Excerpted from The Wild Blueberry Book By Virginia M. Wright. Down East Books, Camden, Maine; hardcover; 82 pages; $14.95. DownEast.com

She was a New Yorker on her first trip to Maine, and I couldn’t help but eavesdrop as she perused the produce at a midcoast farm stand. In her hands she cradled a green quart box brimming with dusky blueberries. “Ooooo, look at these baby berries!” she cooed, gently nudging the fruit. “Look how tiny they are! Aren’t they sweet?”

Sweet they are, I wanted to tell her, and tart, too, but they are not, as she presumed, “baby,” or immature, versions of the familiar marble-sized blueberries grown in New Jersey, Michigan, and other places around the world. They are wild blueberries, an ancient species (Vaccinium angustifolium) that took root in North America as the glaciers receded ten thousand years ago and thrived in the sandy, acidic soils that other plants found inhospitable. Naturally growing stands of wild, or lowbush, blueberries are commercially harvested only in Maine and eastern Canada, and fresh ones are almost impossible to find in markets south of New England.

Grazing on them in roadside patches and on granite hilltops is a mid-summer rite in these parts. Each berry bursts with its own flavor. The first may be sweet, the second tart. One may be grapey, another citrus-y. Some are intense. Others are subtle. As you pluck your way through a mass of the low-growing shrubs, you begin to associate tastes with colors: maybe the indigo ones are sugary, the black ones piquant, the turquoise ones tangy. Pop a handful into your mouth and you get a jammy fusion of flavors (purple lips and purple teeth, too). Pour a couple of cups of them into a piecrust, and the filling bakes and oozes into something deep, intricate, and just plain wonderful.

There’s a reason wild blueberries from one bush taste different from those of its neighbor: They are different. One acre of wild blueberries typically contains well over one hundred varieties of the berry, each one as genetically distinct from the other as a McIntosh apple is from a Delicious. The shin-high plants mingle as they grow, spreading underground by way of a shallow rhizome root system. “That rich genetic diversity is what gives wild blueberries their unique flavor,” says David Yarborough, a wild blueberry specialist with the University of Maine Cooperative Extension. “You also get a mix of overripe and underripe fruit along with fruit that’s perfectly mature, which adds to the complexity of their taste.” He estimates that there are 6.5 million distinct wild blueberry clones in Maine alone.

By contrast, there are just slightly more than one hundred varieties of the cultivated, or highbush, blueberry species, and since a grower is likely to plant only one or two of them, his field yields berries that are uniform in size, color, and flavor. Larger, sturdier, and easier to pick than wild blueberries, highbush berries are the variety you’re most likely to find in the supermarket produce section. But if you relish fruit for its flavor, not ease of harvest, you’ll find the cultivated globes, while tasty, can’t compete with the tart, distinctive flavor of wild blueberries.

The Potent Quotient
The Japanese have become enthusiastic consumers of wild blueberries since their healthy antioxidant properties were discovered about fifteen years ago. They wolf down blueberry pasta, blueberry pizza, and blueberry curry, along with many of the same products westerners enjoy.

“Blueberry jam is the second most popular jam in Japan,” reveals Ed Flanagan, CEO and president of Jasper Wyman & Sons, the world’s second largest grower and processor of wild blueberries. “Blueberry yogurt is also very popular.”

So, too, is blueberry wine, as University of Maine food scientist Mary Ellen Camire discovered. The professor received three complimentary bottles of the stuff from a New Jersey vintner who was convinced that her testimony in the Japanese edition of Men’s Health magazine had triggered a sales spike in the East Asian nation.

What did Camire say that proved so potent? “Blueberries are one of the best foods for older men with erectile problems,” she was quoted in the article, titled “The Sex for Life Diet.”

No one has directly studied blueberries’ effect on erections (“My assistant said that’s when he would quit,” Camire says, laughing), but the professor bases her conclusions on scientific research. “Viagra works by opening up the blood vessels, and we know from our work and the work of other labs that that’s exactly what blueberries do. If something opens up the blood flow in your fingers, it’s going to open it up in your other extremities.”

Wild Blueberry Country
One of the kitschiest landmarks on Route 1 in Maine is a giant, grin-provoking blue dome, part amusement park, part specialty shop, bubbling up from the earth in the Down East town of Columbia Falls. Laying claim to the title of “world’s largest blueberry” (though one might argue it better resembles a flying saucer for Smurfs), Wild Blueberry Land sits, appropriately enough, in the heart of the most concentrated collection of blueberry barrens in Maine. It is the playful invention of Marie and Del Emerson, who are as steeped in wild blueberry culture as any Washington County family gets.

