For centuries, Asians have celebrated the harvest festival with Moon Cakes. But the fist-sized golden brown pastries, filled with sweet bean paste, egg yolks and nuts, aren't just for the harvest anymore. Moon cakes have also become culinary delicacies for the lunar new year, observed this week in Asian communities around the world. In San Francisco, such popularity has gained moon cakes what some say is unnecessary attention from health officials and the California state legislature.

Customers wait patiently outside the Golden Gate Bakery

On Grant Avenue in San Francisco's Chinatown, the line for moon cakes outside the Golden Gate Bakery stretches around the block, and the wait can be 30 minutes long. Inside, crowds gather around racks filled with dozens of varieties of chewy moon cakes. "We have mixed nuts, coconut nuts, this one is a white lotus," Virginia Woo points out as she takes customers' orders.

Lisa Chan's family has been coming here for years. "Oh, they are very good," she says, adding, "Chinese people normally like things fresh." The Chans buy moon cakes by the box-full and leave them out on the counter to be enjoyed. "We usually eat them within a week or two," she says.

But that's what worries Kevin Reilly, at the California Department of Health, who says "They do have the potential of growing bacteria and causing problems, illness, food-borne illness."

Orange County, in southern California, is home to 135,000 Vietnamese-Americans. The health department there is insisting that stores refrigerate moon cakes if they plan to keep them on display for more than just four hours. Other counties are considering similar rules.

Van Tran has been a member of the California State Assembly since November 2004

And that's raised the ire of Van Tran, the only Vietnamese-American member of the California legislature. He points out, "These types of foods have been consumed for hundreds, if not thousands of years, without any significant health issues."

Assemblyman Tran says there are many reasons to keep moon cakes out of the refrigerator. "If you put the moon cakes in to the fridge, anything that's lower than 40 degrees [Fahrenheit], it would not taste the same, because it would be basically a hockey puck. The texture of the cake would be a solid object, and it would be a health hazard if you bite it," he observes with a chuckle.

Tran took the moon cake dilemma to the legislature, and passed a bill that directs the California Department of Health to actually study moon cakes before they regulate them.

Yong Chen says the government should study moon cakes, not regulate them

But even that seems a slap in the face to some. Professor Yong Chen, who researches food and culture at the University of California Irvine, says the very act of investigating the safety of moon cakes is demeaning to Asians, who've eaten them for centuries. "To tell Asian-Americans to put the moon cakes in a refrigerator, that's just being culturally insensitive. It's also ignorant of the long history behind it. It has always been safe for so many centuries. Why, all of a sudden, do we need to do this?"

Chen says scientists should be learning about food safety from moon cakes, not imposing new rules on them. "Food safety is based on Western science," he says, "and that emerged since the late 19th century. And that's very limited culturally. And it doesn't take into consideration culinary traditions other than Anglo-American."

Salesclerk helps a customer at the Golden Gate Bakery

So, for this lunar new year, many Asian bakeries in California still have displays like the one at Golden Gate: more than 100 moon cakes crowd the shelves - each about 4 centimeters thick. Their sunrise-yellow crusts are embossed with Chinese letters that name the bakery and identify one of dozens of possible fillings. The moon cakes are not wrapped, and they sit at room temperature, just as safe to eat today as they have been for centuries. But next January, when the Health Department's report is due, ancient Asian tradition may collide with modern Western science.