Experts provide a plan to maximize your chances of eating safely at buffets.
The Truth About Temperatures
When it comes to buffets, every expert mentioned this maxim: "Keep hot foods hot and cold foods cold."
Hot buffet foods should be kept at 140 degrees Fahrenheit, preferably at steam tables, which heat more evenly than Sterno burners. Cold foods should be kept at 40 degrees in refrigerated units or ice baths, according to experts.
"When we do inspections at buffets, we're strongly concerned with temperature control," Ong says. That's because proper temperatures help prevent harmful organisms from multiplying to disease-causing levels.
The dangers include salmonella, E. coli, listeria, and noroviruses, which have sparked outbreaks of gastrointestinal illness on cruise ships in recent years. Clostridium perfringens, nicknamed "the cafeteria germ," can also thrive in large portions left for long periods at lukewarm or room temperatures. For example, the bacteria can grow in cooked ground beef that may be used in tacos or casseroles.
When foods go "out of temperature," they enter what experts call a "danger zone" from 40 to 140 degrees. As temperatures move toward about 100 degrees -- roughly a normal reading for the human body -- bacteria multiply fastest, says Craig Hedberg, PhD, an epidemiologist who has investigated food-borne illnesses. He is an associate professor in the Environmental and Occupational Health Department at the University of Minnesota.
"The longer a food item is in the danger zone, the greater the risk of bacterial growth that could lead to disease," he says.
On unannounced inspections, Chase has caught buffet restaurants setting steam tables under 140 degrees. "As soon as we walk in, they turn them up quickly. But it doesn't make any difference because the food's not going to heat up in two minutes before we walk over to the buffet to take the temperature."
Ong also sees operators turning down the heat, for example, to 125 degrees. "They're trying to keep the food palatable," he says. "They don't want the beef stew or chicken casserole to dry out."
Of course, no customer shows up with a food thermometer in her purse. So Ong offers this strategy: at steam tables, stir food and scoop from the bottom, where temperatures are hottest. "The casserole that's at the bottom of the dish, if you stir it up and turn it over a little bit, you could probably get it up to 155 degrees," he says. "When I go to a buffet, I just don't scoop my mashed potatoes from the top. I tend to stir it around a little bit."
If bowls of cold food are held in ice, they shouldn't rest on top, but be set deep, Chase adds. "You want the ice to surround the bowl and come up to the sides of the bowl. If you have an entire bowl of tuna fish, you wouldn't want the ice just on the bottom because then it would only keep the bottom of the product cold."
Ong says food temperatures are less of a concern during busy times, for instance, from the 10 a.m. to 2 p.m. rush period, when food turns over rapidly. While people can still eat safely during slower periods, such as 2 p.m. to 5 p.m., they should watch how carefully the restaurant is replenishing and maintaining the food. Says Ong, "I think it's very dangerous for people to eat later in the day at a buffet if temperature control and food handling is not paramount in the establishment."