Dried bitter orange peel.
Bitter oranges are members of the orange family that are grown for their intensely sour and bitter fruits and fragrant peels. While bitter orange is rarely used as a standalone item in food, products from the fruit are integrated into things as varied as tea and jam. Like many other citrus fruits, bitter oranges prefer semi-tropical climates and tend not to thrive in cooler areas, although they are sometimes grown ornamentally in temperate zones. Bitter oranges are rarely available for sale in markets, although products such as bitter orange extract are sometimes sold.
Bitter orange peel is used to make triple sec, a classic ingredient in Cosmopolitans.
Alternative names for bitter orange include sour orange and Seville orange, named after a Spanish city in southern Spain. A variant of bitter orange, the bergamot orange, is actually a subspecies of Citrus aurantium, the botanical classification for bitter orange. In any case, bitter oranges are characterized by an intensely bitter pulp that is generally considered unpleasant on its own. The citrus fruit appears to have originated in Vietnam, where spiny evergreen trees have been cultivated for hundreds of years.
Bitter oranges have an intensely flavored rind.
In Asian cuisine, the bitter taste is valued as a food supplement. Bitter oranges are often preserved for use as a garnish. Outside of Asia, bitter oranges are cultivated for use as a botanical extract. Bitter orange oil is often used in cosmetics and is sometimes included in health supplements as well. The peels and fruits can be candied for inclusion in sweets and desserts, and the sour pulp is added to jam and other preserves for a shot of tart flavor. Bitter orange extract is also a crucial ingredient in triple sec and Curaçao, two classic liqueurs.
Bitter oranges are sometimes used to flavor tea.
The bergamot orange is a variant cultivated in Italy for its flavorful and spicy peels. Bergamot is a classic ingredient in Earl Gray tea and is also used in other foods. The fruit of the bergamot orange has a distinctive pear shape that differentiates it from bitter oranges. A true bitter orange has a flattened shape.
The bitter orange tree is famous for being very hardy, which is why it is sometimes used as a rootstock. When bitter oranges are used as rootstocks, they are pruned back to a single trunk, allowing gardeners to graft another variety of orange onto the trunk. Bitter orange rootstock can resist cold, poor water, and insect invasion more effectively than some more palatable orange species, making it a good choice for citrus trees intended for beginning gardeners.