Carolyn Wyman ate all kinds of cheesesteaks while researching her just-released The Great Philly Cheesesteak Book.

Her homage to the steak sandwich traces its eight-decade history from Pat Olivieri's hot dog grill at Ninth and Passyunk to its current variations, including the chicken steak and something the vegetarians call a cheesefake.

She hit about 50 spots, sampling cheesesteak spring rolls at the Four Seasons Hotel and cheesesteak pierogi from Czerw's. She got the recipe for cheesesteak soup from Campbell's.

Le Bec-Fin was not on Wyman's radar.

But she and chef-owner Georges Perrier have something in common: They appreciate a good academic exercise.

How would Perrier fix a cheesesteak? And what would Wyman think of it?

A Philly cheesesteak, as Wyman explains, "is not just bread, meat and cheese coming together."

It's a Philadelphia cultural icon - a subject of love and loyalty, politics and pride, history and hubris. It's brought families together (the Campos, whose kids work with their parents in the Old City sandwich shop) and torn them apart (the Olivieris, who founded Pat's King of Steaks and whose cousin owns Rick's in the Bellevue's food court and who have traded lawsuits).

Cheesesteaks are a new subject to Wyman, 53, who was raised on Steak-umms in New England. When she arrived in Philadelphia about seven years ago, "I would bike around and see all these restaurants had [signs for] 'steak' in the window," she said. "I was from a place where steaks were steaks - what they put on black eyes in cartoons. I thought, 'These people are really into beef' - until I learned better."

Wyman and her husband, Philip Blumenkrantz, first sampled Pat's and Geno's, the rivals across the corner of Ninth Street and Passyunk Avenue. "That's really the extent of cheesesteaks for a lot of locals," she said.

She had written books about single ingredients such as Spam and Jell-O, and seized upon the topic of cheesesteaks. Running Press bit.

The book is a travelogue studded with sidebars describing minutiae such as the many variations of meat and condiments. For good measure, tucked inside the back cover is a DVD of the locally produced documentary This Is My Cheesesteak.

The project is as much anthropology as it is about food.

"Steak shops reflect the character of their neighborhoods," Wyman said. "Having eaten at all these places, I found that what makes these local shops so great are the people who serve them to you."

When asked who makes the best steak in Philly, she was quick to reply: "This book is not a contest." She acknowledged her favorites as Johnny's Hots, Donkey's, Grey Lodge Pub, Philip's, Talk of the Town and Sonny's for "slab-style" beef, and Claymont, Dalessandro's and Pagano's for chopped-up steaks.

She's sampled Cheez Whiz, American and provolone.

Never Gruyère.

And she never ate a cheesesteak served on Villeroy & Boch china.