Oranges can be divided into two broad categories: sweet oranges and bitter oranges.
Sweet oranges have a sweet and juicy flesh and are found in both savory and sweet dishes. They are eaten out of hand, as a breakfast fruit, snack, or dessert. They can be sectioned and served in fruit salads or compotes, chicken or turkey salads, or as a topping for tarts. The grated rind or juice of sweet oranges is used to flavor soufflés, sauces, glazes or creams, mousses, and sorbets.
Bitter or sour oranges have a dry flesh that is too bitter for eating for eating out of hand. But the peel of the bitter orange is aromatic and flavorful and can be used to makes marmalades, candies, sauces, syrups and liqueurs.
The sweet oranges’ distinctive flavor is a blend of sugar and acid. Sweet oranges are round to oval in shape and can be further divided into three groups: navel, common, and blood oranges.
The bitter orange is said to be an ancestor of the sweet orange. Bitter oranges are not for eating out of hand.
Sweet oranges–navel, common, and blood–and bitter oranges:
• Navel oranges have thick, rough, bright orange skins that are easy to peel. They are large and seedless with a rich, juicy flavor, and their segments are easy to separate. Sweet oranges develop a small second fruit within the larger fruit at the blossom end of the orange. Where the second fruit develops is an indentation that looks like a human navel and thus the name. The Washington navel orange is the original and best known navel orange. Other navel orange varieties are Cara Cara, Fukumoto, Lane Late, Robertson, Skaggs Bonanza, and Spring. The peak harvest for navel oranges is from mid-winter through early spring.
• Common oranges are round or slightly oval and medium-sized with a thin, smooth rind. They have a sweet-acid flavor and are juicier than navel oranges. Common oranges also have more seeds and are more difficult to peel than navel oranges. Common oranges are sold fresh for eating out of hand, but more importantly almost all orange juice is squeezed from common oranges. The Valencia orange—the most popular orange in the world—is a common orange. Other common orange varieties include Trovita, Hamlin, Jaffa, Marrs, Parson Brown, and Pineapple. The peak harvest for common oranges is from late spring to mid summer.
• Blood oranges are similar in size to common oranges but with a red blush skin and a streaked to full scarlet, crimson, or purple flesh. The blood orange is juicy and has a sweet-tart taste that is rich, flavorful and often hints of berry. Blood oranges are popular for eating out of hand, juicing, and as garnishes for sweet and savory dishes.The best known blood orange varieties are Sanguinello, Moro, and Tarocco. The peak harvest for blood oranges is from early winter to early spring.
• Bitter or sour oranges usually have a thick, dimpled, deep-orange colored peel, and a sometimes pithy flesh. Bitter oranges are usually not eaten fresh because the flesh is too tart and bitter tasting. The sour flavor of these oranges is a result of the fruits’ acidic juices; the bitter is due to its essential oils. The peel and juice of sour oranges are used to make marmalades, candies, sauces, syrups, pies, flavorings, and liqueurs. The best known sour oranges are Seville, Bouquet de Fleurs (also called Bouquet), Chinotto, and Bergamot. Sour oranges are harvested beginning in late fall and the harvest continues through spring depending upon the region and climate.
Sour oranges are higher in natural pectin—a gelling agent—than sweet oranges. That makes them ideal for use in marmalades, jellies, and preserves.
The botanical name for the sweet orange is Citrus sinensis. The botanical name for the bitter orange is Citrus aurantium.