No viticultural subject has generated such diverse opinions as the relation of the vine to its environment and to the composition and quality of the resulting musts and wines… The interrelation of climate, geography, and the variety of grape determines the potential for fruit and wine quality. Man, of course, can influence it by pruning, training, irrigation, fertilization, cultivation, time of harvest, sugaring, control of fermentation, and aging. These factors vary from year to year, from region to region, and from variety to variety. But most enologists agree that climate has the greatest influence on wine quality… Over and above climatic variables, there may be specific geographical conditions that influence grape maturity and wine quality.
(Amerine and Wagner, 1984:97, 118)
True wine is the fermented juice of grapes, although the term is frequently applied less correctly to the products of other fruits. In Lichine's (1981:38) words, 'properly wine comes from grapes and nothing else-and it is the natural product of grapes which have been gathered, carted to the wine shed, pressed, and left in vats until the grape sugar has fermented into alcohol'. Three separate stages are involved in making wine: viticulture, the cultivation of grapes; vinification, the process whereby these grapes are turned into wine through the fermentation of grape sugar into alcohol; and then the maturation and development of wine into a product that is ready to be consumed or sold. In order to understand the changes that have taken place in viticulture and the wine trade it is essential to grasp the central characteristics of these processes, and this chapter therefore provides a basic overview of each in turn.
The physical properties of the vine, and the biochemistry and microbiology of wine making have played a fundamental role in