Birch beer in its most common form is a carbonated soft drink made from herbal extracts, usually from birch bark, although in the colonial era birch beer was made with herbal extracts of oak bark. It has a taste similar to root beer. There are dozens of brands of birch beer available.
Various types of birch beer made from birch sap are available as well, distinguished by colour. The colour depends on the species of birch tree from which the sap is extracted (though enhancements via artificial colouring are common presently). Popular colours include brown, red, blue and clear (often called white birch beer), though others are possible. This drink is most commonly found in the Northeastern United States, and Newfoundland in Canada. 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 flavour, reminiscent of teaberry. 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 from at least the seventeenth century. The following recipe is from 1676:
To every Gallon whereof, add a pound of refined Sugar, and boil it about a quarter or half an hour; then set it to cool, and add a very little Yeast to it, and it will ferment, and thereby purge itself from that little dross the Liquor and Sugar can yield: then put it in a Barrel, and add thereto a small proportion of Cinnamon and Mace bruised, about half an ounce of both to ten Gallons; then stop it very close, and about a month after bottle it; and in a few days you will have a most delicate brisk Wine of a flavour like unto Rhenish. Its Spirits are so volatile, that they are apt to break the Bottles, unless placed in a Refrigeratory, and when poured out, it gives a white head in the Glass. This Liquor is not of long duration, unless preserved very cool. Ale brewed of this Juice or Sap, is esteem’d very wholesome.