Bitter oranges, sometimes also known as Seville oranges or sour oranges, are a citrus fruit that is a hybrid of mandarin oranges and pomelo, or grapefruit. They have thick, yellow-orange skin, and their flesh is extremely sour and bitter. Though the raw fruit itself is not usually eaten, their juice, rind, and zest are used in various cuisines around the world.
What Are Bitter Oranges?
Bitter oranges are a citrus fruit of the species Citrus aurantium, which is itself a cross between the pomelo (Citrus maxima), or Duncan grapefruit, and the mandarin (Citrus reticulata).
Bitter oranges are the favored oranges for making classic British marmalade because they have a high pectin content, which helps to set the marmalade, and because their rather intense sourness helps to balance out the large amount of sugar used for making marmalade. Apart from this, however, they are usually used more as a seasoning than as an actual fruit. But they excel in this regard. The juice of bitter oranges is a superb acid for adding to savory dishes. And while their sourness is their most notable characteristic, they impart a greater range of flavor than lemons or limes, making them an excellent addition to cocktail and salad dressing recipes.
Bitter oranges are small fruits, usually measuring about 3 inches in diameter and weighing 5 to 6 ounces. Their skin is rough and dimpled, with a thick rind and yellow-orange color. The fruit itself is yellow to orange and juicy, consisting of around 10 segments of flesh along with a large number of oblong, white seeds. They are only available for a short time during the winter, starting in December (in the northern hemisphere) and ending in early February.
How to Use Bitter Oranges
Because of their intensely sour flavor, bitter oranges are almost never eaten in their raw form, but rather, it's their juice, their peel, and their zest that is most commonly utilized. Their juice is used in sauces, marinades, and desserts, and is popular in Spanish, Moroccan, Iranian, Mexican, Cuban, and other Latin American cuisines, as well as some East Asian cuisines. Its zest is extremely aromatic and can be used in a variety of sweet and savory dishes, as well as for making bitters. Even the peel of a bitter orange can be simmered in a sugar syrup to make candied peel.
What Do They Taste Like?
Bitter oranges have a pronounced sour flavor and slight bitterness along with very little sweetness. If you imagine concentrating the intense, aromatic flavor of oranges, retaining the acidity and juiciness, but replacing the sweetness with sourness, you begin to get the idea of what bitter oranges taste like.
A 100-gram serving of bitter oranges provides 37 to 66 calories and 10 to 15 grams of carbs, along with less than half a gram of fiber, around 1 gram of protein, and negligible fat. It also provides 45 to 90 milligrams of vitamin C, which is from 50 to 100 percent of the USDA daily value.
Bitter Orange Recipes
Bitter orange is a staple ingredient of various cuisines, and it can be used in the place of other citrus fruits in a number of dishes.
Where to Buy Bitter Oranges
Bitter oranges are not the easiest fruit to find. During the winter, you might find them at specialty food stores like Whole Foods, sometimes sold as "sour" oranges rather than "bitter."
If you live near a Latin American grocery or supermarket, or a Cuban grocery store, in particular, it's possible that you might find them there as well. Additionally, some of these Latin American groceries might also carry bottled bitter orange juice. Moroccan, Spanish, and Iranian cuisines use bitter orange quite a lot, so those are some other possibilities, depending on what sort of retail outlets there are near you. The bottled juice, sold by Goya, might also be available online.
Finally, if you can't find it at all, you could try combining equal parts orange and lime juice, with perhaps a splash of vinegar added to get the acidity right.
Bitter oranges should be kept in a dry place in cool or cold temperatures. You can keep them at room temperature for a day or two, but if you need to store them for longer than that, keep them in the crisper drawer of your refrigerator on the low humidity setting (i.e. with the vent all the way open), where they'll stay fresh for three to four weeks.
Morton J. Sour Orange. Horticulture and Landscape Architecture, Purdue University