Root beer is a carbonated, sweetened beverage, originally made using the root of the sassafras plant (or the bark of a sassafras tree) as the primary flavor. Root beer, popularized in North America, comes in two forms: alcoholic and soft drink. The historical root beer was analogous to small beer in that the process provided a drink with a very low alcohol content. Although roots are used as the source of many soft drinks throughout the world, often different names are used.
Although most mainstream brands are caffeine-free, there are some brands and varieties that contain caffeine.
Homemade root beer is usually made from concentrate, though it can also be made from actual herbs and roots. Both alcoholic and non-alcoholic root beers have a thick and foamy head when poured, often enhanced by the addition of yucca extract. The flavor varies widely between brands and methods--from insipid and insignificant to a bold, rambunctious brew which lingers in the back of the throat and pleasantly makes itself manifest even in the nasal passageways, a hallmark of only the rootiest root beers. The discontinuation of the use of sassafrass root is thought by some to make the difference here.
The custom of brewing root beer goes back to the 18th century. Farm owners used to brew their own (then) light-alcoholic beverage for family get-togethers and other social events. During the 19th century, some pharmacists tried to sell their version of root beer as a miracle drug.
In 1876, pharmacist Charles Hires first introduced a commercial version at the Philadelphia Centennial Exhibition. Hires was a teetotaler who wanted to call the beverage "root tea." However, his desire to market the product to Pennsylvania coal miners caused him to call his product "root beer" instead. By 1893, root beer was sold as a bottled soft drink to the public. Especially during Prohibition, non-alcoholic versions proved to be commercially successful.
In 1960, a key ingredient (the sassafras root) came to be known as a carcinogen and its use was banned by the U.S. Food and Drug Administration. Following this ban, companies began experimentation with artificial flavors and preparation techniques to remove the unhealthy effects of root beer while preserving its flavor.
Sassafras albidum – Sassafras (roots) – safrole. The oil from these roots is believed to be carcinogenic[vague] so artificial versions are generally used instead. However, natural extracts with the safrole distilled and removed are available.