A couple of weeks ago, I was having dinner with my parents. My dad was making chicken and asked me what temperature he needed to cook it to. After all, working for Food Safety News does qualify me as the food-safety expert of the family. “165 degrees F,” I told him. “What if it’s barely pink?” he countered, goading me. “I don’t care what it looks like,” I said. “Use the thermometer!” I try not to be this pedantic about food safety around anyone who doesn’t have to love me unconditionally (it can be annoying, I know), but one of the most important tools for food safety is the thermometer. Two of the four consumer steps toward food safety — Clean, Separate, Cook, and Chill — rely on temperature control. When food contaminated with pathogens such as Salmonella, E. coli or Listeria reaches consumers’ kitchens, cooking to certain minimum temperatures can kill the bugs. Keeping leftovers below 40 degrees F hinders bacteria growth. The safe minimum internal temperatures vary by food. All poultry, casseroles and leftovers should be heated to 165 degrees F. Ground meats and egg dishes need to be at least 160 degrees F. Fresh beef, pork, veal, lamb and ham should reach 145 degrees F and then rest for at least three minutes. Fish should also be cooked to 145 degrees F. “Using thermometers is the only way to really know that your food is thoroughly cooked — that it has reached a temperature to destroy any harmful bacteria that could possibly be there — and thermometer use is also important in the refrigerator in chilling,” says Christine Bruhn, retired director of the Center for Consumer Research at the University of California. But few consumers actually use a thermometer to check the doneness of meat, poultry and seafood, or to check the temperature in their refrigerators. “They might do it on a roast, they might do it on whole chicken,” Bruhn says. “They don’t do it on the smaller chicken parts, they seldom do it on burgers, and even on steaks they are relying on visual indicators. They’re not really verifying the temperature on the inside.” How many use thermometers for cooking? Self-reported use of thermometers has increased from 33 percent in 1998 to 53 percent in 2010. This seems like great progress, but Bruhn warns that people may only use thermometers on large hunks of meat or poultry, such as a pot roast or the Thanksgiving turkey, and not necessarily in everyday cooking. People might also say they use thermometers even though they don’t just because they know they’re supposed to. According to a survey conducted by the U.S. Food and Drug Administration, 46 percent of participants said they never use a thermometer when cooking chicken parts and 66 percent said they never use one when cooking or grilling hamburgers. Last year, while studying various aspects of chicken preparation in consumer homes, Bruhn found that only 5 percent of participants used a thermometer without prompting from the researchers, and only about a third agreed to do so when prompted. From there, researchers found that 40 percent of the chicken in the study was undercooked, especially when it was grilled or barbecued. According to another study published last month and conducted by RTI International, Tennessee State University and Kansas State University, 62 percent of consumers own a food thermometer, but less than 10 percent of them actually use it to check for doneness in all poultry. Addressing barriers to thermometer use in cooking Bruhn says that the main barriers to thermometer use are the idea that using a thermometer implies inexperience and the thought that cooking meat and poultry to the recommended minimum temperatures degrades taste. Most home cooks use visual indicators such as color, firmness, clear juices or shrinkage, but these aren’t accurate indicators of doneness. For example, a chicken breast could turn white, but still be less than 165 degrees F. Many recipes refer to these visual cues or to cooking time. Bruhn says that time is only reliable if there is consistency across everybody’s frying pan or oven and the food always starts out at the same temperature. To get more consumers to rely on thermometers, anyone writing recipes for a book, magazine, or blog should include the temperature recommendations, Bruhn says. “That could so simply be added to a recipe” and would mean consumers wouldn’t have to keep all the correct temperatures in their head, she adds. Another way to show people that using thermometers isn’t an amateur move is for “role models” to use them. Bruhn’s hope is to reach celebrity chefs and their producers to stress the impact they could have by “modeling correct and safe behavior for the public.” As for the thought that your chicken or burger will be too dry if you cook it to the recommended temperatures, many food-safety experts argue otherwise. For chicken, “We found that at 165, it’s still moist and juicy,” Bruhn says. “If you want it to be dry, bring it up to 180 or something like that.” As for ground beef, the U.S. Department of Agriculture says that burgers can still be juicy when cooked to 160 degrees F, regardless of color. If you still have your heart set on that rare or medium-rare burger, go ahead and order it, but just know that it’s a risk, Bruhn says. “That’s one of the dilemmas I face as an educator: seeing people doing things that I would not do. But if they consciously choose to take that risk, then I need to seal my lips,” she says. “If they don’t know any better, then I can find a gentle way to let them know it’s a high-risk action.” How many use thermometers for chilling? In that FDA survey, 55 percent of consumers said their refrigerator didn’t have a built-in thermometer. Only 21 percent of respondents said they put a thermometer in the fridge to check its temperature. People tend to trust that the refrigerator is going to be cold enough when relying on its factory settings. This might be OK, Bruhn said, but things can change over time. In her studies, Bruhn says she’s seen around 13 percent of consumers’ refrigerators with temperatures above 45 degrees F (the recommendation is 40). Bruhn says she would love to see fridge manufacturers “be more assertive” in including thermometers in their products. Some of the high-end ones do, but not all, and she wonders about those who can’t afford one of those. “Food-safety standards should be made available to all income groups,” Bruhn says. And, in her chicken study, only a quarter of participants knew the correct temperature for their fridges. When adding thermometers to refrigerators, Bruhn suggests that manufacturers include a scale to indicate whether the appliance is in the safe range. “We don’t all need to have numbers bouncing around our head, but we need to know where we are,” she says.

