Grape Juice and Wine

Grape Juice and Wine
Ancient Egyptian inscription indicate that the grape was grown there in 2375 B.C. Murals to Egyptian tombs carry depictions of grape vines, grape harvesting, and trampling to obtain the juice.

By way of classical Greece and later Rome, the grape vine expanded into all the lands of Europe and North Africa where it will grow.

The Greeks cultivated the grape vine wherever they went; Italy, north Africa, southern France and southern Spain, including the best known wine regions of the world, Bordeaux and Burgundy. The Greeks called Italy the Land of Vines.

Romans grew different varieties and appreciated their diversity. Grapes were grown on trees and trellises, preferentially on terraced hills and banks surrounding river valleys. Romans aged wine in barrels, which they invented. Before then it had been kept in earthenware amphorae.

Grape juice changes naturally into wine when sugar fermenting yeast is present. When grapes are crushed with the skins, yeast comes in contact with the juice. It grows in the juice, using the sugar as its source of energy, and in process transforms the sugar into alcohol and carbon dioxide.

Alcohol in high concentrations is toxic, and when it reaches a certain level (between 12 and 14 percent), most strains of yeasts cannot grow any more. The wine is now ready. It is young wine and tastes very much likes grape juice alcohol. When the first fermentation is completed (sometimes even before), and especially if the wine is in a warm palace and exposed to the air, special bacteria start growing on the alcohol and transforming it into acetic acid. The wine spoils and turns to vinegar.

Since remotest antiquity, the principal problem was not to make wine but to keep it from spoiling. In classical Greece wines were drunk young and most were probably vinegary. To counter the acid taste a variety of methods were employed. Greeks learned that air speeds up the spoiling process. Amphorae had narrow necks to reduce the contact of wine with air, and they were kept tightly stoppered.

Because air could penetrate earthenware surfaces, the Greeks line their amphorae with resin. This preserved wine for use in commerce. The Romans took a step forward when they invented wooden barrels. They could be stoppered better than amphorae, and the oak imparted flavor from the wine. Some Roman wines apparently kept very well. There are reports of vintages that lasted to a hundred years.
Grape Juice and Wine