and FDA approved resins. Due to the economical cost of these stoppers, pore-filled wine corks are ideal for volume wines. The technical specifications are similar to those of natural wine corks.

An agglomerate cork is manufactured from tiny pieces of chopped cork, bound together by glue. The motive behind this closure is financial – the process allows for otherwise wasted pieces of oak bark to be made into something saleable. These stoppers are manufactured from clean natural cork grain. The grain is milled using the “waste” by-product from natural wine cork production. Agglomerate wine corks are economically priced and easy to use. Maintaining the agglomerate stopper technical specifications ensures successful sealing and good performance.

During the production of bottle stoppers, chemical baths are used to condition the corks. Among the more popular are a chlorinated lime bath followed by a neutralizing bath of oxalic acid, a hypochlorite bath neutralized by sodium oxalate, and a peroxide bath neutralized with citric acid. Production of compound agglomerated cork involves adding a binder or adhesive agent to cork granules. Different binders are chosen, depending on the qualities desired in the ultimate product (e.g., flexibility, softness, resistance to wear). Among those frequently used are asphalt, rubber, gypsum, glue, and plastic.

Natural cork is very light, and it's natural tendency to dry out and shrink can easily be counteracted by keeping it constantly wet and "nourished" by the wine it comes into contact with. Thus the cork stays elastic, and once inside the bottleneck it adheres to the sides, perfectly sealing the bottle. This is why naturally corked bottles should always be kept lying almost horizontally with the bottle, neck slightly angled downwards. In fact, in wine cellars, specifically made bottle racks keep the bottles at just the right inclination for exactly this reason.

In addition to drying out, two other enemies of natural corks are fungus and mould which can contaminate the cork tree or the corks themselves during fabrication. When this unfortunate event occurs, the wine takes on an unpleasantly bitter smell. Today, this is prevented by washing the corks in hot water or subjecting them to a micro-wave treatment.

Even though every problem has a solution, the risk remains: at the moment of buying a bottle of wine, there is no way to ascertain the condition of a natural cork. It's always best to shop in a trusted wine shop or at least a well-known one, if you are buying very fine wine. Once in the store, it is advisable to choose wine bottles (with natural cork) that are lying down in the rack, instead of bottles that are standing up straight.

The major disadvantage of cork and the reason for searching for alternative closures is TCA (2-4-6 Tricloroanysole). The latter is responsible for the unpleasant tainting which gives a powerful fungal aroma and flavour to the wine, and that accounts for almost 4% of faulty wines produced. It originates in a reaction between a penicillium mould in the crevices of the cork and the chlorine-containing chemicals used in the sterilising process.

Because of the significant number of natural corks that are contaminated which result in corked wine (a generally accepted figure is about 5% of all bottles), many winemakers are opting for alternative methods of closure such as synthetic and glass closures and screw caps . Many claim that a natural cork is in and of itself synonymous with indisputable quality in a bottle of wine. However, expert opinions don't all agree. In fact, lately it's not unusual to find even bottles of fine wine with synthetic corks.

In summary, the secret to cork performance is its unique cell structure, which technology cannot replicate. Cork consists of a honeycomb of tiny cells made from suberin, a complex fatty acid, and filled with an air-like gas. There are on average about 40 million cells per cubic centimetre of cork, or around 800 million cells in a single wine cork. Cork's cell-like structure makes it easy to compress and thus less liable to damage from corking machines. Amazingly, the cork is capable of being compressed to about half its width without losing any flexibility, and it is the only solid that can be compressed in one dimension without increasing in another dimension.

The cushion-like cork cells also display what is known as elastic memory. When compressed, they constantly try to return to their original size, thus maintaining a tight seal. This means the cork exerts a very even pressure against the surface of the bottle neck and can compensate for imperfections in the bottle. Being elastic, cork is also more tolerant than other materials of changes to temperature and pressure. In addition to these characteristics, cork's lightness and chemical inertness make it ideally suited as a wine closure. Cork resists moisture and can age for long periods without deteriorating.

Cork is also a natural product, recyclable and biodegradable. From this perspective, natural corks are one of the best materials for carrying out its protective function, provided it is of optimum quality.

Wine News and Information

UK wine drinkers are set to become the most heavily taxed in Europe after the government announced a 14p increase on a bottle of wine. The shock decision comes as consumers already face price increases on the back of rising costs for grapes, packaging, glass, transportation and energy. The increases, announced by Chancellor of the Exchequer Alistair Darling in his first budget, are set at 6% above the rate of inflation. They will create a £1.46 duty burden on a 75cl bottle of wine – 7p higher than the rate in Ireland, previously the most highly-taxed wine market in the European Union. The rises also mean 18p more on a bottle of sparkling wine, 20p more on a bottle of fortified wine and 55p extra on a typical bottle of spirits. A pint of beer will be 4p more expensive, while cider goes up by 3p per litre. Jeremy Beadles, chief executive of the Wine & Spirit Trade, stated that: “It is bizarre at a time when the economy is slowing, that prices are rising and many families are feeling the pinch that the Government should choose to add to their burden by making the simple pleasure of a glass of wine or spirits considerably more expensive.”

Peter Spencer, senior vice president sales for Constellation Europe, said that Constellation would have to pass the increase onto the consumer. “I believe this duty hike will mean that prices across the wine category will rise substantially, and that it will herald the end of wine at the £3.99 price point, as it is simply unlikely that any wine producer can supply wine at this price.”

South African Wine Council chairman Professor Kader Asmal has announced wide-ranging responsibilities and targets for social transformation in the wine industry. The issues to be tackled include a responsible alcohol use master plan, rural development and poverty alleviation, security of tenure and matters relating to farm evictions, and sectoral determination and employment conditions. Asmal said the improvement in the quality of life of farm workers “as a most vulnerable community in the wine industry” had to be seen as an important development indicator. Asmal said land reform, which was incorporated in the wine charter, was viewed as an “important element of transformation and social stability in the wine-lands”. He said successful social transformation in the industry would be subject to “mutual respect and co-operation of all parties involved”, and would not compromise sustainability or international competitiveness.

Monolithos Monthly News

The growing season is officially underway. Bud-break begins and new spring greenery is easily visible in vineyards. Bud-break is an annual stage in the growing season when vine buds crack open and small shoots emerge. It marks the end of the winter dormancy and the start of the new crop. Springtime sunshine warms up the hill sites and coaxes bud growth on vines. Vineyard owners are mostly engaged in soil management at this time of year. This means the row space between the vines is being machine cultivated or mowed, depending on the vineyard’s soil.

At the winery wine racking, cold stabilisation and bottling of last year’s vintage is in progress. All eight Monolithos premium wines are available for tasting or purchasing, so if at any time you are passing near the village of Pachna and wish to visit the winery, Martin Wood will be pleased to meet and assist you at his “Fig Tree Villa” in Pachna, so do not hesitate to phone him at 25-816212 or 99-165995.

Regards from all of us here at Monolithos and always remember the words of Douglas William Jerrold (1803-1857), British Humorist, Playwright:

“Marriage is like wine – it is not to be properly judged until the second glass.”