VITICULTURE

Vine-cultivation or ylticulture is a specialised type of t1orticulture. The vine is a delicate plant cultivated in a few parts of the globe. For the grapes to ripen and the juice to be concentrated, a mean summer temperature of about 18°C is required. .Prolonged droughts are harmful to the vines because of excessive evaporation and the lack of ground moisture. Vines like plenty of sunshine and, near the limits of their cultivation, they are grown on south-facing slopes. A moderate rainfall of about 760 to 1,000 mm chiefly in the winter months is required. The Mediterranean climate with its sunny summer and warm, wet winters is thus ideal for viticulture. Vine does well in fairly deep, well-drained soils. Calcareous soils, such as those on the .chalk or limestone uplands of France and Germany, produce some of the best-known wines in the world.

After the grapes have been picked, juice is extracted and femientation takes place when the sugar in the juice reacts with the yeast present in the bloom of the grape-skin. This fermentation is allowed to. continue for several days until the liquid becomes 'quite clear. After a. second fermentation, there is no more carbon dioxide left in the casks. The resultant wine is 'still' rather than sparkling. The wine is bottled and then stored.
The colour of the wine is decided by the colour of the grapes, by the'soil in which they were grown, and by blending. Elurgundy and Bordeaux wines are mostly red, Rhine and Moselle wines are white, and rose-pink wines come chiefly from the Loire valley. Dry wines are fully fermented; sweet wines are only partially fermented so that not all the sugar is converted into alcohol.

Most of the world's wine comes from the Mediterranean countries. Italy and France are the greatest wine producers and also the greatest consumers. France is a major exporter but is a net importer of wine. High grade wines like Sherry (Spain), Asti and Chianti (Italy) or Port (Portugal) enter the international market and are in good demand.