Red wine. View of a bottle and glass of red wine. Wine is an alcoholic drink usually made from fermented grape pulp. Red wine is made by using the grape skin as well as the pulp in the fermentation process. The sugar content is converted to alcohol by the yeast which lives on the skin of the grape. Most wines have an alcohol content of 10-12%. It has been shown that a glass of wine a day reduces the risk of heart disease. Prolonged excessive alcohol consumption, however, can lead to addiction, chronic liver damage, and ultimately death.