Once wine became popular in the Caucasus some 6000 years ago and exports to southern Iraq on the Euphrates River started. At the time wine was transported in tightly sewn hides of sheep. Much later, eventually ancient Greeks started transporting wine in earthenware amphorae with a capacity of a few litres of the precious liquid.
Wine transportation and trade in the Mediterranean basin from Lebanon to Spain was substantial, so much so that a whole suburb of Rome, Trastevere, is said to have been evolved on the shards of broken amphorae.
Of late Australians started exporting bulk wine to the United Kingdom in huge containers. The wine is bottled in England for retail distribution, saving valuable fuel and considerable amounts of money for wine consumers. For this to happen in every market volumes must be large enough.
Canned wine appeared a few years back but their anti-acid lining prevents long storage. Cans are light, protect wine from UV light and can be used for quick-consumption mass-market wines.
Cartons, of which 10 per cent is Tetrapack, invented in Sweden for milk, allow up to a year for cellaring. At least in Ontario they have not been successful. Plastic bottles (PET polyethylene terepthalate) are indestructible, light and can be used for wine storage up to two years. It cannot be recycled but down cycled to textile production.
A few Australian wineries attempted to ship in PET bottles to North America so far with limited success. Wine pouches are convenient. They keep wine fresh up to four weeks, fresh but the wines contain high levels of preservatives.
Bag-in-a-box was invented in Australia in the 1950’s for large format packaging. They are furnished with a spout for easy pouring, collapse as wine is drawn to eliminate oxygen penetration, but must be consumed within four weeks of opening. They may be appropriate in mass-market producing and consuming regions.
So far glass bottles are considered the best containers (750 ml. bottles range in weight from 450 grams to more than one kilogram). Glass bottles can be manufactured in a range of sizes starting from 187 ml all the way up to 15 litres.
In the 18th century the first glass bottles started appearing. Until recently, glass bottles were the most popular wine containers.
As of 1950’s, several wine packages have been introduced as glass is heavy, breaks easily, costs a lot to transport, and must be enclosed with a cork, or screw cap or some other substitute. Environmentalists, expressed their concerns about those disadvantages, but thus far experts agree that cork-enclosed bottle preserves wine best.
Screw caps are becoming more and more popular for mass-market to mid-market wines, but not traditionally expensive high-end wines. Cork remains very popular, but it has one big disadvantage in that if not properly processed it imparts 2,4,6TCA (trichloroanisol) contaminating smell and taste.
There are only seven countries that grow commercially viable quantities of cork trees (quercus suber). All are located around the Mediterranean basin, that enjoy climates and soils amenable to cork tree growing – Portugal (the biggest producer with 50 per cent of world supply), Spain, Morocco, France, Italy, Tunisia, and Algeria.
Portugal’s largest cork processors are Amorim, Alvaro Coelho, Ganau, Cork Supply Group, and Oenco spent a fortune to develop processes to eliminate cork-taint and has been able to Reduce 2,4,6 TCA occurrence significantly but not totally.
It is estimated that six to eight per cent of all cork-enclosed bottles are “tainted”, but unfortunately a lot of consumers do not know how to identify it, and therefore think the wine does not appeal to them.
Cork consists of dead suberose tissue and lenticels. Cells in the bark of the cork tree take the form of a 14-sided polydren. There are 20 – 40 million of these cells in one cubic centimetre of cork, and they are arranged in such a way that there is no void space between them The lenticels are channels which cross the cork and allow the exchange of gas between the three tissues and the outside. Their reddish colour is due to oxidation of the tannins. Cork contains 89.7 per cent of a gas mixture with elements other than air, nitrogen being the most common in the mixture. The remaining 10.3 per cent is composed of – 58 per cent suberin, 22 per cent cellulose, 12 per cent lignin, 5 per cent water and 3 unidentified substances.
The cork tree is a unique plant and grows only in Mediterranean climes that combine an annual precipitation rate between 400 – 800 mm. with temperatures never falling below – 5 C. The tree requires a sandy soil that is rich in potassium or phosphoric acid, with a pH value of between 5 – 6.
There are two types of cork.
“Virgin” cork, as the first variety is known, is hard and erratic in its growth, making it unsuitable for cork manufacture. It is only from the second variety, called reproduction cork, that wine bottle corks can be successfully produced; thanks to its superior flexibility and more regular growth pattern.
One of the most remarkable attributes of the cork tree is that once stripped, it regenerates its bark, but in order to protect the tree the following must be observed:
Before the bark is removed it must have achieved a growth of 80mm., that is generally achieved in 25 – 30 years.
Stripping must occur at a certain time of the year, generally between May and August.
During stripping, caution must be taken not to damage the phellogen. The life span of the cork tree is approximately 200 – 250 years.
The average growth of the bark is as follows:
First year 1.5 mm.
Second 3.8 mm.
Third 3.8 mm.
Fourth 3.6 mm.
Fifth 3.4 mm.
Sixth 3.0 mm.
Seventh 2.7 mm.
Eighth 2.4 mm.
Ninth 2.0 mm.