Kumquats: Sweet-tarts of the citrus rodeo

FRAGRANT: Nagami kumquats being harvested at Beck Grove in Fallbrook.
FRAGRANT: Nagami kumquats being harvested at Beck Grove in Fallbrook.
(David Karp / For the Times)

Growing up in Los Angeles in the 1960s, my brother and I knew just what to do with kumquats from the potted tree on the patio: We tossed them at each other. Like most Californians, we never ate them.

Kumquats do present a challenge for the uninitiated. In most citrus, the juicy pulp is consumed and the peel discarded. Kumquats, however, are eaten whole, and their appeal stems from the contrast between their tart flesh and thick, sweet rind.

But maybe folks are finally catching on. Without much fanfare, more and more kumquats are being grown in California, which now leads the nation in production. Granted, it’s still a minor crop compared to other citrus, but chefs and home cooks alike are giving kumquats more respect, and specialty growers are planting intriguing, previously rare varieties.

Kumquats are intense, complex flavor bombs. Trained sensory analysts detect a fresh, citrusy odor and pungent taste to begin, followed by green and woody notes, with a persistent oily undertone and a sweet, apricot-like aftertaste. A few years ago, a Korean flavor chemist determined that the component that imparts the fruit’s distinctive spicy aroma is an ester, present in minute quantities, called citronellyl acetate.

Northern San Diego County, where many farms focus on specialty crops, is the nation’s top production area, with 71 acres of kumquats, mostly in small plantings. The local season starts in January and runs through June, but kumquats are at their best, fully ripe yet still firm, from now through April.

The fruit’s biggest booster may be Helene Beck of Fallbrook, a.k.a. “Miss Kumquat,” who grows several hundred of the trees with her husband, Robert. She sells kumquats wholesale and online, along with kumquat syrup, purée, conserves and fruit leather, and is working on a book of recipes.

“Even here in Fallbrook, many people still don’t know what to do with them,” she says, offering a plate of freshly baked kumquat cookies.

The view from her Tuscan-style hilltop villa, flanked by cypress trees, evokes an old-world vineyard and chateau. Below in the kumquat orchard, the lush green trees sparkle with bright orange fruit, which two workers painstakingly clip into canvas sacks.

Chefs prize kumquats’ pungency, chewy texture and sheer beauty. Breanne Varela, pastry chef at Lucques and AOC, is planning a dessert of yogurt panna cotta served with candied kumquats, Cocktail grapefruit and blood oranges. Zoe Nathan at Rustic Canyon combines kumquats with crème fraîche for an ice cream that she serves by itself or with cornmeal pound cake.

Origin in Asia

Kumquats are native to China, where they are eaten fresh, made into preserves, used for religious offerings and grown as ornamental plants. They are popularly considered citrus -- and were even first classified as members of the Citrus genus after the Scottish botanist Robert Fortune brought the first kumquat plant to Europe in 1846. But in 1915, the great scientist Walter T. Swingle established a new genus, Fortunella, for kumquats, based on structural differences in their flowers, leaves and fruits, compared with those of other Citrus.

Molecular sequence analyses, which in theory could determine how close kumquats are to Citrus genetically, have differed in their conclusions, depending on the methods used. A British botanist, David J. Mabberley, proposed reuniting kumquats taxonomically with Citrus in 1998, but Swingle’s system is still more generally accepted among scientists, at least partly because they don’t want the inconvenience and confusion of changing names.

Kumquats arrived in California about 1880, long after other citrus, and for many years, Florida dominated production, primarily in the gift-package trade; in California, kumquats were grown almost exclusively as ornamental plants. The 1950 census listed 180 acres of kumquats in Florida, just one in California. But starting in the late 1960s, increased Asian immigration to California spurred demand and prices for kumquats.

“The market was so hot for [kumquats] in the ‘80s, we used to send crews to harvest home garden trees,” recalls Lloyd Bittner, manager of the Cal Flavor packing house in Escondido, which was at the center of the boom.

Eventually, supply exceeded demand, Bittner says. “People would call up to ask, ‘Hey, are you coming to pick my kumquats this year?’ But we had all that we could sell.”

