By AnnaMarie Koehler-Shepley
Imagine the world’s most perfect chocolate chip cookie.
With melted chocolate chips tucked inside a bed of cookie dough that is somehow lightly crisp on the outside, yet still gloriously gooey on the inside, the perfect cookie is delicious and warm, straight from the oven, with tiny steam puffs spiraling above it.
Now, imagine that right as you’re about to put this world’s most perfect cookie into your mouth, it falls to the ground.
If you’ve ever heard of the 5-second rule, you might just pick it up. After all, the world’s most perfect cookie must be just as resilient as it is scrumptious, right?
According to a recent study published by Rutgers University in “The Journal of Applied and Environmental Microbiology,” bacteria transfers almost instantaneously between surfaces, which means that even one second could be a second too many.
The study, “Is the Five Second Rule Real?”, was conducted by Donald Schaffer, a Rutgers’ professor and extension food specialist. He found that in some instances bacteria were transferred to fallen food in less than a second.
The study tested four different foods fallen onto four different surfaces for four different contact times. Researchers discovered that the bacteria transferred almost instantly and that the longer the food was on the surface, the more bacteria it had picked up. The results also showed that the wetter the surface or the food, the more bacteria transferred, likely because moisture facilitates the spread of bacteria.
This means that while it might seem like common sense, when food hits the floor, even in your own home, there is a transfer of bacteria.
While many bacteria are harmless and some, like probiotics, are even good for you, Christine Bruhn, consumer economics specialist emerita from the University of California – Davis and fellow at the Institute of Food Technology, says that that’s not a universal rule.
“Some will kill you, though,” she said. “We all have to be careful.”
To complicate things, many people also have an optimism bias, said Bruhn, which means most people think that their neighbor is far more likely to fall ill than they are.
Particularly, she says to be wary of certain strains of E. coli and salmonella that can put individuals who are more susceptible to food-borne illnesses in the hospital or take their lives.
In the name of safety, here are a few other food-safety guidelines to be mindful of.
Tastes like chicken
Firstly, Bruhn advises everyone to make sure that their food, especially meat, is actually cooked before it touches their lips. Just because it might look cooked-through, that is not always the case. This is especially important when dealing with leftovers that can be heated irregularly or unevenly in the microwave.
“Don’t rely on steam or color change,” she said. “It’s not always an adequate indicator.”
The best way to make sure that food is fully cooked is to measure its temperature, Bruhn says. The general guidelines are 165 F for leftovers and chicken, and 160 F for beef.
We’ve all been there: at a party, tailgate or cookout where the food has been sitting out all day. It looks ok, but is it really safe to eat?
The longer food is left out, the more time bacteria have to multiply, Bruhn says. The general guideline is that anything left out more than two hours is not safe to eat.
The problem is that when the food is no longer piping hot or freezing cold, it becomes a playground for bacteria.
“You need to get it out of the danger zone—the temperature where bacteria can multiply,” Bruhn said, “which is between 40 degrees and 120 degrees Fahrenheit.”
Do I really need to wash my produce?
“The answer is yes, yes yes,” Bruhn said.
Even if you’re buying organic, pesticides can still be used. On top of that, she said, there is dust and dirt that can contain fecal matter from animals.
“You want to rinse all that stuff off,” she said.
Her recommendation is just a quick rinse and then a pat dry. The good news, though, is that pre-washed greens are perfectly ok to go straight from the bag to your plate.
Licking the spoon
Lastly, while some people might argue that licking batter off the spoon is the best part of the baking process, most people know that they shouldn’t do it.
Eating raw eggs puts you at risk for salmonella, which has the highest death rate among common food borne illnesses, according to Bruhn.
“For many years, it was thought that you can eat it raw if it didn’t have eggs in it,” said Bruhn. “But just this year, they’ve found a strain of E. coli in the flour.”
This means that eating all kinds of raw dough comes with risks, even if the recipe doesn’t include eggs.
As hard as it is, the safest bet is to save your taste-testing until the cookies are out of the oven.
Who knows? Maybe the world’s most perfect cookie will be waiting for you on the tray—just don’t drop it.