Del Emerson spent fifty-six years at the University of Maine’s Blueberry Hill research farm in neighboring Jonesboro, thirty-five of them as manager, and he is the inventor, with son Zane, of the Emerson Harvester, a hand-pushed blueberry picker that can collect twenty-five pounds of berries in just thirty seconds.

Marie occupies a rather different niche in wild blueberry culture. The American Culinary Federation’s first woman Chef of the Year and Maine’s only certified research chef (an occupation that blends culinary arts with product research and development), she is a culinary and baking instructor at Washington County Community College in Calais. Not surprisingly, Marie is regularly called upon to judge food entries at the Machias Wild Blueberry Festival (the most unusual entry she ever sampled: baked lobster with blueberry and crabmeat stuffing). All that, and she is the queen of Wild Blueberry Land, too.

The bakery is the main attraction at Wild Blueberry Land, filling the shop with the aroma of cookies, muffins, scones, and pies. “Every pie is different because each one is homemade one at a time,” Marie says proudly. “The scones are fresh. The muffins are fresh. We do everything by hand, no machines.” The shop carries every sort of blueberry product imaginable — jellies, honey, cookbooks, souvenirs, and more.

Reminiscent of 1950s roadside architecture, Wild Blueberry Land is in fact a relatively new landmark. The Emersons built the blue monster themselves in 2000, spraying the plywood exterior with foam and sealing it with silicone. In the years since, they have continued to expand their blueberry world, scattering several large round buoys (painted blue, of course) around the parking lot and opening a small blueberry-themed miniature golf course. Marie hopes eventually to move Del’s winnowing and packing facility to the site. “This is my Disney World,” she says wryly, “This is a fantasy. It’s flowers and it’s beautiful and it’s play.”

Wild Blueberry Land, 1067 Route 1, Columbia Falls. 207-483-2583.

Q&A With Blueberry Raker Brian Francis

How long have you been raking blueberries?
I’ve been going to Maine at the end of July or early August as long as I can remember — ever since I was a child. I’m fifty now. My father used to have a crew in Sedgwick, near Blue Hill. We worked for a number of leaseholders there. In 1978 we migrated up to Columbia Falls.

Do the people from Big Cove travel together as crews?
People come as families. They load up their vans and off they go. In August, our whole town practically shuts down because everyone is down to Maine.

One of the parish priests even went to do mass on the blueberry fields because that’s where his congregation was. Recently some of our people have gotten into fishing, so a lot of people who would have gone to Maine in the past now stay home to fish.

Is raking on the barrens in Columbia Falls different than raking the fields on the midcoast?
In Sedgwick, there were all these boulders in our way. It wasn’t an easy place to rake. We had always heard about the flat fields and bumper crops around Cherryfield and Columbia Falls, and when we got there, it was like heaven. In Sedgwick, a good raker would average maybe thirty or forty boxes a day, whereas in Columbia Falls, it’s easy to average one hundred boxes. [Rakers are paid $2.25-$2.50 per box. A box holds twenty-five pounds of berries.]

What’s your average?
I average seventy-five boxes. My best day was 104 boxes.

Do you have a special technique?
Just steady. A lot of times you see people taking breaks for an hour or so. Those are the ones who aren’t that productive. As long as you’re steady, you do well,  and if you start early enough, you might reach your goal by 2 o’clock, and you can call it a day.

Does your back hurt after a day of raking?
Every muscle in your body hurts! On the first day, you tell yourself you’re not going to work too hard so you won’t be sore, but you always overdo it and you always get up the next day hurting all over.

Do you like it?
I love it. My love for it has a lot to do with nostalgia — I’ve been doing this since I was a kid. I love the social aspect of going to Maine and being in the camps. After hours, people gather around the campfire and have coffee and talk. I think it’s part of the inherent nomadic instincts of a native person.

What are the camps like?
The camps are in the middle of the barrens. They recently had hot water and showers installed. Back in the 1970s, we didn’t have those conveniences. They were just shacks. But we liked it. It was a real adventure. We brought a Coleman stove and bathed in a brook. We still stay in shacks, but they’re fancier shacks.

Is it the same crowd at the camp year after year?
Pretty much. I bring my family, and the people my wife works with bring their families. That’s one of the unique aspects: everybody takes their holidays to go work in Maine.

