The sour orange is native to southeastern Asia. Usually too sour to be enjoyed out of hand, sour oranges are often used in the production of marmalade, jellies, jams and liqueurs. Also known as the “bitter orange,” the most common varieties include the Bergamont or Seville. The essential oils of these oranges are often used to flavor candy, baked goods, gelatins, chewing gum, soft drinks and many pharmaceutical products. The peel is also dried and used to flavor teas, such as Earl Grey.