Birch beer is a carbonated soft drink made from herbal extracts, usually from birch bark. It has a taste similar to rootbeer. 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, purple and clear (often called white birch beer), 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. In the dairy country of southeastern and central Pennsylvania, an ice cream soda made with vanilla ice cream and birch beer is called a Birch Beer float, while chocolate ice cream and birch beer makes a Black Cow. Alcoholic birch beer, in which the birch sap is fermented rather than reduced to an oil, has been known in the region from at least the mid-nineteenth century. This drink is most commonly found in the Northeastern US and Newfoundland in Canada.