<P> Ingredients in early and traditional root beers include allspice, birch bark, coriander, juniper, ginger, wintergreen, hops, burdock root, dandelion root, spikenard, pipsissewa, guaiacum chips, sarsaparilla, spicewood, wild cherry bark, yellow dock, prickly ash bark, sassafras root, vanilla beans, dog grass, molasses, and licorice . Many of these ingredients are still used in traditional and commercially produced root beer today, which is often thickened, foamed, or carbonated . Although most mainstream brands are caffeine - free, Barq's does contain caffeine . </P> <P> Root beer can be made at home with processed extract obtained from a factory, or it can also be made from herbs and roots that have not yet been processed . Alcoholic and non-alcoholic traditional root beers make a thick and foamy head when poured, often enhanced by the addition of yucca extract, soybean protein, or other thickeners . </P> <Ul> <Li> Sassafras albidum--sassafras roots and bark containing the aromatic oil safrole (or an artificial substitute) </Li> <Li> Smilax regelii--sarsaparilla </Li> <Li> Smilax glyciphylla--sweet sarsaparilla </Li> <Li> Piper auritum--root beer plant or hoja santa </Li> <Li> Glycyrrhiza glabra--liquorice (root) </Li> <Li> Aralia nudicaulis--wild sarsaparilla or "rabbit root" </Li> <Li> Gaultheria procumbens--wintergreen (leaves and berries) </Li> <Li> Betula lenta--sweet birch (sap / syrup / resin) </Li> <Li> Betula nigra--black birch (sap / syrup / resin) </Li> <Li> Prunus serotina--black cherry </Li> <Li> Picea rubens--red spruce </Li> <Li> Picea mariana--black spruce </Li> <Li> Picea sitchensis--Sitka spruce </Li> <Li> Arctium lappa--burdock (root) </Li> <Li> Taraxacum officinale--dandelion (root) </Li> </Ul> <Li> Sassafras albidum--sassafras roots and bark containing the aromatic oil safrole (or an artificial substitute) </Li>

What kind of root is in root beer