UF/IFAS Food Safety Expert Provides Scoop on Holiday Leftovers

Clint ThompsonFlorida

Getty images: Photo courtesy of UF/IFAS: View at a fridge full of fresh raw food and a person choosing a container of veggies they’re going to have for lunch.

When it comes to holiday planning, the last item on anyone’s list is a bout with food poisoning.

“Most people are lulled into a false sense of security because foodborne illnesses are rare,” said Keith Schneider, a University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) food safety expert in the UF/IFAS food science and human nutrition department. “You think, ‘I’ve never gotten sick. Why should I do anything differently?’ Well, you don’t want this year to be the one time you lapse in your food safety practices and grandma gets sick.”

But how rare are such instances? According to Dr. Matthew Shannon, a UF Health emergency medicine physician, the holidays often bring an uptick in foodborne illness to the emergency department.

Schneider shares his top tips for meals with leftovers, while minimizing the chances you’ll find yourself in the emergency room.

1. Keep cooked foods out of “danger zone.”

Keith Schneider

“Bacteria multiply between 40 degrees and 140 degrees Fahrenheit. But since most people aren’t monitoring those temperatures closely, you want to be sure to refrigerate any leftovers within two hours of being cooked or being removed from the heating source. If you’re going to leave a dish on a warming tray or in the oven, for example, you’ll want to cool it down before putting it in the refrigerator.”

2. For foods that are served cold, the same “danger zone” applies.

“Your refrigerator is typically set at 38 degrees to 40 degrees. Any of the pathogens of concern are not going to grow below 40 degrees. So, when you take out, say, a salad or a pumpkin roll with cream cheese filling, that also shouldn’t spend more than two hours above 40 degrees. But the higher the temperature outside the refrigerator, the shorter the time it should be out.”

3. Use shallow containers to ensure adequate airflow and even cooling.

“Say you have piping-hot gravy that was kept in a hot dish. You don’t want to throw that right into the refrigerator because it has all that residual heat. You want to make sure that when you’re putting it in the refrigerator, you’re allowing for maximum cooling. This includes transferring to shallow storage dishes, allowing to cool some before refrigerating, and ensuring airflow above, below and around to facilitate the cooling. If you stack everything, and you have a holiday load of food going into the refrigerator, it could take hours and you could literally heat up the whole refrigerator.”

4. Most items can go into either the refrigerator or the freezer.

“In general, if you think you might not eat something within three to four days, which is the general limit in the refrigerator, freezing would be a better choice. If you have vacuum-sealable bags, that’s a better storage solution, since issues with frozen foods tend to be more on the quality side than safety. Otherwise, it’s the same process as the refrigerator, giving proper airflow around the food. Using frozen leftovers sooner rather than later will eliminate some of those quality issues, like freezer burn.”

5. The “smell test” isn’t good enough.

“Pathogens typically don’t grow to a density where they’re going to have an odor. The odor typically occurs from spoilage. So, if it smells bad, of course, don’t eat it. But if it’s been a few days and still smells fine, it still may not be safe. As I often say, ‘When in doubt, throw it out.’”

6. Reheat leftovers to 165 degrees Fahrenheit.

“What you want to do is take out the portion that you’re going to eat, as opposed to the entire dish. Whatever you plan to consume, you want to get to that temperature to kill any pathogens that may have germinated. For turkey, as an example, the organism of concern post-cooking is clostridium, which will die at 165 degrees. But it’s a spore former, and the spore will survive high-temperature cooking; then when it cools, it will germinate and start growing again.”

7. Minimize heat-thaw cycles.

“Foods served cold don’t have that kill step option. You want to be sure that you’re preventing cross-contamination for these foods. Ensure that they’re in sealed containers and be aware that every time you remove from the refrigerator, each thawing cycle adds heat energy that allows pathogens to grow. The problem is that it’s a cumulative thing – two hours out of the fridge the first day, plus an hour the next, and it adds up to accumulated growth.”

8. Your leftover sandwich is fine cold, providing you cooked it properly to start.

“As long as your turkey and other ingredients were cooked and stored properly, the pathogens aren’t going to magically grow. If you’re worried about it, sure, you can heat the turkey and have a warm sandwich.