Traditional ginger beer is a sweetened and carbonated, usually non-alcoholic beverage. Historically it was produced by the natural fermentation of prepared ginger spice, yeast and sugar.
Current ginger beers are often manufactured rather than brewed, frequently with flavor and color additives, with artificial carbonation. Ginger ales are not brewed.
Ginger beer's origins date from the colonial spice trade with the Orient and the sugar-producing islands of the Caribbean. It was popular in Britain and its colonies from the 18th century. Other spices were variously added and any alcohol content was limited to 2% by excise tax laws in 1855. Few brewers have maintained an alcoholic product.
Ginger beer is still produced at home using a symbiotic colony of yeast and a Lactobacillus (bacteria) known as a "ginger beer plant" or from a "ginger bug" starter created from fermenting ginger, sugar, and water.