Birch beer is a carbonate soft drink made from herbal extracts, usually from birch bark. It has a taste similar to yet distinct from root beer, sweeter with a slightly minty and sharper flavor. Various types of birch beer are available, distinguished by color. The color depends on the species of birch tree from which the sap is extracted (though enhancements via artificial coloring are not uncommon). Popular colors include brown, red, and white (clear), though others are possible. After the sap is collected, it is distilled to make birch oil. The oil is added to the carbonated drink to give it the distinctive flavor. "Black birch" is the most common source of extract.