Wine is an alcoholic drink made from fermented fruit.
Yeast consumes the sugar in the fruits and converts it to ethanol and
carbon dioxide, releasing heat in the process. Though wine can be made
from a variety of fruit crops such as plum, cherry, pomegranate,
blueberry, currant and elderberry, it is most often made from grapes,
and the term "wine"
generally refers to grape wine when used without a qualifier.
Different varieties of grapes and strains of yeasts are major
factors in different styles of wine. These differences result from the
complex interactions between the
biochemical development of the grape, the reactions
involved in fermentation, the grape's growing environment
(terroir), and the wine production process. Many countries
enact legal appellations intended to define styles and qualities of
wine. These typically restrict the geographical origin and permitted
varieties of grapes, as well as other aspects of wine production.