Here in the Bay Area, at the heart of the American artisan-chocolate movement, you can savor a dizzying array of the best of both locally made and imported chocolate.

Like wine, chocolate has "terroir." That is, the characteristics of the soil in which it is grown create nuances of flavor. Today's artfully packaged nouveau chocolate bars highlight the point of origin.

According to expert taste buds, Ecuadoran chocolate is "earthy and bold, with tobacco and coffee notes," while chocolate from Madagascar is fruity and spicy, and Venezuelan varieties harbor hints of nut and caramel. And now, daring confectioners are blending these and other chocolates with previously unimaginable flavors including absinthe, curry, wasabi, blue cheese, even bacon.

In search of a Valentine's Day gift and dazzled by options, we had to admit we needed help. So we scanned the schedule of San Francisco chocolate tours conducted by Gourmet Walks, a company founded in 2007 by Andrea Nadel.

Our rendezvous was scheduled for Justin Herman Plaza, where guide Brenna Harrington awaits her charges by posting herself at the central flagpole beneath an umbrella, rain or shine.

After introductions, she launched her opening parry.

"What do you think is the most expensive chocolate in the world?"

Though the group was packed with avid chocolate lovers, even one who makes her own truffles at home, no one guessed. (We won't give it away here, but it's not made in France, Switzerland or Belgium.)

Harrington's entertaining, fact-packed talk continued as we strolled from chocolatier to chocolatier. All the while, she punctuated her remarks with historical tidbits of the kind that improve your depth of vision of San Francisco, even if it's your hometown. Still, chocolate is at the top of the menu.

"The new trend in chocolate is single origin, fair trade and organic," Harrington said. Evidence was plentiful at Fog City News, the elegant Market Street newsstand that is also a veritable library of chocolate from around the world.

There, Harrington proffered examples of Askinosie bars wrapped in rough brown paper, each with a map showing where the cacao inside was grown and a grainy photo of the farmer who grew it.

"They promise their farmers fair wages and a stake in the company's outcome," Harrington said. How San Francisco is that? Very.

As the tour wound to its bittersweet end, we realized that such an experience is a bonding one. Simply put, when you eat that much chocolate with people, they are no longer strangers.

So if you're already in love, Valentine's Day offers a fresh excuse for you and your loved one to bond in a whole new way, by sharing a crash course in the delectable global economy of chocolate.

CocoaBella

Chocolates

8 Westfield San Francisco Centre, 845 Market St., (street level), San Francisco. (415) 896-5222. www.cocoabella.com

Hours: 9:30 a.m. to 9 p.m. Monday through Saturday, 10 a.m. to 7 p.m. Sunday.

Valentine's Day specials: Limited-edition Valentine's Day boxes.

Ghirardelli

Chocolate Shop, Union Square

1042 Stockton St., (between Geary and Market streets), San Francisco. (415) 397-3030. www.ghirardelli.com

Hours: 9:30 a.m. to 8 p.m. Sunday through Thursday, 9:30 a.m. to 9 p.m. Friday and Saturday.

For Valentine's Day: Brownie Bear, a teddy bearing chocolate.

Fog City News

5455 Market St., (between Fremont and First streets), San Francisco. (415) 543-7400. www.Fogcitynews.com.

Hours: 8 a.m. to 6 p.m. Monday through Friday, noon to 4 p.m. Saturday.

For Valentine's Day: Red velvet Moulin Rouge box by Fran's Chocolates.

Scharffen Berger Chocolate

Joseph Schmidt

Confections

4 One Ferry Building, Shop #14, San Francisco. (415) 981-9150. www.scharffenberger.com. josephschmidtconfections.com.

Hours: 9 a.m. to 7:30 p.m. Monday through Friday, 8 a.m. to 7 p.m. Saturday, 10 a.m. to 5:30 p.m. Sunday.

For Valentine's Day: Ribbon-wrapped chocolate bars from Scharffen Berger. Special decorative boxes of truffles from Joseph Schmidt.

Leonidas Belgian

Chocolates

6 50 Post St., Crocker Galleria (street level), San Francisco. (415) 956-2338

Hours: 10 a.m. to 6 p.m. Monday through Friday, 10 a.m. to 5 p.m. Saturday.

For Valentine's Day: Red silk-satin jewelry box of assorted chocolates.

Recchiuti Confections

3 One Ferry Building, Shop No. 30, San Francisco. (415) 834-9494. www.recchiuti.com.

Hours: 10 a.m. to 7 p.m. Monday through Friday, 8 a.m. to 6 p.m. Saturday, 10 a.m. to 5 p.m. Sunday.

For Valentine's Day: Heart-shaped boxes, some made of chocolate.

Richart Chocolates

11393 Sutter St., San Francisco. (415) 291-9600. www.richart-chocolates.com

Hours: 10 a.m. to 7 p.m. Monday through Saturday, noon to 5 p.m. Sunday.

For Valentine's Day: Petit Richart Intense Love collection.

Schoggi Swiss

Chocolates

7 87 Yerba Buena Lane, (on Mission, between Third and Fourth streets). (415) 243-4444. www.schoggi.us

Hours: 10 a.m. to 6 p.m. daily.

For Valentine's Day: Heart-shaped boxes of every size.

Teuscher

of Switzerland

9307 Sutter St., (between Grant Avenue and Stockton Street), San Francisco. (415) 834-0850. www.teuschersf.com.

Hours: 10 a.m. to 7 p.m. Monday through Saturday, 11 a.m. to 6 p.m. Sunday.

For Valentine's Day: Dom Perignon Champagne truffles in fantasy boxes.

XOX Truffles

1 754 Columbus Ave.,

San Francisco. (415) 421-4814. www.xoxtruffles.com.

Hours: 9 a.m. to 6 p.m. Monday through Saturday, 10:30 a.m. to 6 p.m. Sunday.

ForValentine's Day: Special 30-piece Love Box

Tcho

2 Pier 17, on the Embarcadero at Green Street, San Francisco, (415) 981-0189. www.tcho.com/store

Hours: 9 a.m.-5 p.m. Monday through Friday, 11 a.m.-6 p.m. Saturday and Sunday.

For Valentine's Day: Unique chocolate hearts and bar gift packs

E-mail Heidi Benson at hbenson@sfchronicle.com.

This article appeared on page F - 1 of the San Francisco Chronicle