  • Katie Nakle

    It’s important to note that if the thermometer reading is too low and needs to be reinserted after cooking the food longer, it needs to be thoroughly washed before reinsertion.

  • alocalcitizen

    In addition washing the thermometer again before reinsertion, thermometers should have the NSF logo on them http://en.wikipedia.org/wiki/NSF_International and be capable of being calibrated. Thermometers should be recalibrated monthly. http://www.foodsafety.unl.edu/haccp/helpful/thermcalibration

    • Angus McAngstybritches

      Wow. I was just thinking how maybe I should get on board with this, but I seriously have to keep it calibrated? Monthly? I’m already having trouble keeping up on my testicular self-exams between hard drive to back-ups, water heater flushes and all these website terms of service to scrutinize.

    • Tom Woodbury-Chef

      Interesting point. I struggle with the calibration aspect of most modern day digital thermometers, if a thermometer built with a thermistor goes out of calibration, it’s likely due to a mechanical shock to the sensor. In that scenario, no amount of calibration will bring the thermometer back to an acceptable temperature accuracy across the range of food safety temps.
      While this is a common problem in the old bi-metal stem thermometers, the current best practice in pocket digital thermometers is to “verify accuracy” as opposed to calibrating accuracy.

  • AuntyMM

    how did humanity ever survive without knowing the temperature of their food in degrees F? it’s sad that we have become so inept and dependent on complicated technologies.

    • Liz de Boisgelin

      Perhaps the food in the good old days didn’t come ready contaminated!

      • Mark Osborne

        courtesy of big AG…per-innoculated for your convenience

      • oldcowvet

        Or perhaps not. I learned at the feed of my grandma that food needs to be handled properly.

      • katienakle

        Good point! The way animals, particularly chicken, are raised now has increased the prevalence of food-borne illness. I don’t recall the specific statistics, but in studies almost ALL chickens have been shown to carry pathogens capable of causing food poisoning, thus making it more important then ever to properly cook and check internal temperatures of chickens as well as all other meats.

    • deserteeyore

      The same way it survived without pastuerization, vaccines, medication or fire to cook food at all. Humanity will survive, but there will be many more individuals who do not. If you are feeding anyone other than yourself, you are obligated to ensure the food they are eating is safe. Not guessing it is based on the length of time it cooked or assuing it is based on its color.

    • LogicPolice

      By reproducing at a rate that exceeded the rate of mortality. Not trying to be snarky here but since early man right up through the industrial revolution, those were some pretty rough times. Pick your contagion, whether food borne or the hearth as a fomite, generations were lost.

      • AuntyMM

        it’s a good thing that they didn’t all survive then, because we would be knee deep in homeless people by now and climate change would have already led to an increase of 5C in global mean temps.

        • LogicPolice

          Agreed

  • Ellen

    And where is the link to the article about how to buy and use a thermometer properly? If I am going to rely on a thermometer, someone needs to tell me what to look for in a thermometer. I have ruined (as in overcooked) meat more than once using the thermometers that I have purchased.

  • Achyut

    Make sure you calibrate your thermometer to measure within within +/- 2° F (1.1° C) of the actual temperature simply through using an ice water solution or boiling water.

  • Amorette

    I own several food thermometers and use them regularly. I give them as gifts. I have had salmonella, thank you, and would prefer to avoid it again.

  • Brian Raden

    Yes I believe that it is very important to use a meat thermometer. I’ve heard stories about people getting quite ill by not cooking meats thoroughly and one way to prevent this is by using a reliable meat thermometer.