Today, California has 133 acres of kumquats, and Florida has 46, mostly near Dade City, northeast of Tampa. Shippers estimate that 80% of the crop goes to Asian Americans, and that 90% is the standard oval Nagami variety, with bright orange, spicy-sweet skin and tart pulp.

In the last decade, however, the roundish Meiwa variety, the best for eating fresh, has become more available. Introduced from Japan about 1910, after the Nagami variety, it is larger, with a thicker, sweeter skin, and the juice is less sour; when fully ripe it can have a wonderful tropical banana flavor.

Long popular in home gardens, it had not been planted much commercially because of its slower, less vigorous growth, incompatibility with some common rootstocks and the shorter shelf life of its fruit.

These drawbacks sound daunting, but in De Luz, a gorgeous, pristine area of citrus and avocado groves and chaparral north of Fallbrook, two growers, Juan Garcia and George Cunningham, have thrived planting Meiwas. “I sell 10-pound boxes of Nagami for $22, but Meiwa for $31,” Cunningham says. “Meiwas just fly out of here.”

Normally, other farmers would jump at such a lucrative opportunity, but citrus growers in San Diego County have suffered such catastrophic ordeals recently -- fires, irrigation water cutbacks and the threat of deadly greening disease -- that few are planting new citrus these days.

In the southeastern San Joaquin Valley, the state’s largest commercial citrus district, kumquats are rare, but several niche growers offer exotic kumquats and hybrids.

The most potentially significant, although planted in only small quantities so far, is the Nordmann Seedless. It was discovered by George Otto Nordmann on a Nagami seedling in DeLand, Fla., in 1965. With a teardrop shape and a slightly thinner, paler skin (probably caused by the absence of plant hormones from the seeds), it looks a little different from the Nagami but has much the same flavor. Its primary appeal is its lack of seeds.

That’s right, a seedless kumquat. For anyone who has ever grappled with a large batch of the fruit, that is major news. Tiny as they are, kumquats typically have two to five seeds, and removing them is tedious. D.J. Olsen, chef of wine bar Lou in Hollywood, which serves sliced candied Meiwas from Garcia with burrata, speck and vincotto, says his kitchen help groans when he brings in a box of kumquats for de-seeding. “They say, ‘I did it last time, so it’s your turn,’ ” he says. After tasting a Nordmann recently at the Santa Monica Farmers Market, Olsen said: “I’d buy that in a heartbeat.”

Other seedless varieties exist in Texas and Asia, and it seems likely that in time, they will become common.

Kumquats ripen peculiarly late in the San Joaquin Valley -- as late as March in some locations. To supply the market for Chinese New Year, which can fall from late January to mid-February, several growers have planted Fukushu, which is large, round and juicy, and matures around Christmas. It is sold as a kumquat but is actually a hybrid with mandarin.

“Asians love them, and marmalade companies get into bidding wars for them,” says Mike Foskett of California Citrus Specialties, who has 300 Fukushu trees.

The calamondin

Another kumquat-mandarin hybrid starting to be grown commercially is the calamondin, the national citrus fruit of the Philippines, where the juice is used for souring, like limes or lemons.

Filipino immigrants to California have long grown the attractive trees in their gardens and sold some of the fruit at farmers markets, but not in substantial quantities.

Brigitte and Angelito Uson, taking the cake for creative siting, planted 175 calamondin (or kalamansi) trees to beautify a bare corner of the lot around their funeral home, Vaca Hills Chapel, in Vacaville, Calif., southwest of Sacramento.

They did so well selling the fruit to Filipino stores in the San Francisco area that they planted nearly 4,000 trees on 10 acres in nearby Fairfield. Filipinos squeeze fresh calamondin juice into marinades for barbecue meats and add it to soy sauce to dress noodles, while the rind, which has a kumquat aroma, is used to flavor custards, Angelito Uson says.

Kumquats and their kin may remain too perplexing to make it into the big leagues of produce, but their idiosyncrasy at least has earned them a niche more dignified than puerile projectiles.