Of the four main species of kumquat, the nagami kumquat has the distinction of being the sourer of the two most prevalently grown in the United States. With a thin, sweet rind that is eaten along with the rest of the sourer flesh, this citrus fruit from the plant Fortunella margarita is like no other. It has the color and texture of an orange, the size and shape of a fat olive, and a taste all its own.
Also known as the oval kumquat, in 1885 the nagami kumquat was brought to the southern regions of the United States from its home in Japan. The city of Saint Joseph, Florida, considers itself the kumquat capital of the country. In 2011, however, this fruit's hardy tree is cultivated from Florida through Texas and out to California. The other commonly grown variety in North America is the meiwa kumquat, or Fortunella cressifolia, which has a plumper, cherry-tomato shape and a sweeter flavor than the nagami species.
All of these plants owe their name to the 19th century Scottish botanist Robert Fortune. Though China and Japan had cultivated the nagami kumquat and other species of this citrus tree for a few centuries before, Fortune placed them on the official biological record. He is credited with introducing them to a broader audience throughout Europe and then North America.
The other predominant varieties of kumquat found throughout the world are typically grown in Asia. The marumi, or Fortunella japonica, is perhaps the most prized in culinary circles with a round shape and more subdued flavor. It can often be found in North American markets more prevalently than the locally grown meiwa variety. The Hong Kong Wild species, or Fortunella hindsii, is grown and consumed primarily in China. These two Asian varieties are also suitable for being pruned into miniature bonzai trees.
A nagami kumquat can be used as an ingredient in just as many ways as other citrus fruits like oranges, grapefruit, lemons and limes — perhaps even more due to its edible rind. Recipes for desserts predominate, from kumquat cake or pudding to cheesecake or sorbet. It is also sliced into aesthetically pleasing slivers and added to fruit salad. Chefs know, however, that citrus like the nagami kumquat can also be paired to fine effect with certain savory meals, particularly proteins like chicken or fish. Providing both sweet and sour, it is also an expedient way to satisfy two of the five flavor requirements of the Japanese culinary objective known as umami, which means "deliciousness."
