Experts Debate Germy Potential of Potluck Parties

Dec. 24, 2008 — -- Potluck meals, those gatherings of shared food and friendship, a holiday staple, can send some running in the other direction.

"I always have this fear [about potlucks]," said Natalie Wardel, 23. "I'm a picky eater and I like to know where my food has been."

Food habits aside, Wardel may be wise to avoid potlucks and other social events where people bring cooked food to share. Proper food safety techniques, particularly regarding food temperature, are hard to control at potlucks, so the chance of encountering bacteria or viruses in food that cause illness can increase.

The cardinal rule for serving food is keeping it at the correct temperature.

Cold foods should be kept cold, and hot foods should be kept hot, not warm, stressed Dr. William Schaffner, chair of the Department of Preventive Medicine at Vanderbilt Medical School.

"The danger comes when foods are kept at prolonged room temperature," Schaffner said. "If the food happens to be contaminated, you get multiplication of the bacteria."

Hot or cold foods -- which tend to be main courses -- left at room temperature longer than two hours could be incubating bacteria such as staph and salmonella, which cause food poisoning, or viruses such as norovirus, which can cause diarrhea. As food temperature rises above 40 degrees or drops below 130 degrees, the chances of microbe growth increase.

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Also, food may remain out until well after the first round of eating. By the time guests go back for seconds or if new people arrive late, dishes may have been sitting out for several hours.

Others are less concerned about potlucks, though the time food sits out can still be a problem.

Mark Kantor, an associate professor of Nutrition and Food Science at the University of Maryland, is more concerned with what happens to the food after all the guests have gone home.

"You probably shouldn't keep leftovers," Kantor said, noting that by the time the party is over, food will have been sitting at room temperature well beyond the recommended two hours.