kumquat (French), Kumquat (German), fortunella/kumdvatti (Finnish), jin ju (Chinese), kinkan (Japanese)
Until recently, this member of the citrus family has always been placed with the orange in the genus Citrus. It has now been assigned a genus of its own because of the simpler structure of its fruits.
The golden rind of the kumquat is not a distinct pithy covering like that of a true citrus fruit; but, rather, it is soft, thin, and pulpy, making it edible along with the pulp. The kumquat can also form hybrids with true Citrus species.
Growers have experimented with Fortunella x Citrus hybrids, resulting in orangequats and limequats. Fortunella x Poncirus (a trifolate orange) produced hybrids called citrangequats. One such is the Thomasville, which has smallish golden fruits and a good flavour.
The genus Fortunella, included in with true citrus fruit trees, was created by Dr. Walter T. Swingle in 1915 and named for Robert Fortune, a noted plant explorer of the British Royal Horticultural Society, who had introduced them into London from China in 1846. By 1855, kumquats had arrived in Florida from Japan.
Their name comes from the Cantonese kam kwat, meaning “golden orange”. The Chinese name means “give friend gift” and comes from the custom of giving the potted plants as gifts.
In China, as well as western countries, the plants, along with their fruits, were often placed on the table at fashionable dinners for the guests to pick their own fresh fruits for dessert.
Kumquat trees are native to South East China, but are now grown in many parts of the world. The species most often cultivated is the oval-shaped Fortunella margarita (Nagami), but the round F. japonica (Meiwa) has larger sweeter fruits. Nagami is the most popular kumquat grown in Florida, but most people prefer the sweeter Meiwa.
Resembling tiny oranges, these small, elongated fruits are about the size and shape of a large olive. The thin rind can be pebbly or smooth, encasing three to five segments of fruit that is not as juicy as citrus fruits.
Kumquats can vary in colour, ranging from orange, yellowish-orange, or reddish orange. While the rind is sweet, the flesh is very sour; but if the two are eaten together, they provide an explosive, blended sensation.
They can be eaten raw or cooked in a variety of dishes, or made into delicious jams and marmalades.
The most popular way of treating kumquats in China has been to preserve them in honey or, more recently, sugar.
Unfortunately, because kumquats are more susceptible than other fruits to the Mediterranean fruit fly, their importation is occasionally banned; therefore, their appearance on the market can be sporadic.
Kumquats are low in calories, but high in Vitamin C and fiber (if you eat skin and seeds, too). They also contain folate, riboflavin, and thiamin. They are full of phytochemicals and loaded with antioxidants and flavonoids.
Some of the best varieties of Kumquat include the following:
Hong Kong (F. hindsi), as its name suggests, is a species that grows wild in Hong Kong and in several provinces of China during the winter months. It is the smallest of true citrus fruits, growing only to the size of a pea to be known as the “Golden Bean”. Documents from the writings of Han Yenchin in 1178 describe this fruit as being “chin chu”. Its most distinctive characteristics are its brilliant orange colour and small size. The fruit is protected by many sharp thorns, which are much longer than the fruit itself.
Long Fruit (F. margarita) is a small delicate fruit resembling the Eustis with its small oval shape and seedy flesh. The smooth rind has a sunshine yellow colour and a distinctive oil. It also has a pleasant, but complex, combination of acidy spiciness and sweetness. It is of the same species as the Nagami.
Malayan (F. polyandra) is commonly cultivated in the Malay Peninsula, where it is known as a hedge lime because of its limelike flavour. Researchers have long thought that this fruit may be a limequat, and many sources question its validity as a kumquat. Its rind is a deep gold-orange colour that contrasts with the flame colour of the flesh. It is also large compared to other kumquats, and can have as many as eight seeds. Native to the tropical region of Malaysia, it can also be found in southern China.
Meiwa (F. crassifolia) is a cross between F. margarita x F. japonica which resulted in a larger, rounder, plumper fruit with a lemon hue and tart flesh. Its golden rind is smooth and tender and as sweet as candy. It is both pleasing to eat and prized as an ornamental. The Meiwa originated in China but is grown extensively in Japan where it is known as the “Neiha Kinkan”. The Meiwa is the best kumquat for fresh eating as the rind can be consumed along with the flesh. It does lack juice but has very few seeds.
Nagami (F. margarita) is the most popular kumquat grown in Florida. When eaten whole, it has a strong, sweet start, but a slightly bitter finish. It is a vigorous and prolific fruit, with an oval shape and a smooth, bright orange rind. The spongy interior is heavy with juice and has some cotyledons. The plant’s symmetrical green foliage and abundant stunning fruit make it a remarkable ornamental.
Limequats are, as the name suggests, a cross between a lime and a kumquat which produced a fruit with a bright green skin. The skins are edible but extremely sour, so it is difficult to eat them raw. They are best used cooked or preserved like kumquats and served in a similar manner.