You mean they have full-time jobs and this is their vacation? Is that true for you, too?
Yes. I’m a television film producer. My wife is a social worker.

Really? Raking is what you do for fun?
Yeah, it is fun. And it kind of pays for the vacation.

Do your kids rake?
They just turned old enough to rake — our daughter is fifteen, and our son is twelve. They didn’t like it very much.

Did you like it when you were a kid?
Not at first. I remember the real hot days. I would follow my father around and sit down in his shadow for the shade.

Is mechanization threatening this way of life?
It is. I won’t say it’s imminent, but it’s coming. In 2010 the company brought in two mechanical harvesters for the first time, which left us with two fewer fields to do. So we do worry about it. Raking has become a tradition for our people. We all feel we belong in Maine, that we’re Mainers also. We spend so much time there. The fondest memories we have are there.

Blueberry Festivals
Many summer fairs give wild blueberries a nod with pie-baking and pie-eating contests, but two stand out for the way they celebrate blueberries as a way of life.

The Maine Wild Blueberry Festival, part of the Union Fair in the midcoast town of Union since 1959, begins with the coronotion of the Wild Blueberry Queen, who will then preside over eight days of events, including several baking contests, cooking demontrations, and entertainment. August 20 – 27. 207-785-3281. unionfair.org

The Machias Wild Blueberry Festival, created in 1975 by the Centre Street Congregational Church, draws 15,000 people to the Down East town of Machias every August. The signature event, a hilarious musical featuring an all-local cast, is not to be missed (this year it’s “Blueberry Fields Forever”). 207-255-6665. machiasblueberry.com

Inside the Packing Plant
After the Harvest

Winnow
Within twenty-four hours of harvest, the blueberries are delivered to the packer. These facilities vary in size, from small barn operations like Del Emerson’s in Addison to large factories like G.M. Allen & Son, Inc. in Orland and Jasper Wyman & Son in Cherryfield and Deblois. The berries are poured into a winnowing machine, which blows out the leaves and twigs.

Remove Rocks
The berries emerge from a winnower onto a rock eliminator, a large vibrating sifter that allows pebbles and debris to drop away.

Fresh Pack
Berries destined for “fresh pack” treatment are harvested with a gentler hand because the fruit is going directly to stores where it may sit for four or five days. The berries cannot be wet when raked, and the raker must take care to avoid tearing the skin, which attracts fruit flies and hastens rotting. The harvesting crates are generally filled only halfway so the berries aren’t crushed.

Sort
The rock eliminator moves the blueberries to the tilt belt. Its angled bed allows firm blueberries to roll down to the next part of the packing line. Soft berries, sticks, and leaves don’t roll as easily, so they stay on the tilt belt and are conveyed off the end.

Hand Pick
Packing line workers stand on either side of a conveyor belt, picking out any unripe and damaged berries and other debris that the machines failed to eliminate.

Pack
A worker catches the sorted blueberries in boxes as they fall off the end of the belt. Because they have not been rinsed, fresh-pack blueberries retain the distinctive dusty white bloom that is their natural protection against the sun.

Deliver
Boxes of fresh berries are trucked to stores. They represent less than 1 percent of Maine’s blueberry harvest.

Freeze
The rest of the harvest is stored in a freezer at –15°F.

Process
Because of their fragile nature, wild blueberries are processed for long-distance travel. Ninety-nine percent of the berries are preserved by freezing, though some of these will be canned later. Seven companies operate blueberry processing plants in Maine.

Wash
The berries drop from the rock eliminator into a shallow bath. Green and red berries float to the top, while the blue fruit sinks to the next packing line section. Imperfect berries will be used for juice. At Jasper Wyman & Son, this step is repeated.

Cool and Dry
The berries move through a sanitizing spray of cold water that brings down their temperature in preparation for freezing. A vacuum drier pulls out the excess water.

Flash Freeze
The blueberries are conveyed into the freezer tunnel, which is roughly the size and shape of a tank truck. The temperature inside: -20 to -40°F. At the end of the tunnel, a spinning cylindrical mesh cage eliminates stems and imperfect berries to be used for juice stock. Each berry’s journey through the tunnel lasts about thirteen minutes.

Color Sort
An Elbiscan laser color sorter scans frozen berries, removing anything that isn’t bluish purple and shuttling it into a bin for juice stock.

Hand Pick
The frozen berries get one last inspection, this time by workers who pick out any that are imperfect.

Pack and Store
The berries are collected in bins, to be weighed and boxed. They are stored in refrigerated warehouses until they are trucked to market.