In France, a croissant may be breakfast, but in the Bay Area, it is a demonstration of craft.

The Bay Area has seen the spiral pastry evolve from a pale, poofy thing, barely better than a Pillsbury crescent roll, to a marvel of crisp flakes and butter-scented air. In the last few years, in fact, an evolutionary leap on the order of bipedal motion seems to have taken place. These croissants are lighter, higher, more papery than ever.

The explosion of small patisseries has played a role in perfecting the croissant. So has the expertise of master teachers like Chad Robertson of Tartine and Michel Suas of the San Francisco Baking Institute.

Nicole Plue, director of pastry arts at the San Francisco Cooking School, explains why such a simple pastry can be as much of a showcase for a pastry chef as a chocolate-lavender bombe.

“You have to work with the dough when it’s really cold, and butter starts to melt at only 80 degrees,” she says. “It’s a big challenge to keep the butter intact through rolling and folding and rolling and folding,” a process called lamination.

At pastry competitions, Plue says, professional judges take the measure of a croissant by slicing it in the middle, bringing the nose close to smell the aromas of yeast and browned flour, and then pulling away just far enough to study the honeycomb of dough and air.

The Food + Home staff followed her guidelines to survey 13 of the area’s best croissants. Here are the five that are the most polished.

— Jonathan Kauffman, jkauffman@sfchronicle.com

1. Neighbor Bakehouse

Length: 5½ inches

Weight: 2 ounces

Price: $3

Appearance: Delicately flaky exterior ringed with a glossy egg-washed ribbon; interior a logarithmic spiral of increasingly big airholes.

After the first bite of the croissants made by Greg Mindel, a former teacher at the SFBI, you wonder why they don’t float out of your hands.

2343 Third St., Suite 100, San Francisco; www.neighborsf.com

2. Tartine

Length: 5¾ inches

Weight: 4.4 ounces

Price: $4.20

Appearance: Chunky and golden brown, with a nautilus swirl of slim airholes inside.

The densest and heaviest of the croissants surveyed, this is a bread baker’s pastry, with a compellingly wheaty flavor aided by natural leavening and long fermentation.

600 Guerrero St., San Francisco; (415) 487-2600. www.tartinebakery.com

3. Fournée Bakery

Length: 6 inches

Weight: 2.3 ounces

Price: $2.75

Appearance: Deeply colored, flaky exterior and a swirl of air bubbles that grow biggest at the center

Frank Sally, who trained under Michel Suas, says that proper fermentation, aided by a mix of three kinds of starters, gives his croissants their loft and complex flavor.

2912 Domingo Ave., Berkeley; (510) 549-9434. www.fourneebakery.com

4. b. patisserie

Length: 6 inches

Weight: 2.4 ounces

Price: $2.75

Appearance: Golden exterior with stripes of matte and gloss; interior is a spiral network of small, even bubbles.

Michel Suas and Belinda Leong add milk to their croissant, giving it a tender crumb and a milky, delicate sweetness at the finish

2821 California St., San Francisco; (415) 440-1700. http://bpatisserie.com

5. Mr. Holmes Bakehouse

Appearance: Finely detailed layers of sugar-glazed pastry on the exterior and an improbably airy interior.

Ry Stephen says the secret to his croissants is French cultured butter; its olfactory aura extends several feet around the pastry.

1042 Larkin St., San Francisco; (415) 829-7700. www.mrholmesbakehouse.com